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Review

Constructed Wetlands for the Wastewater Treatment: A Review of Italian Case Studies

by
Berhan Retta
1,
Elio Coppola
2,*,
Claudia Ciniglia
2 and
Eleonora Grilli
2
1
Department of Engineering, University of Campania Luigi Vanvitelli, Via Roma 29, 81031 Aversa, Italy
2
Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania Luigi Vanvitelli, Via Vivaldi 43, 81100 Caserta, Italy
*
Author to whom correspondence should be addressed.
Appl. Sci. 2023, 13(10), 6211; https://doi.org/10.3390/app13106211
Submission received: 27 April 2023 / Revised: 12 May 2023 / Accepted: 16 May 2023 / Published: 18 May 2023
(This article belongs to the Special Issue Novel Technologies for Wastewater Treatment and Reuse)
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Abstract

:
Wastewater is one of the major sources of pollution in aquatic environments and its treatment is crucial to reduce risk and increase clean water availability. Constructed wetlands (CWs) are one of the most efficient, environmentally friendly, and less costly techniques for this purpose. This review aims to assess the state of the art on the use of CWs in removing environmental pollutants from wastewater in Italy in order to improve the current situation and provide background for future research and development work. To evaluate the CWs performances, 76 research works (2001–2023) were examined, and the parameters considered were the type of wastewater treated, pollutants removed, macrophytes, and the kinds of CWs utilized. The pollutant removal efficiencies of all CWs reviewed showed remarkable potential, even though there are biotic and abiotic factor-driven performance variations among them. The number of articles published showed an increasing trend over time, indicating the research progress of the application of CWs in wastewater treatment. This review highlighted that most of the investigated case studies referred to pilot CWs. This finding suggests that much more large-scale experiments should be conducted in the future to confirm the potential of CWs in eliminating pollutants from wastewater.

1. Introduction

Environmental degradation can be caused by both anthropogenic and natural sources of pollution. Anthropogenic pollution associated with the industrial and agricultural sectors, for instance, is contributing immensely to environmental deterioration, especially in the aquatic ecosystem [1,2]. Domestic and municipal wastewater, sewage from wastewater treatment plants, urban runoff, livestock wastewater, stormwater, and landfill leachate are other major sources of pollution to the aquatic environments. If wastewater coming out from these sources is released into a natural water body without proper treatment, it results in an algae bloom [3,4] that affects aquatic biodiversity [5]. Moreover, it can contaminate soil and groundwater, endangering human health [6]. Consequently, the remediation of polluted water is vital to both reduce such risk and increase clean water availability. Indeed, as recently highlighted by [7], wastewater treatment could contribute to achieving 11 out of 17 sustainable development goals (SDGs) adopted by the United Nations, considerably reducing the global water crisis. Nowadays, the use of green technologies for such purposes is increasing due to (i) their ability to reduce pollution without compromising environmental sustainability and (ii) low implementation and maintenance costs [8]. Among these emerging green technologies, phytoremediation is being recognized as a promising, low-risk, and environmentally friendly in situ clean-up method, where plants are used to decontaminate the environment by eliminating, holding, or providing nontoxic contaminants in soil or water [9,10,11]. Phytoremediation was successfully used in constructed wetlands (CWs), an artificially built pollutant removal method that utilizes the combined contribution of substrates, macrophytes, and microbial community [9]. CWs are designed and built engineering systems that use the natural processes of emergent/floating/submerged wetland plants, saturated or unsaturated substrates/soils, and associated microbial communities built for water pollution control [12,13,14]. They are synthetic systems that have been designed to resemble the biological, chemical, and physical processes that take place in natural wetlands [15].
With the use of CWs, wastewater remediation can be conducted more affordably, sustainably, and easily, with a high rate of nutrient recovery, and minimal maintenance/operation costs [16,17,18,19] in an eco-friendly way [20,21]. CWs are capable of treating wastewater from different sources such as municipal, livestock, industrial, agricultural, domestic, acid-mine waste, storm run-off, and landfill leachate [22,23,24,25,26,27,28,29]. Numerous harmful chemicals, including antibiotics, heavy metals, landfill leachate, textile dyes, pesticides, hormones, petroleum, and explosives are removed or degraded by the phytoremediation technique [30]. With the help of CWs, a variety of pollutants can be eliminated from wastewater, including biochemical oxygen demand (BOD), chemical oxygen demand (COD), suspended solids (SSs), total Kjeldahl nitrogen (TKN), total phosphorus (TP), total coliforms (TCs), and metals by microbial degradation, plant absorption, substrate adsorption, and filtering by the packed media and biological predation [26,31].
This review article focuses on the research works conducted with different kinds of CWs, macrophytes, and substrates in Italy from the year 2001 to 2023, in order (i) to assess the current status about the use of CWs for wastewater treatment, and (ii) to provide useful information for future researchers. The bibliographic research was conducted using some of the most important popular and scientific search engines (Scopus, ScienceDirect, Web of Science, SpringerLink, Google Scholar, and ResearchGate) by entering different keywords, i.e., CWs, wastewater, and Italy.

2. Classification of CWs

CWs are divided into three classes based on the water flow regime [25]: free water surface flow (FWS) CWs, sub-surface flow (SSF) CWs, and hybrid systems (Figure 1).

2.1. Free Water Surface Flow (FWS) CWs

In this system, the wastewater flows through a shallow, planted basin or channel. It has exposed water surfaces and macrophytes that simulate natural wetlands [32], and as a result, high wildlife diversity is expected (insects, molluscs, birds, mammals, etc.) within the large land area required [33]. FWS CWs are reportedly employed less frequently due to the significant risk of human exposure to pathogens [34]. However, it can be utilized in rural areas where access to land is typically better than in urban areas. The wastewater being treated here must have effectively completed secondary or tertiary treatment elsewhere to avoid the system becoming clogged with solids. TSS, COD, BOD5, and pathogens, such as bacteria and viruses, can all be removed with an effectiveness of greater than 70% [35].

2.2. Sub-Surface Flow (SSF) CWs

It is a type of CWs, the porous substrate media allows the wastewater to flow either horizontally or vertically beneath the surface. According to [36], SSF CWs are efficient in carbon and nitrogen compound removal because of the aerobic nature of the media. SSF CWs usually classified into two, depending on the direction of the water flow: horizontal sub-surface flow (HSSF) and vertical sub-surface flow (VSSF) CWs [37].

2.2.1. Horizontal Sub-Surface Flow (HSSF) CWs

In HSSF CWs, the wastewater moves horizontally below the surface through the substrate media, plant roots, and rhizomes towards the system outlet [24]. According to [38], unlike the FWS CWs, HSSF CWs require a small land area but with high investment costs. HSSF CWs are poor in removing ammonia nitrogen (nitrification) but because of anoxic and anaerobic conditions, they can treat nitrate nitrogen (denitrification) very well [15]. TSS, BOD5, and COD were reported to be effectively removed by HSSF CWs at rates of 83.9%, 79.2%, and 72.1%, respectively [25].

2.2.2. Vertical Sub-Surface Flow (VSSF) CWs

The wastewater in VSSF CWs moves vertically either as an up-flow or downflow [39] movement. In a downflow movement, wastewater is applied intermittently (with filling and draining) and it inundates the surface before entering the system through gravity [40,41]. As wastewater passes through the medium (substrate), air enters the pores and facilitates the nitrification process [42], hence improving pollutant removal efficiency. This process can be further improved by inserting aeration pipes in the system [35]. Clogging in this system may be caused by degraded macrophytes, pollutants, and particles in the system affecting the hydraulic conductivity that influences the treatment process [43]. VSSF CWs are well-aerated (aerobic condition); therefore, ammonia nitrogen is removed through the nitrification process but not nitrate nitrogen because of the absence of denitrification [15]. According to [25], TSS, BOD5, and COD removal efficiencies for VSSF CWs were found to be 81.8%, 80.0%, and 78.7%, respectively.

2.3. Hybrid CWs

Hybrid system is a combination of various types of CWs. This system is capable of removing ammonia, nitrate, and total nitrogen from different types of wastewater by combining VSSF CWs with HSSF CWs [44]. The very high pollutant removal efficiency of hybrid CWs is due to the presence of aerobic, anaerobic, and anoxic phases [24,32,45]. Hybrid systems outperform single-stage systems in the removal of TSS (91.2%), BOD5 (82.7%), NH4-N (77.6%), TN (73.3%), and TP (69.9%), as well as other contaminants, when compared to other types of treatment wetlands [25].
Applsci 13 06211 g001 550
Figure 1. Top to bottom, CW with free water surface (FWS), CW with horizontal sub-surface flow (HSSF, HF), 1 inflow distribution zone filled with large stones; 2 impermeable layer; 3 filtration material; 4 vegetation; 5 water level in the bed; 6 outflow collection zone; 7 drainage pipe; 8 outflow structure with water level adjustment, CW with vertical sub-surface flow (VSSF, VF) (Vymazal, 2007) [39].
Figure 1. Top to bottom, CW with free water surface (FWS), CW with horizontal sub-surface flow (HSSF, HF), 1 inflow distribution zone filled with large stones; 2 impermeable layer; 3 filtration material; 4 vegetation; 5 water level in the bed; 6 outflow collection zone; 7 drainage pipe; 8 outflow structure with water level adjustment, CW with vertical sub-surface flow (VSSF, VF) (Vymazal, 2007) [39].
Applsci 13 06211 g001

2.4. Macrophytes

Wetland plants are classified as emergent plants, floating leaf macrophytes, submerged plants, and freely floating macrophytes [46]. Macrophytes are components of the CW treatment systems that play major roles in the breakdown and removal of nutrients and other contaminants. Aquatic macrophytes are widely employed in wastewater treatment because they grow more quickly, produce more biomass, and have a higher capacity to absorb and store pollutants [47,48]. Through photosynthesis, macrophytes in CWs can also act as a reliable source of energy (carbon from root exudates) for microorganisms [17], and in the rhizosphere, macrophytes offer surfaces and oxygen for the growth of microorganisms [49]. Phragmites australis, Typha latifolia, Lemina minor, Arundo donax, Cyperus alternifolius, Canna indica, and Cyperus papyrus are some of the aquatic plants used in wastewater treatment.

2.5. Substrate

The substrate in CWs is usually constituted of soil, sand, gravel, or organic matter such as compost [50]. It is a crucial component of CWs performing several functions, including the following: physical support for wetland plants [51]; controls hydraulic conductivity and plant growth [52]; removal of pollutants by ion exchange, adsorption, precipitation, and complexation [49,53,54]; electron donor function for metabolism and denitrification; and carrier function for microorganisms. For such reasons, CWs substrate has a big impact on the implementation costs, as well as the effectiveness and sustainability of the treatment [51]. Specifically, the substrate in CWs strongly affects the performance of microorganisms by providing aerobic and anaerobic zones that promote denitrification, nitrification, adsorption, ion exchange, and precipitation processes with organic carbon as an accessible energy source [13,55,56].

3. Discussion

The application of CWs in wastewater treatment becomes more common in different parts of the world. Similarly, this review found that the number of published results in the first 11 years (2001–2011) was small in number than the following 12 years (2012–2023), showing how familiar the CWs technique becomes in Italy. Of the 76 articles reviewed, 2 were about laboratory experiments, 30 were large-scale experiments, and the remaining 44 referred to pilot projects. It has been reported that the pollutant removal efficiencies of all the CWs reviewed in this article showed remarkable potential, even though there are biotic/abiotic (physical, chemical, and biological processes) factor-driven performance variations among them. For instance, photolytic degradation, sorption, plant uptake, microbial degradation, type of CWs, plant type, operational mode, soil matrix, hydraulic retention time, hydraulic loading rate, research location, climate, etc. might have caused the observed removal efficiency differences among the CWs. Table 1 summarizes the types of CWs, locations, plants used, wastewater treated, pollutants, and their removal efficiency (RE%), which are the common operational parameters reported in all the 76 reviewed articles.
Biotic and abiotic factors can have a significant effect on the pollutant removal efficiency of CWs. For instance, according to [57], nutrient removal is controlled by the pH of the treatment system in CWs. A reduction in the NH4+-N removal rate from 7.8 ± 1.2 g/m3/d to 6.4 ± 1.3 g/m3/d corresponding to a reduction in pH from 8.1 to 7.6 was reported [58]. Similarly, research results indicated significant differences in wastewater treatment capacities among plants [59,60,61]. Some researchers [62] reported removals of ammonium and phosphate ions from a pig industry effluent that ranged between 59–84% and 32–92%, respectively, in CWs with Phragmites australis, and 62–75% and 7–68% in CWs with Typha latifolia. In the same manner, differences in the removal of pollutants among plants were also observed in this review. For example, the benzene removal potential (%) of a horizontal subsurface CW in South Italy showed different values using Phragmites australis (39.78%) and Typha latifolia (35.14%) [63]. The types of microorganisms present in a CW also affect the removal efficiency. Organic matter biodegradation is correlated to autotrophic and heterotrophic bacteria, fungi, yeast, and protozoa [64,65]. The presence or absence of these microorganisms in the CWs of the reviewed Italian works possibly contributed to the observed performance variations.
Temperature determines the rate of metabolic activities and impacts microbial populations [66]. Ref. [67] stated a significant (p < 0.05) positive impact of temperature on the rate of organic matter degradation, nitrification, and denitrification processes in less time. The success of treatment in a CW often declines at cold temperatures, mostly due to decreased biotic activity [15]. For instance, the rate of ammonium oxidation is greatly reduced when the temperature drops below 10 °C [68]. Moreover, ref. [69] reported 7% and 9% improved removal efficiencies of ammonia nitrogen and nitrate nitrogen, respectively, in constructed wetlands in summer than in winter. The reviewed Italian case studies were conducted under different temperatures and seasons, which are expected to cause performance variations.
Hydraulic retention time or the amount of time contaminants are in contact with the substrate and the rhizosphere of plants is widely known to be a significant controlling element in determining the effectiveness of pollutant removal [33,70,71]. Ref. [67] confirmed a decrease in organic matter (as BOD and total suspended solid) and nitrogen removal efficiency with a reduced hydraulic retention time because of less contact time of pollutants in the system. Ref. [72] recommended a 6-day hydraulic residence time for the acceptable level of treatment of COD, BOD, TN, and TP in horizontal subsurface flow CWs. However, the case studies reviewed here were conducted under different hydraulic retention times contributing to the observed difference in removal efficiencies.
Hydraulic loading rate, i.e., the quantity of wastewater supplied to the CWs system, affects the removal potentials. When there is a large increase in hydraulic load, the contact time between wastewater and biofilms is typically reduced, thus influencing the nitrogen and organics removal rates. According to [67], when hydraulic loading was increased from 31 mm/d to 146 mm/d, the mean organics and nitrogen removal efficiency decreased from 84% to 63%, and 84% to 16%, respectively. As there were different hydraulic loading rates utilized in the reviewed Italian cases, the pollutant removal potentials of the CWs have also resulted in various values.
The quantity of dissolved oxygen (DO) in the system has an impact on the nutrient removal process. According to [73], NO3−-N was eliminated at a lower DO concentration of 0.5 mg/L, while the removal rate decreased at higher DO concentrations. A total nitrogen (TN) elimination effectiveness of 70% was reported at DO levels of 0.15–0.2 mg/L [73]. In the reviewed works, both horizontal and vertical CWs were utilized, which have different levels of dissolved oxygen that directly control the microbial activities affecting the pollutant removal potentials. The substrate and wastewater feeding mode also affect the pollutant removal efficiency of CWs by enhancing oxygen transfer.
In this reviewed work, Phragmites australis, Typha latifolia, Arundo donax, and Cyperus alternifolius are the most frequently used plant species in the experiments treating various wastewaters. These experiments were conducted at different levels (laboratory, pilot, or large scale) depending on the area/volume of the CWs used. There were more pilot-scale studies than large-scale or laboratory-size studies. Similarly, the types of wastewater treated were also different; Urban/municipal/domestic wastewater being the most frequently treated ones, followed by effluent from wastewater treatment plants, agricultural wastewater, and swine/dairy wastewater. Horizontal subsurface CWs have been utilized more repeatedly than vertical and hybrid CW systems. Moreover, numerous contaminants were eliminated from various wastewaters utilizing CWs. COD (chemical oxygen demand), TN (total nitrogen), TSS (total suspended solids), BOD (biological oxygen demand), and TP (total phosphorus) were the major pollutants removed (based on their frequency) in the reviewed works.
Table
Table 1. Summary of research works performed on the application of constructed wetlands on wastewater treatment in Italy.
Table 1. Summary of research works performed on the application of constructed wetlands on wastewater treatment in Italy.
Type of CWsLocationResearch ScalePlants UsedWastewater TypePollutants and Removal Efficiency (RE %)Ref.
Combined (Lagoons and CWs)S. ItalypilotTypha latifoliaSwine wastewaterTSS and OM; (99%), TN; (80–95%)[74]
Surface flowN. E. ItalypilotPhragmites australis, Typha latifoliaAgricultural drainage TN; (58 kg/ha discharged out), TN input was 526 kg/ha[75]
HF and VFE. SicilypilotPhragmites sp.Municipal effluentsTSS; (85%), BOD5; (65%), COD; (75%), TN; (42%) and TP; (32%)[76]
HSS S. ItalypilotPhragmites australisDairy wastewater and domestic sewageCOD; (91.9%), BOD5; (93.7%), TN; (48%), TP; (60.6%), Nitrates;-Low conc., Chlorides; (48.7%), Sulfates; (87.8%), Cd; (23.7%), Cr; (51.6%), Cu; (79.4%), Ni; (58.6%), Pb; (69.6%), Zn; (85.7%), Total coliforms; (99.6%), E. coli; (99.7%), Faecal streptococci; (98.8%)[77]
TanksN. E. ItalypilotPhragmites australisPerfluoroalkyl acids 50% reduction in PFAAs [78]
HSSS. ItalypilotPhragmites australis, Typha latifoliaBenzene solutionBenzene; (39.78%) for the Phragmites field and (35.14%) for the Typha field[63]
Hybrid (HF and VF)C. ItalylargePhragmites australisDomestic wastewater COD; (83–95%), TSS; (68–93%), NH4+; (78–98%), pathogen elimination (3–5 logs)[79]
CWN. C. ItalylabPhragmites australisUrban and industrial wastewater Fe; (95%), Zn; (73%), Cu; (61%) (with batch experiment), and Cu; (46–80%), Fe; (70–100%), Zn; (65–85%) (with column system)[80]
HSSS. Italy pilotVetiveria zizanoides, Miscanthus x giganteus, Arundo donax, Phragmites australisWastewater from the treatment plantTSS; COD; NH4+; TN; PO4; and E.coli, respectively, by; Vetiveria zizanoides; (86%), (62%), (51%), (59%), (25%), (2.7%): Myscanthus x giganteus; (86%), (61%), (52%), (57%), (20%), (2.8%)
Arundo donax; (89%), (59%), (53%), (56%), (28%), (2.8%): Phragmites australis; (88%), (63%), (57%), (61%), (29%), (3.1%)		[81]
Hybrid (HF and VF)N. ItalypilotAster tripolium L. Juncus maritimus Lam., Typha latifoliaAgricultural effluent (anaerobic digester)COD; (76%), nitrate; (86%), ammonia; (87%), P; (87%) with 50 L/d inlet flow
COD; (88%), nitrate; (73%), ammonia; (98%), P; (99%) with 200 L/d inlet flow		[82]
VSSW. SicilypilotPhragmites australis, Arundo donaxFirst-flush stormwaterBOD5; (75–83%), COD; (65–69%), TN; (60–66%), Cu; (25–66%), Zn; (38–63%), E. coli; concentration levels < 100 (CFU 100 mL−1)[83]
HSSE. SicilylargePhragmites australis, Typha latifoliaUrban wastewater TSS; BOD5; COD; TN; NH4+; and TP; in CW1, CW2, and CW3, respectively; CW1; (77%), (62%), (63%), (48%), (42%), (25%): CW2; (80%), (63%), (66%),(44%), (40%), (24%): CW3; (81%), (61%), (59%), (44%), (39%), (20%)[84]
VSS, free water systemN. ItalylargePhragmites australisCombined sewer overflowCOD; (87%), NH4+ (93%)[85]
Hybrid (HF and VF)C. ItalylargePhragmites australisMixed (grey/black) wastewater COD; (94%), BOD5; (95%), TSS; (84%), NH4+; (86%), TN; (60%), TP; (94%), Total coliforms; faecal coliforms; faecal streptococci; and E. coli; ranged (99.93–99.99%)[86]
VF and HFN. ItalypilotJuncus maritimus, Typha latifolia, Cyperus papyrusIndustrial wastewaterThe RE in Inlet, VSS flow A, VSS flow B, and HSS flow, respectively, for;
COD; (18 ± 2%), (15 ± 1%), (14 ± 1%), (7 ± 1%): Zn; (418 ± 1%), (64.1 ± 9.5%), (112 ± 10%), (87.3 ± 9.5%)
Fe; (348.09 ± 25.476%), (13.5 ± 19.0%), (24.9 ± 19.0%), (6.53 ± 18.98%): NO3− (18.9 ± 1.0%), (17.9 ± 0.8%), (17.6 ± 0.83%), (48 ± 0.76%)		[87]
HSS S. Italy large---Dairy wastewater COD; (94.3%)[88]
HSS C. ItalylargePhragmites australisAgro-industrial wastewater COD; (93%), TSS; (81%), Ammonium; (55%), Nitrates; (40%) TP; (20%), TN; (0.3%), total coliforms; (99.1%), faecal coliforms; (99.7%), faecal streptococci; (99.8%), E. Coli.; (99.7%)[89]
VF and HF N. C. ItalypilotPhragmites australisLandfill leachatesCOD; reduction range (0–30%), ammonia; (50–80%), nitrite; (20–26%)[90]
HSS N. C. ItalylargePhragmites australisActivated sludge effluentRemovals of hexavalent/trivalent chromium; (72%) and (26%), respectively.[91]
HSS S. Italy pilotCyperus papyrus, Vetiveria zizanoides, Miscanthus x giganteus, Arundo donax, Phragmites australismunicipal wastewaterTSS; COD; and E. coli.; ranged (82–88%), (60–64%), and (2.7–3.1%) U log, respectively. TN; (64%), NH4-N; (61%), PO4-P; (31%)[92]
HSS S. ItalypilotCyperus alternifolius L., Typha latifolia Treated urban wastewaterTypha latifolia-based RE of TSS; BOD5; COD; TKN; N-NH4; TP; (64.3%), (72.4%), (75.7%), (51.6%), (49.6%), (47.9%): C. alternifolius based RE of TSS; BOD5; COD; TKN; N-NH4; TP; (47%), (64.8%), (66.6%), (36.1%), (38.3%), (31.7%), respectively. E. coli; RE did not exceed (89.5%)[93]
HSS S. ItalylargePhragmites australis, TyphaTreatment plant effluentTSS; BOD5; COD; TN; in (H-SSF) CW2; (74 ± 12%), (64 ± 15%), (67 ± 19%), (51± 26%): (H-SSF) CW3; (79 ± 10%), (58 ± 19%), (58 ± 19%), (42 ± 17%): (H-SSF) CW4; (74 ± 13%), (54 ± 23%), (57 ± 20%), (44 ± 23%): Ammonia removal (51%) for H-SSF2, (42%) for H-SSF3 and (44%) for H-SSF4[94]
Constructed surface flow N. E. ItalylargePhragmites australis, Typha latifoliaAgricultural drainage N; (90%)[95]
FRB, VF, free water C. ItalypilotPhragmites australisTreatment plant wastewaterCOD; BOD5; TN; N-NH4+; TP; and TSS; were (>80%)[96]
Wall cascade (WC) N.E. ItalypilotMentha aquatica L., Oenanthe javanica, Lysimachia nummularia L. Kitchen grey watersCOD; (86%), BOD5; (83%), MBAS; (anionic surfactants) (82%), TKN; (57%) and N-NH4; (43%)[97]
Hybrid (VF and HF) --pilotAster tripoloium, Typha latifoliaArtificially grey waterCOD; (95%) (inside the V-SSF vegetated tank)[98]
HF and VF S. ItalypilotPhragmites australiswastewater treatment plant effluent TSS; (>85%), BOD5; (74%), COD; (61%), TN; (54%), Nitrate; (87%), TP; (57%) in Phragmites australis covered beds. Faecal coliforms; E. coli; and faecal streptococci; (>97%) [99]
HFS. ItalypilotArundo donax L., Cyperus alternifolius L. Urban wastewater BOD5; (70–72%), COD; (61–67%), TKN; (47–50%), TP; (43–45%), Pathogen; load removal (90%)[100]
HF --labPhragmites australis, Carex oshimensis, Cyperus papyrusGrey waterTurbidity; (>92%), TSS; (>85%), COD; (>89%), BOD5; (>88%)[101]
HF (H-SSF1 and H-SSF2) S. ItalylargePhragmites australisTreatment plant effluentTSS; COD; BOD; (80%), (63%), (58%) for H-SSF1 and (67%), (38%), (41%) for H-SSF2[102]
Hybrid (HF and VF) S. ItalylargePhragmites australis, Iris pseudacorus, Cyperus papyrus var. siculus, Canna indica, Typha latifoliaEffluent from a tertiary treatment unitTSS; (95.8 ± 1.4%), BOD5; (93.2 ± 3.6%), COD; (92.7 ± 6.8%), TP; as PO4 (P-PO4) (26.7 ± 11.2%), N; as NH4 (N-NH4) (78.2 ± 30.8%), TN; (55.1 ± 7.1%), N; as NO3 (N-NO3) (20.7 ± 8.3%), E. coli; (CFU/100 mL) (4 ± 0.7%)[103]
CWS. C. ItalylargeIris pseudacorus, Juncus effusus, Carex elata, Nymphaea albaDomestic sewage COD; (7.6%), TSS; (6.7%), N-NH4+; (92.3%), NO3−; (63.3%), E. coli; (96.2%)[104]
Hybrid S. W. ItalypilotPhragmites australis, Arundo donax, Arundo plinii TurraLandfill leachateCOD; (93%), BOD5; (95%) Ni; (92%)[105]
Surface flow N. C. ItalylargePhragmites australis, Typha latifolia, Typha angustifolia, Salix alba, Populus albaAgricultural drainage TN; (47%), TP (49%)[106]
Hybrid S. ItalypilotCanna indica, Typha latifoliaSemi-synthetic stormwaterMetals; (Cd, Cr, Fe, Pb, Cu, Zn) (70–98%)[107]
Constructed surface flow N. E. ItalylargePhragmites australisHerbicide runoff Mitigation effectiveness (98%), i.e., (45–80%) fold lower than the applied concentration [108]
Hybrid (VF and HF) N. W.
Italy		pilotPhragmites australisCheese factory wastewaterRE (minimum-maximum) for TSS; (28–88%), COD; (53–80%), BOD5; (31–80%), TOC; (25–80%), TP; (10–73%), TN; (40–51%)[109]
Subsurface flow N. W. ItalylargePhragmites australis, Typha latifolia, Scirpus lacustrisDairy wastewaterBOD5; (>90%), nitrogen (50–60%)[110]
(HF and VFl), and free water systemC. Italylarge16 different Tuscany’s native macrophytesMunicipal wastewaterOrganic load; (86%), TN; (60%), TP; (43%), TSS; (89%), (NH4+); (76%), (4–5) logs pathogens concentration [111]
Surface flow N. E. ItalylargeTypha latifolia, Phragmites australisAgricultural drainage NO3–N; (83%), TN; (79%), PO4-P; (48%), TP; (67%)[112]
Free water surface N. E. ItalylargePhragmites australis, Typha latifolia, Carex spp., Juncus spp., Phalaris arundinacea, Mentha aquatic, Iris pseudacorus Agricultural drainage watersTN; (33.3–49.0%), N-NO3; (32.2–80.5%)[113]
HSS C. ItalypilotPhragmites australisOlive oil extraction effluentCOD; (74.1 ± 17.6%), polyphenols (83.4 ± 17.8%)[114]
HSS, and free water systemC. ItalylargeTypha latifolia, Myriophyllum spicatum, Phragmites australis, Elodea Canadensis, Ceratophyllum demersum, Lythrum salicaria, Iris pseudacorus, Epilobium hirsutum, Alisma plantago aquatica, Butumus umbellatusWinery wastewaterCOD; (97.5%), N-NO2−; (84.7%), NO3−; (39.9%), TP; (45.5%)[115]
Subsurface VF C. ItalypilotZantedeschia aethiopica, Canna indica, Carex hirta, Miscanthus sinensis, Phragmites australisSynthetic wastewater (micropollutant)N; (67.4%), P; (74.4%), Zn; (99.3%), Cu; (99.3%), LAS; (78.3%), Carbamazepine; (61.4%)[116]
HSS S. ItalypilotPhragmites australis, Typha latifoliaProduced wastewaterParacetamol removals in phragmites bed (51.7–99.9%), in Typha bed (46.7–>99.9%)[117]
Surface flow N. ItalylargePhragmites australis, Typha latifolia, Carex spp. Agricultural drainage waterTSS; (82%), TN; (78%), NO3-N; (78%), NH4+-N; (91%)[118]
Hybrid (VF and HF) N. E. Italy pilotCanna indica, Symphytum officinale, Phragmites australisPiggery wastewaterCOD; (79%), TN; (64%), NH4-N; (63%), NO3-N; (53%), P; (61%)[119]
HSS S. ItalypilotArundo donax, Cyperus alternifoliusPre-treated urban wastewater TSS; (73.72%), BOD; (67%), COD; (66.21%), TN; (50.33%), NH4-N; (54.11%), TP; (41.11%). Total coliforms; faecal coliforms; faecal streptococci; and E.coli; (89.60%), (88.01%), (83.12%), and (87.67%), respectively.[120]
V-SSF and H-SSFN. ItalypilotPhragmites australisDomestic wastewatersTN; (71%), NH4-N; (94%), TP; (27%) and COD; (92%) in the v-SSF
TN; (59%), NH4-N; (21%), TP; (52%) and COD; (70%) in the h-SSF		[121]
CWsC. Italy largePhragmites australis, Typha latifolia, Lemna minor L., Lemna minuta Kunth, Sparganium erectum L., Carex pendula Huds, Salix alba L., Populus alba L.Municipal wastewaterSulphates; (50%), (33% in winter)
Nitrates; (80%) in winter, (15%) in spring and summer
E. coli; (82%) in spring, (99%) in autumn		[122]
HSSS. ItalypilotCyperus alternifolius, Typha latifoliawastewater treatment plant effluentBOD5; (70.6–68.1%), TKN; (43.9–52.8%), N-NH4; (43.2–48.0%), TP; (37.8–42.1%), Total coliforms; (80.5–88.7%), Faecal coliforms; (83.5–90.6%), Faecal streptococci; (76.6–83.1%), E. coli; (87.3–91.3%)[123]
(H-SSF1) and
(H-SSF2)		N. E. Italy
S. Italy		largePhragmites australisPiggery manure
Municipal wastewater		COD; (62.7%), TN; (34.9%), TP; (7.61%)
COD; (64.5–45.1%), TN; (44.4–48.1%), TP; (25–37.5%) in Catania (S. Italy)		[124]
HSS N. ItalypilotPhragmites australisDomestic wastewaterCu; (3.4–9%), Ni; (35 ± 16–25 ± 10%), Zn; (27 ± 9–26 ± 5.4%)[125]
HSF S. ItalypilotPhragmites australis, Typha latifoliaBTEX and metals solutionFe; (88–95%), Cr; (86–90%), Pb; (78–88%): BTEX; (46–57%)[126]
HSS S. ItalylargePhragmites australismunicipal wastewater effluentTSS; BOD5; COD; TN; and TP; (74 ± 16%), (42 ± 21%), (41 ± 21%), (61 ± 17%), and (50 ± 31%), respectively.[127]
HSSS. ItalypilotPhragmites australis, Typha latifoliaArtificial wastewaterCr; (87%), Pb; (88%), Fe; (92%) in Phragmites bed: Cr; (90%), Pb; (87%), Fe; (95%) in Typha bed[128]
CWC. ItalypilotPhragmites australis, Salix matsudanaUrban wastewater
(micro-pollutants)		NP; diclofenac; atenolol; (8.4–100%) in P. australis bed
while S. matsudana preferentially removed NP1EO, NP2EO, ketoprofene, and triclosan		[129]
HSS N. Italy pilotPhragmites australismunicipal (micro-pollutant)From 1% for psychiatric drugs to 26% for antihypertensives, on average (16 ± 8%)[130]
HSSFs CW(1)
HSSFs CW(2)		S. ItalypilotFestuca, Lolium, Pennisetum spp., Arundo donax L., Cyperus alternifolius L., Typha latifolia L. Treated wastewaterRE by T. latifolia and C. alternifolius for TSS; (64–57%), BOD5; (68–64%), COD; (75–70%), TKN; (51–43%), NH4-N; (52–41%), TP; (47–38%), Total Coliform; (88–85%), Faecal Coliform; (88–83), Faecal Streptococci; (84–77%), E.coli; (90–88%)
RE by A. donax and C. alternifolius for TSS; (74–71%), BOD5; (70–64%), COD; (71–66%), TKN; (48–45%), TP; (48–42%), Total coliforms; (89–85%), Faecal coliforms; (90–88%), E. coli; (88–85%)		[131]
HSS S. ItalypilotCyperus alternifolius, Typha latifoliaUrban wastewaterRE by C. alternifolius and T. latifolia for TSS; (74.2–77%), BOD; (68–70.5%), COD; (74.2–77%), TKN; (42.7–51.8%), N-NH4; (42.3–49.4%), TP; (35.6–39%). Total coliforms; (83.6–90.4%), Faecal coliforms; (79.6–88.8%), Faecal streptococci; (76.4–84.1%), E. coli; (87.7–92.1%)[132]
HSS S. ItalypilotArundo donax, Cyperus alternifoliusDairy wastewaterRE by A. donax and C. alternifolius for TSS; (79.6–76.1%), BOD5; (61.8–61.4%), COD; (51.5–53.1%), TN; (45.2–41.7%), N-NH4; (36.7–40.7%), ON; (41.8–41.1%), TP; (49.8–45.7%), Cu; (43.2–39.9%), Ni; (44.7–39.3%), Pb; (58.3–46.3%), Zn; (--/--), Total coliforms; (88.1–83.2%), Faecal streptococci; (83.9–81.3%), E. coli; (88.3–86.9%), Salmonella spp; (--/--)[133]
CWsN. ItalylargePhragmites australisRiver water (heavy metals)Cr; (36.96 mg/g), Ni; (0.67–2.4 mg/g) but 10 times higher in December[134]
HSS S. ItalylargePhragmites sp. wastewater treatment plant effluentTSS; (77–92%), BOD5; (37–72%), COD; (51–79%), E. coli; (97–99.5%). Salmonella; and helminth; eggs 100% removed[135]
Hybrid (VF and HF) N. E. ItalylargeCanna indica, Phragmites australisSynthetic wastewaterTN; (95%), NH4-N; (95%), NO3-N; (93%)[136]
Hybrid (VF and HF)N. ItalypilotPhragmites australisUniversity wastewaterRE by vertical-horizontal CWs for COD; (70.4–40.1%), TSS; (80.4–72.7%), TN; (49.3–88.8%), NO3—N; (--/--), NO2–N; (--/--), TP; (47.3%-88.5%), PO43−P (34.2–95.1%), Cl−; (0–9.7%), Br−; (33%/-), SO42−; (3.5–10.2%). E. coli; (74.7–99.7%), Total coliforms; (90.7–93.5%), Enterococcus; (50.1–99.9%)[137]
HSS S. ItalypilotArundo donax, Cyperus alternifoliusTreated urban wastewater RE by A. donax and C. alternifolius for TSS; (69.5–64.5%), BOD5; (57.1–54.2%), COD; (72.9–72%, TKN; (54–51.9%), N-NH4; (59.7–57.5%), TP; (35.1–36.4%), Cl; (8.8–8.6%), Ca; (28–26%), K; (26.3–21%), Mg; (16.4–11.5%), Na; (9.9–7%)[138]
HSSN. C. ItalylargePhragmites australisTextile wastewater Hexavalent chromium; (70%)[139]
HSS S. ItalypilotArundo donax, Cyperus alternifoliusCombined dairy and domestic wastewaterRE by A. donax and C. alternifolius for TSS; (80.69–82.98%), BOD5; (78.02–75.61%), COD; (62.67–61.12%), TN; (51.84–49.68%), N–NH4; (45.05–51.51%), ON; (40.51–45.11%), TP; (39.86–38.88%), Cu; (44.11–48.31%), Ni; (35.17–31.03%), Pb; (31.57–36.84%), Zn; (56.25–50.33%)[140]
VF S. E. ItalypilotPhragmites australisA mix of 5%, 10%, and 20% landfill leachateCOD; (60.5%), N–NH4+; (47.5%) in 5% landfill leachate.
N-NO3–; (49.4%) in 10% of landfill leachate		[141]
VSS, HSS, and free surface flow S. ItalylargePhragmites australis, Cyperus Papyrus var. Siculus, Canna indica, Iris pseudacorus, Nymphaea alba L., Scirpus lacustris L.Winery wastewaterTSS; (69%), BOD5; (78%), COD; (81%), NH4-N; (57%), TN; (56%), PO4-P; (38%)[142]
Hybrid (SSF and floating) E. ItalylargeArundo donax, Phragmites australisDigestate liquid fraction from anaerobic digestion plantCOD; (57.9%), TN; (64.6%), NH4-N; (65.1%), NO3-N; (35.6%), TP; (49.2%), PO4-P; (45.1%) in the subsurface flow line and, COD; (89.2%), TN; (90%), NH4-N; (89%), NO3-N; (93.8%), TP; (50.3%), PO4-P; (49.9%) in floating treatment wetland line[143]
Hybrid (HSS and floating) N. E. Italy pilotPhragmites australis, Iris pseudacorusMunicipal wastewaterTN; (74.3%), NH4-N; (62.1%), NO3-N; (77.7%), TP; (29.6%), PO4-P; (37.4%), COD; (46.7%)[144]
Plastic vertical in-vessel S. Italy pilotArundo donaxMunicipal sewage COD; (78.7–85.7%), TSS; (89–94.9%), TN; (86.1–93.2%), ammonia; (77.4–98.1%). Cu; and Zn; reduced almost to zero[145]
Microcosm SSN. E. ItalylargeCarex elata, Juncus effusus L., Phalaris arundinacea, Phragmites australis, Typha latifolia L.Artificial wastewaterPO4-P; removal (86.2%), (48.1%), (37.6%) and (36.0%) for P. aundinacea, C. elata, J. effusus and P. australis bed, respectively. T. latifolia was able to remove more than the PO4-P load (13.05 g/m2), with a P uptake: P supplied ratio (21.8%)[146]
HSS N. E. ItalypilotTypha angustifolia, Phragmites australisDomestic wastewater Pathogens (98%). TSS; COD; and, BOD5 (90%). N-NH4+; N-NO3–; TN; Cl–; SO42–;PO43– (50%)[147]
HSS S. ItalypilotCyperus alternifolius, Typha latifoliaUrban wastewater BOD5; calculated using concentrations and mass loads in T. latifolia (65.5 ± 7.4%) and (70.7 ± 3.8%), respectively. For C. alternifolius (60.5 ± 8.9%) and (65.5 ± 5.5%)[148]
Note: BOD5—biochemical oxygen demand of 5 days; Br—bromine; BTEX—benzene; toluene; ethylbenzene and xylene; Ca—calcium; Cd—cadmium; CFU—colony forming units; Cl—chlorine; COD—chemical oxygen demand; Cr—chromium; Cu—copper; CWs—constructed wetlands; E. Coli.—Escherichia Coli; Fe—iron; FRB—French reed bed; HF—horizontal flow; HSF—horizontal surface flow; HSS—horizontal sub-surface; K—potassium; LAS—linear alkylbenzene sulfonate; MBAS—methylene blue active substance; Mg—magnesium; Na—sodium; NH4+—ammonium; NH4−N—nitrogen level in ammonium ion; Ni—nickel; N—nitrogen; N-NO2−—nitrogen in nitrite; NO3−—nitrate; NP1EO—monoethoxylated nonylphenol; NP2EO—diethoxylated nonylphenol; NP—nonylphenol; OM—organic matter; Pb—lead; PFAAS—perfluoroalkyl acids; PO43−—phosphate as P; PO4—phosphate; P—phosphorus; RE—removal efficiency; SO42−sulphate; TKN—total Kjeldahl nitrogen; TN—total nitrogen; TOC—total organic carbon; TP—total phosphorus; TSSs—total suspended solids; U log—log units; VF—vertical flow; VSS—vertical sub-surface; Zn—zinc.
The pollutant removal efficiencies of the hybrid CWs in the reviewed case studies were very high compared to the other types of CWs, which are similar to research results reported elsewhere [24,32,45]. The removal efficiency of COD ranged from 53% to 80%, but the highest values (79–97.5%) were obtained in trials with hybrid CWs, which is in line with a recent work that achieved a COD removal of 97.56 ± 1.6% [149]. Similarly, removal efficiency for TN of the reviewed work was between 60% and 66%; however, hybrid CWs managed to increase the performance (64–88%). This result is in agreement with the work of [150], who reported 82.71 ± 3.92% TN removal in an anoxic-aerobic system combined with an integrated vertical-flow constructed wetland.
The removal efficiency of TSS was also very high (89% to 95%), indicating the potential of CWs. This result is supported by the range of values (81.6–97.1%) for TSS removal from anaerobic reactor brewery effluent reported by [151]. Moreover, CWs were able to remove BOD successfully (75–80%), but then again the highest values (93–95%) were recorded in experiments conducted with hybrid CWs. These values are also consistent with reported BOD removal that ranged between 85% and 94% [152]. Even though the removal efficiency for TP was relatively low (10–73%), hybrid CWs gave higher values (47–94%), which is also comparable with the removal percentage (92.28 ± 2.78%) reported by [150].
Heavy metals (Zn, Cu, Pb, Ni) and pathogens (total coliforms, faecal streptococci, E.coli.) were also removed in some of the experiments conducted with CWs. For instance, the removal efficiency of Zinc ranged between 65% and 85%; nonetheless, the hybrid CWs resulted in high performances (70–98%). A total reduction in zinc and copper almost closer to zero was also reported [145]. The lead removal efficiency was 78–88%. The hybrid CWs again resulted in high removal potentials (70–98%). The removal efficiency for nickel was between 35 and 58%, but hybrid CWs, in the same way, gave a high value (92%). Removal efficiency for copper ranged from 46 to 80%, then again a removal potential of 99.3% was obtained with hybrid CWs.

4. Conclusions and Future Directions

This article reviewed 76 published results that engage CWs in treating several wastewaters. The experiments were conducted at various times and places, employing different operational parameters. However, it has been attempted to consider and tabulate only the operational parameters reported in all the reviewed works. The number of research outputs published showed an increasing trend over time (23 years), in a way indicating the research progress of the application of CWs in wastewater treatment. The performance of the reviewed works of CWs in treating wastewater in Italy varied considerably because of many biotic and abiotic factors affecting the major biological, physical, and chemical activities going on in the CWs. However, all assessed works of CWs in treating wastewater are considered the best at removing pollutants. The knowledge and skills acquired from these results could be utilized as a foundation for any planned nature-based wastewater treatment activities. It is also worthwhile doing additional large-scale trials to confirm the capability of CWs in eliminating pollutants from wastewater because there is a chance that they will provide different findings from those found in pilot-scale studies.

Author Contributions

Conceptualization, B.R., E.C. and C.C.; methodology, B.R., E.C. and C.C.; data curation, B.R.; writing—original draft preparation, B.R., E.C., C.C. and E.G.; writing—review and editing, B.R. and E.G. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Chheang, L.; Thongkon, N.; Sriwiriyarat, T.; Thanasupsin, S.P. Heavy Metal Contamination and Human Health Implications in the Chan Thnal Reservoir, Cambodia. Sustainability 2021, 13, 13538. [Google Scholar] [CrossRef]
  2. Schoumans, O.F.; Chardon, W.J.; Bechmann, M.E.; Gascuel-Odoux, C.; Hofman, G.; Kronvang, B.; Rubæk, G.H.; Ulén, B.; Dorioz, J.-M. Mitigation Options to Reduce Phosphorus Losses from the Agricultural Sector and Improve Surface Water Quality: A Review. Sci. Total Environ. 2014, 468–469, 1255–1266. [Google Scholar] [CrossRef]
  3. Resende, J.D.; Nolasco, M.A.; Pacca, S.A. Life Cycle Assessment and Costing of Wastewater Treatment Systems Coupled to Constructed Wetlands. Resour. Conserv. Recycl. 2019, 148, 170–177. [Google Scholar] [CrossRef]
  4. Marañón, E.; Ulmanu, M.; Fernández, Y.; Anger, I.; Castrillón, L. Removal of Ammonium from Aqueous Solutions with Volcanic Tuff. J. Hazard. Mater. 2006, 137, 1402–1409. [Google Scholar] [CrossRef]
  5. Biggs, J.; von Fumetti, S.; Kelly-Quinn, M. The Importance of Small Waterbodies for Biodiversity and Ecosystem Services: Implications for Policy Makers. Hydrobiologia 2017, 793, 3–39. [Google Scholar] [CrossRef]
  6. Gasco Cavero, S.; García-Gil, A.; Cruz-Pérez, N.; Martín Rodríguez, L.F.; Laspidou, C.; ContrerasLlin, A.; Quintana, G.; Díaz-Cruz, S.; Santamarta, J.C. First Emerging Pollutants Profile in Groundwater of the Volcanic Active Island of El Hierro (Canary Islands). Sci. Total Environ. 2023, 872, 162204. [Google Scholar] [CrossRef] [PubMed]
  7. Obaideen, K.; Shehata, N.; Sayed, E.T.; Abdelkareem, M.A.; Mahmoud, M.S.; Olabi, A.G. The Role of Wastewater Treatment in Achieving Sustainable Development Goals (SDGs) and Sustainability Guideline. Energy Nexus 2022, 7, 100112. [Google Scholar] [CrossRef]
  8. Castellar, J.A.C.; Torrens, A.; Buttiglieri, G.; Monclús, H.; Arias, C.A.; Carvalho, P.N.; Galvao, A.; Comas, J. Nature-Based Solutions Coupled with Advanced Technologies: An Opportunity for Decentralized Water Reuse in Cities. J. Clean. Prod. 2022, 340, 130660. [Google Scholar] [CrossRef]
  9. Zhang, B.Y.; Zheng, J.S.; Sharp, R.G. Phytoremediation in Engineered Wetlands: Mechanisms and Applications. Procedia Environ. Sci. 2010, 2, 1315–1325. [Google Scholar] [CrossRef]
  10. Mahar, A.; Wang, P.; Ali, A.; Awasthi, M.K.; Lahori, A.H.; Wang, Q.; Li, R.; Zhang, Z. Challenges and Opportunities in the Phytoremediation of Heavy Metals Contaminated Soils: A Review. Ecotoxicol. Environ. Saf. 2016, 126, 111–121. [Google Scholar] [CrossRef]
  11. Mustafa, H.M.; Hayder, G. Recent Studies on Applications of Aquatic Weed Plants in Phytoremediation of Wastewater: A Review Article. Ain Shams Eng. J. 2021, 12, 355–365. [Google Scholar] [CrossRef]
  12. Vymazal, J. Constructed Wetlands for Wastewater Treatment. Water 2010, 2, 530–549. [Google Scholar] [CrossRef]
  13. Saeed, T.; Sun, G. A Review on Nitrogen and Organics Removal Mechanisms in Subsurface Flow Constructed Wetlands: Dependency on Environmental Parameters, Operating Conditions and Supporting Media. J. Environ. Manag. 2012, 112, 429–448. [Google Scholar] [CrossRef] [PubMed]
  14. Almeida, C.M.R.; Santos, F.; Ferreira, A.C.F.; Lourinha, I.; Basto, M.C.P.; Mucha, A.P. Can Veterinary Antibiotics Affect Constructed Wetlands Performance during Treatment of Livestock Wastewater? Ecol. Eng. 2017, 102, 583–588. [Google Scholar] [CrossRef]
  15. Zhang, D.; Gersberg, R.M.; Ng, W.J.; Tan, S.K. Removal of Pharmaceuticals and Personal Care Products in Aquatic Plant-Based Systems: A Review. Environ. Pollut. 2014, 184, 620–639. [Google Scholar] [CrossRef]
  16. Schwitzguébel, J.-P.; Comino, E.; Plata, N.; Khalvati, M. Is Phytoremediation a Sustainable and Reliable Approach to Clean-up Contaminated Water and Soil in Alpine Areas? Environ. Sci. Pollut. Res. 2011, 18, 842–856. [Google Scholar] [CrossRef]
  17. Kamilya, T.; Majumder, A.; Yadav, M.K.; Ayoob, S.; Tripathy, S.; Gupta, A.K. Nutrient Pollution and Its Remediation Using Constructed Wetlands: Insights into Removal and Recovery Mechanisms, Modifications and Sustainable Aspects. J. Environ. Chem. Eng. 2022, 10, 107444. [Google Scholar] [CrossRef]
  18. Bruch, I.; Fritsche, J.; Bänninger, D.; Alewell, U.; Sendelov, M.; Hürlimann, H.; Hasselbach, R.; Alewell, C. Improving the Treatment Efficiency of Constructed Wetlands with Zeolite-Containing Filter Sands. Bioresour. Technol. 2011, 102, 937–941. [Google Scholar] [CrossRef]
  19. Klomjek, P. Swine Wastewater Treatment Using Vertical Subsurface Flow Constructed Wetland Planted with Napier Grass. Sustain. Environ. Res. 2016, 26, 217–223. [Google Scholar] [CrossRef]
  20. Moreira, F.D.; Dias, E.H.O. Constructed Wetlands Applied in Rural Sanitation: A Review. Environ. Res. 2020, 190, 110016. [Google Scholar] [CrossRef]
  21. Dan, T.H.; Quang, L.N.; Chiem, N.H.; Brix, H. Treatment of High-Strength Wastewater in Tropical Constructed Wetlands Planted with Sesbania Sesban: Horizontal Subsurface Flow versus Vertical Downflow. Ecol. Eng. 2011, 37, 711–720. [Google Scholar] [CrossRef]
  22. Vymazal, J. Plants Used in Constructed Wetlands with Horizontal Subsurface Flow: A Review. Hydrobiologia 2011, 674, 133–156. [Google Scholar] [CrossRef]
  23. Rajan, R.J.; Sudarsan, J.S.; Nithiyanantham, S. Efficiency of Constructed Wetlands in Treating E. Efficiency of Constructed Wetlands in Treating E. Coli Bacteria Present in Livestock Wastewater. Int. J. Environ. Sci. Technol. 2020, 17, 2153–2162. [Google Scholar] [CrossRef]
  24. Vymazal, J. Constructed Wetlands for Treatment of Industrial Wastewaters: A Review. Ecol. Eng. 2014, 73, 724–751. [Google Scholar] [CrossRef]
  25. Wang, M.; Zhang, D.; Dong, J.; Tan, S.K. Application of Constructed Wetlands for Treating Agricultural Runoff and Agro-Industrial Wastewater: A Review. Hydrobiologia 2018, 805, 1–31. [Google Scholar] [CrossRef]
  26. Fountoulakis, M.S.; Terzakis, S.; Chatzinotas, A.; Brix, H.; Kalogerakis, N.; Manios, T. Pilot-Scale Comparison of Constructed Wetlands Operated under High Hydraulic Loading Rates and Attached Biofilm Reactors for Domestic Wastewater Treatment. Sci. Total Environ. 2009, 407, 2996–3003. [Google Scholar] [CrossRef] [PubMed]
  27. Chang, J.; Deng, S.; Li, X.; Li, Y.; Chen, J.; Duan, C. Effective Treatment of Acid Mine Drainage by Constructed Wetland Column: Coupling Walnut Shell and Its Biochar Product as the Substrates. J. Water Process Eng. 2022, 49, 103116. [Google Scholar] [CrossRef]
  28. Huett, D.O.; Morris, S.G.; Smith, G.; Hunt, N. Nitrogen and Phosphorus Removal from Plant Nursery Runoff in Vegetated and Unvegetated Subsurface Flow Wetlands. Water Res. 2005, 39, 3259–3272. [Google Scholar] [CrossRef]
  29. Bulc, T.G. Long Term Performance of a Constructed Wetland for Landfill Leachate Treatment. Ecol. Eng. 2006, 26, 365–374. [Google Scholar] [CrossRef]
  30. Markou, G.; Wang, L.; Ye, J.; Unc, A. Using Agro-Industrial Wastes for the Cultivation of Microalgae and Duckweeds: Contamination Risks and Biomass Safety Concerns. Biotechnol. Adv. 2018, 36, 1238–1254. [Google Scholar] [CrossRef]
  31. Saeed, T.; Sun, G. A Comparative Study on the Removal of Nutrients and Organic Matter in Wetland Reactors Employing Organic Media. Chem. Eng. J. 2011, 171, 439–447. [Google Scholar] [CrossRef]
  32. Wu, S.; Kuschk, P.; Brix, H.; Vymazal, J.; Dong, R. Development of Constructed Wetlands in Performance Intensifications for Wastewater Treatment: A Nitrogen and Organic Matter Targeted Review. Water Res. 2014, 57, 40–55. [Google Scholar] [CrossRef] [PubMed]
  33. Almuktar, S.A.A.A.N.; Abed, S.N.; Scholz, M. Wetlands for Wastewater Treatment and Subsequent Recycling of Treated Effluent: A Review. Environ. Sci. Pollut. Res. 2018, 25, 23595–23623. [Google Scholar] [CrossRef] [PubMed]
  34. USEPA. A Handbook of Constructed Wetlands: A Guide to Creating Wetlands for Agricultural Wastewater, Domestic Wastewater, Coal Mine Drainage Stormwater in the Mid-Atlantic Region; Vol. 1: General considerations; United States Environmental Protection Agency (USEPA): Washington, DC, USA, 2000.
  35. Kadlec, R.H.; Wallace, S.D. Treatment Wetlands, 2nd ed.; CRC Press: Boca Raton, FL, USA, 2009; ISBN 978-1-56670-526-4. [Google Scholar]
  36. Nivala, J.; Wallace, S.; Headley, T.; Kassa, K.; Brix, H.; van Afferden, M.; Müller, R. Oxygen Transfer and Consumption in Subsurface Flow Treatment Wetlands. Ecol. Eng. 2013, 61, 544–554. [Google Scholar] [CrossRef]
  37. Vymazal, J.; Kröpfelová, L. Wastewater Treatment in Constructed Wetlands with Horizontal SubSurface Flow; Environmental Pollution; Springer: Dordrecht, The Netherlands, 2008; Volume 14, ISBN 978-1-4020-8579-6. [Google Scholar]
  38. Tsihrintzis, V.A.; Akratos, C.S.; Gikas, G.D.; Karamouzis, D.; Angelakis, A.N. Performance and Cost Comparison of a FWS and a VSF Constructed Wetland System. Environ. Technol. 2007, 28, 621–628. [Google Scholar] [CrossRef]
  39. Vymazal, J. Removal of Nutrients in Various Types of Constructed Wetlands. Sci. Total Environ. 2007, 380, 48–65. [Google Scholar] [CrossRef]
  40. Eke, P.E.; Scholz, M. Benzene Removal with Vertical-Flow Constructed Treatment Wetlands. J. Chem. Technol. Biotechnol. 2008, 83, 55–63. [Google Scholar] [CrossRef]
  41. Zhao, Y.Q.; Sun, G.; Allen, S.J. Anti-Sized Reed Bed System for Animal Wastewater Treatment: A Comparative Study. Water Res. 2004, 38, 2907–2917. [Google Scholar] [CrossRef]
  42. Zhi, W.; Yuan, L.; Ji, G.; He, C. Enhanced Long-Term Nitrogen Removal and Its Quantitative Molecular Mechanism in Tidal Flow Constructed Wetlands. Environ. Sci. Technol. 2015, 49, 4575–4583. [Google Scholar] [CrossRef]
  43. Sani, A.; Scholz, M.; Bouillon, L. Seasonal Assessment of Experimental Vertical-Flow Constructed Wetlands Treating Domestic Wastewater. Bioresour. Technol. 2013, 147, 585–596. [Google Scholar] [CrossRef]
  44. Vymazal, J. The Use of Hybrid Constructed Wetlands for Wastewater Treatment with Special Attention to Nitrogen Removal: A Review of a Recent Development. Water Res. 2013, 47, 4795–4811. [Google Scholar] [CrossRef] [PubMed]
  45. Vymazal, J. Emergent Plants Used in Free Water Surface Constructed Wetlands: A Review. Ecol. Eng. 2013, 61, 582–592. [Google Scholar] [CrossRef]
  46. Kochi, L.Y.; Freitas, P.L.; Maranho, L.T.; Juneau, P.; Gomes, M.P. Aquatic Macrophytes in Constructed Wetlands: A Fight against Water Pollution. Sustainability 2020, 12, 9202. [Google Scholar] [CrossRef]
  47. Ali, H.; Khan, E.; Sajad, M.A. Phytoremediation of Heavy Metals—Concepts and Applications. Chemosphere 2013, 91, 869–881. [Google Scholar] [CrossRef]
  48. Ennabili, A.; Radoux, M. Nitrogen and Phosphorus Uptake and Biomass Production in Four Riparian Plants Grown in Subsurface Flow Constructed Wetlands for Urban Wastewater Treatment. J. Environ. Manag. 2021, 280, 111806. [Google Scholar] [CrossRef]
  49. Batool, A.; Saleh, T.A. Removal of Toxic Metals from Wastewater in Constructed Wetlands as a Green Technology; Catalyst Role of Substrates and Chelators. Ecotoxicol. Environ. Saf. 2020, 189, 109924. [Google Scholar] [CrossRef]
  50. Yang, Y.; Zhao, Y.; Liu, R.; Morgan, D. Global Development of Various Emerged Substrates Utilized in Constructed Wetlands. Bioresour. Technol. 2018, 261, 441–452. [Google Scholar] [CrossRef]
  51. Ji, Z.; Tang, W.; Pei, Y. Constructed Wetland Substrates: A Review on Development, Function Mechanisms, and Application in Contaminants Removal. Chemosphere 2022, 286, 131564. [Google Scholar] [CrossRef]
  52. Valipour, A.; Ahn, Y.-H. Constructed Wetlands as Sustainable Ecotechnologies in Decentralization Practices: A Review. Environ. Sci. Pollut. Res. 2016, 23, 180–197. [Google Scholar] [CrossRef]
  53. Dordio, A.V.; Carvalho, A.J.P. Organic Xenobiotics Removal in Constructed Wetlands, with Emphasis on the Importance of the Support Matrix. J. Hazard. Mater. 2013, 252–253, 272–292. [Google Scholar] [CrossRef]
  54. Ge, Y.; Wang, X.; Zheng, Y.; Dzakpasu, M.; Zhao, Y.; Xiong, J. Functions of Slags and Gravels as Substrates in Large-Scale Demonstration Constructed Wetland Systems for Polluted River Water Treatment. Environ. Sci. Pollut. Res. 2015, 22, 12982–12991. [Google Scholar] [CrossRef] [PubMed]
  55. Ding, X.; Xue, Y.; Zhao, Y.; Xiao, W.; Liu, Y.; Liu, J. Effects of Different Covering Systems and Carbon Nitrogen Ratios on Nitrogen Removal in Surface Flow Constructed Wetlands. J. Clean. Prod. 2018, 172, 541–551. [Google Scholar] [CrossRef]
  56. Lu, S.; Hu, H.; Sun, Y.; Yang, J. Effect of Carbon Source on the Denitrification in Constructed Wetlands. J. Environ. Sci. 2009, 21, 1036–1043. [Google Scholar] [CrossRef] [PubMed]
  57. Chen, Z.-J.; Tian, Y.-H.; Zhang, Y.; Song, B.-R.; Li, H.-C.; Chen, Z.-H. Effects of Root Organic Exudates on Rhizosphere Microbes and Nutrient Removal in the Constructed Wetlands. Ecol. Eng. 2016, 92, 243–250. [Google Scholar] [CrossRef]
  58. Tao, W.; He, Y.; Wang, Z.; Smith, R.; Shayya, W.; Pei, Y. Effects of PH and Temperature on Coupling Nitritation and Anammox in Biofilters Treating Dairy Wastewater. Ecol. Eng. 2012, 47, 76–82. [Google Scholar] [CrossRef]
  59. Kyambadde, J.; Kansiime, F.; Gumaelius, L.; Dalhammar, G. A Comparative Study of Cyperus Papyrus and Miscanthidium Violaceum-Based Constructed Wetlands for Wastewater Treatment in a Tropical Climate. Water Res. 2004, 38, 475–485. [Google Scholar] [CrossRef]
  60. Konnerup, D.; Koottatep, T.; Brix, H. Treatment of Domestic Wastewater in Tropical, Subsurface Flow Constructed Wetlands Planted with Canna and Heliconia. Ecol. Eng. 2009, 35, 248–257. [Google Scholar] [CrossRef]
  61. Senzia, M.A.; Mashauri, D.A.; Mayo, A.W. Suitability of Constructed Wetlands and Waste Stabilisation Ponds in Wastewater Treatment: Nitrogen Transformation and Removal. Phys. Chem. Earth Parts A/B/C 2003, 28, 1117–1124. [Google Scholar] [CrossRef]
  62. Dias, S.; Mucha, A.P.; Duarte Crespo, R.; Rodrigues, P.; Almeida, C.M.R. Livestock Wastewater Treatment in Constructed Wetlands for Agriculture Reuse. Int. J. Environ. Res. Public Health 2020, 17, 8592. [Google Scholar] [CrossRef]
  63. Ranieri, E.; Gorgoglione, A.; Petrella, A.; Petruzzelli, V. Benzene Removal in Horizontal Subsurface Flow Constructed Wetlands Treatment. Int. J. Appl. Eng. Res. 2015, 10, 14603–14614. [Google Scholar]
  64. Meng, P.; Pei, H.; Hu, W.; Shao, Y.; Li, Z. How to Increase Microbial Degradation in Constructed Wetlands: Influencing Factors and Improvement Measures. Bioresour. Technol. 2014, 157, 316–326. [Google Scholar] [CrossRef]
  65. Park, J.-H.; Kim, S.-H.; Delaune, R.D.; Cho, J.-S.; Heo, J.-S.; Ok, Y.S.; Seo, D.-C. Enhancement of Nitrate Removal in Constructed Wetlands Utilizing a Combined Autotrophic and Heterotrophic Denitrification Technology for Treating Hydroponic Wastewater Containing High Nitrate and Low Organic Carbon Concentrations. Agric. Water Manag. 2015, 162, 1–14. [Google Scholar] [CrossRef]
  66. Kong, Z.; Wang, X.; Liu, Q.; Li, T.; Chen, X.; Chai, L.; Liu, D.; Shen, Q. Evolution of Various Fractions during the Windrow Composting of Chicken Manure with Rice Chaff. J. Environ. Manag. 2018, 207, 366–377. [Google Scholar] [CrossRef]
  67. Trang, N.T.D.; Konnerup, D.; Schierup, H.-H.; Chiem, N.H.; Tuan, L.A.; Brix, H. Kinetics of Pollutant Removal from Domestic Wastewater in a Tropical Horizontal Subsurface Flow Constructed Wetland System: Effects of Hydraulic Loading Rate. Ecol. Eng. 2010, 36, 527–535. [Google Scholar] [CrossRef]
  68. Hwang, J.H.; Oleszkiewicz, J.A. Effect of Cold-Temperature Shock on Nitrification. Water Environ. Res. 2007, 79, 964–968. [Google Scholar] [CrossRef] [PubMed]
  69. Tunçsiper, B. Nitrogen Removal in a Combined Vertical and Horizontal Subsurface-Flow Constructed Wetland System. Desalination 2009, 247, 466–475. [Google Scholar] [CrossRef]
  70. Stottmeister, U.; Wießner, A.; Kuschk, P.; Kappelmeyer, U.; Kästner, M.; Bederski, O.; Müller, R.A.; Moormann, H. Effects of Plants and Microorganisms in Constructed Wetlands for Wastewater Treatment. Biotechnol. Adv. 2003, 22, 93–117. [Google Scholar] [CrossRef]
  71. Kuschk, P.; Wießner, A.; Kappelmeyer, U.; Weißbrodt, E.; Kästner, M.; Stottmeister, U. Annual Cycle of Nitrogen Removal by a Pilot-Scale Subsurface Horizontal Flow in a Constructed Wetland under Moderate Climate. Water Res. 2003, 37, 4236–4242. [Google Scholar] [CrossRef]
  72. Baskar, G.; Deeptha, V.; Annadurai, R. Comparison of Treatment Performance Between Constructed Wetlands with Different Plants. Int. J. Res. Eng. Technol. 2014, 3, 210–214. [Google Scholar] [CrossRef]
  73. Hocaoglu, S.M.; Insel, G.; Cokgor, E.U.; Orhon, D. Effect of Low Dissolved Oxygen on Simultaneous Nitrification and Denitrification in a Membrane Bioreactor Treating Black Water. Bioresour. Technol. 2011, 102, 4333–4340. [Google Scholar] [CrossRef]
  74. Denisi, P.; Biondo, N.; Bombino, G.; Folino, A.; Zema, D.A.; Zimbone, S.M. A Combined System Using Lagoons and Constructed Wetlands for Swine Wastewater Treatment. Sustainability 2021, 13, 12390. [Google Scholar] [CrossRef]
  75. Borin, M.; Bonaiti, G.; Santamaria, G.; Giardini, L. A Constructed Surface Flow Wetland for Treating Agricultural Waste Waters. Water Sci. Technol. 2001, 44, 523–530. [Google Scholar] [CrossRef] [PubMed]
  76. Lopez, A.; Pollice, A.; Lonigro, A.; Masi, S.; Palese, A.M.; Cirelli, G.L.; Toscano, A.; Passino, R. Agricultural Wastewater Reuse in Southern Italy. Desalination 2006, 187, 323–334. [Google Scholar] [CrossRef]
  77. Mantovi, P.; Marmiroli, M.; Maestri, E.; Tagliavini, S.; Piccinini, S.; Marmiroli, N. Application of a Horizontal Subsurface Flow Constructed Wetland on Treatment of Dairy Parlor Wastewater. Bioresour. Technol. 2003, 88, 85–94. [Google Scholar] [CrossRef] [PubMed]
  78. Ferrario, C.; Peruzzi, C.; Cislaghi, A.; Polesello, S.; Valsecchi, S.; Lava, R.; Zanon, F.; Santovito, G.; Barausse, A.; Bonato, M. Assessment of Reed Grasses (Phragmites Australis) Performance in PFAS Removal from Water: A Phytoremediation Pilot Plant Study. Water 2022, 14, 946. [Google Scholar] [CrossRef]
  79. Masi, F.; Martinuzzi, N.; Bresciani, R.; Giovannelli, L.; Conte, G. Tolerance to Hydraulic and Organic Load Fluctuations in Constructed Wetlands. Water Sci. Technol. 2007, 56, 39–48. [Google Scholar] [CrossRef]
  80. Bianchi, E.; Coppi, A.; Nucci, S.; Antal, A.; Berardi, C.; Coppini, E.; Fibbi, D.; Del Bubba, M.; Gonnelli, C.; Colzi, I. Closing the Loop in a Constructed Wetland for the Improvement of Metal Removal: The Use of Phragmites Australis Biomass Harvested from the System as Biosorbent. Env. Sci Pollut Res 2021, 28, 11444–11453. [Google Scholar] [CrossRef]
  81. Toscano, A.; Marzo, A.; Milani, M.; Cirelli, G.L.; Barbagallo, S. Comparison of Removal Efficiencies in Mediterranean Pilot Constructed Wetlands Vegetated with Different Plant Species. Ecol. Eng. 2015, 75, 155–160. [Google Scholar] [CrossRef]
  82. Comino, E.; Riggio, V.A.; Rosso, M. Constructed Wetland Treatment of Agricultural Effluent from an Anaerobic Digester. Ecol. Eng. 2013, 54, 165–172. [Google Scholar] [CrossRef]
  83. Tuttolomondo, T.; Virga, G.; Licata, M.; Leto, C.; La Bella, S. Constructed Wetlands as Sustainable Technology for the Treatment and Reuse of the First-Flush Stormwater in Agriculture—A Case Study in Sicily (Italy). Water 2020, 12, 2542. [Google Scholar] [CrossRef]
  84. Russo, N.; Marzo, A.; Randazzo, C.; Caggia, C.; Toscano, A.; Cirelli, G.L. Constructed Wetlands Combined with Disinfection Systems for Removal of Urban Wastewater Contaminants. Sci. Total Environ. 2019, 656, 558–566. [Google Scholar] [CrossRef]
  85. Masi, F.; Rizzo, A.; Bresciani, R.; Conte, G. Constructed Wetlands for Combined Sewer Overflow Treatment: Ecosystem Services at Gorla Maggiore, Italy. Ecol. Eng. 2017, 98, 427–438. [Google Scholar] [CrossRef]
  86. Masi, F.; Martinuzzi, N. Constructed Wetlands for the Mediterranean Countries: Hybrid Systems for Water Reuse and Sustainable Sanitation. Desalination 2007, 215, 44–55. [Google Scholar] [CrossRef]
  87. Riggio, V.A.; Ruffino, B.; Campo, G.; Comino, E.; Comoglio, C.; Zanetti, M. Constructed Wetlands for the Reuse of Industrial Wastewater: A Case-Study. J. Clean. Prod. 2018, 171, 723–732. [Google Scholar] [CrossRef]
  88. Masi, F.; Rizzo, A.; Bresciani, R.; Basile, C. Dairy Wastewater Treatment by a Horizontal Subsurface Flow Constructed Wetland in Southern Italy. In Natural and Constructed Wetlands; Vymazal, J., Ed.; Springer International Publishing: Cham, Switzerland, 2016; pp. 131–139. ISBN 978-3-319-38926-4. [Google Scholar]
  89. Pucci, B.; Conte, G.; Martinuzzi, N.; Giovannelli, L.; Masi, F. Design and Performance of a Horizontal Flow Constructed Wetland for Treatment of Dairy and Agricultural Wastewater in the“Chianti” Countryside. In Proceedings of the IWA 7th International Conference on Wetland Systems for Water Pollution Control, Orlando, FL, USA, 11–16 November 2000; pp. 1433–1436. [Google Scholar]
  90. Coppini, E.; Palli, L.; Antal, A.; Del Bubba, M.; Miceli, E.; Fani, R.; Fibbi, D. Design and Start-up of a Constructed Wetland as Tertiary Treatment for Landfill Leachates. Water Sci. Technol. 2019, 79, 145–155. [Google Scholar] [CrossRef] [PubMed]
  91. Fibbi, D.; Doumett, S.; Lepri, L.; Checchini, L.; Gonnelli, C.; Coppini, E.; Del Bubba, M. Distribution and Mass Balance of Hexavalent and Trivalent Chromium in a Subsurface, Horizontal Flow (SF-h) Constructed Wetland Operating as Post-Treatment of Textile Wastewater for Water Reuse. J. Hazard. Mater. 2012, 199–200, 209–216. [Google Scholar] [CrossRef] [PubMed]
  92. Barbagallo, S.; Cirelli, G.L.; Marzo, A.; Milani, M.; Toscano, A. Effect of Different Plant Species in Pilot Constructed Wetlands for Wastewater Reuse in Agriculture. J Agric. Eng. 2013, 44, e160. [Google Scholar] [CrossRef]
  93. Leto, C.; Tuttolomondo, T.; La Bella, S.; Leone, R.; Licata, M. Effects of Plant Species in a Horizontal Subsurface Flow Constructed Wetland—Phytoremediation of Treated Urban Wastewater with Cyperus alternifolius L. and Typha latifolia L. in the West of Sicily (Italy). Ecol. Eng. 2013, 61, 282–291. [Google Scholar] [CrossRef]
  94. Aiello, R.; Bagarello, V.; Barbagallo, S.; Iovino, M.; Marzo, A.; Toscano, A. Evaluation of Clogging in Full-Scale Subsurface Flow Constructed Wetlands. Ecol. Eng. 2016, 95, 505–513. [Google Scholar] [CrossRef]
  95. Borin, M.; Tocchetto, D. Five Year Water and Nitrogen Balance for a Constructed Surface Flow Wetland Treating Agricultural Drainage Waters. Sci. Total Environ. 2007, 380, 38–47. [Google Scholar] [CrossRef]
  96. Rizzo, A.; Bresciani, R.; Martinuzzi, N.; Masi, F. French Reed Bed as a Solution to Minimize the Operational and Maintenance Costs of Wastewater Treatment from a Small Settlement: An Italian Example. Water 2018, 10, 156. [Google Scholar] [CrossRef]
  97. Dal Ferro, N.; De Mattia, C.; Gandini, M.A.; Maucieri, C.; Stevanato, P.; Squartini, A.; Borin, M. Green Walls to Treat Kitchen Greywater in Urban Areas: Performance from a Pilot-Scale Experiment. Sci. Total Environ. 2021, 757, 144189. [Google Scholar] [CrossRef] [PubMed]
  98. Comino, E.; Riggio, V.; Rosso, M. Grey Water Treated by an Hybrid Constructed Wetland Pilot Plant under Several Stress Conditions. Ecol. Eng. 2013, 53, 120–125. [Google Scholar] [CrossRef]
  99. Barbera, A.C.; Cirelli, G.L.; Cavallaro, V.; Di Silvestro, I.; Pacifici, P.; Castiglione, V.; Toscano, A.; Milani, M. Growth and Biomass Production of Different Plant Species in Two Different Constructed Wetland Systems in Sicily. Desalination 2009, 246, 129–136. [Google Scholar] [CrossRef]
  100. Leto, C.; Tuttolomondo, T.; Bella, S.L.; Leone, R.; Licata, M. Growth of Arundo donax L. and Cyperus alternifolius L. in a Horizontal Subsurface Flow Constructed Wetland Using Pre-Treated Urban Wastewater—A Case Study in Sicily (Italy). Desalination Water Treat. 2013, 51, 7447–7459. [Google Scholar] [CrossRef]
  101. Collivignarelli, M.C.; Carnevale Miino, M.; Gomez, F.H.; Torretta, V.; Rada, E.C.; Sorlini, S. Horizontal Flow Constructed Wetland for Greywater Treatment and Reuse: An Experimental Case. Int. J. Environ. Res. Public Health 2020, 17, 2317. [Google Scholar] [CrossRef]
  102. Barbagallo, S.; Cirelli, G.L.; Marzo, A.; Milani, M.; Toscano, A. Hydraulic Behaviour and Removal Efficiencies of Two H-SSF Constructed Wetlands for Wastewater Reuse with Different Operational Life. Water Sci. Technol. 2011, 64, 1032–1039. [Google Scholar] [CrossRef]
  103. Marzo, A.; Ventura, D.; Cirelli, G.L.; Aiello, R.; Vanella, D.; Rapisarda, R.; Barbagallo, S.; Consoli, S. Hydraulic Reliability of a Horizontal Wetland for Wastewater Treatment in Sicily. Sci. Total Environ. 2018, 636, 94–106. [Google Scholar] [CrossRef]
  104. Chiavola, A.; Bagolan, C.; Moroni, M.; Bongirolami, S. Hyperspectral Monitoring of a Constructed Wetland as a Tertiary Treatment in a Wastewater Treatment Plant. Int. J. Environ. Sci. Technol. 2020, 17, 3751–3760. [Google Scholar] [CrossRef]
  105. Spiniello, I.; De Carluccio, M.; Castiglione, S.; Amineva, E.; Kostryukova, N.; Cicatelli, A.; Rizzo, L.; Guarino, F. Landfill Leachate Treatment by a Combination of a Multiple Plant Hybrid Constructed Wetland System with a Solar PhotoFenton Process in a Raceway Pond Reactor. J. Environ. Manag. 2023, 331, 117211. [Google Scholar] [CrossRef]
  106. Lavrnić, S.; Braschi, I.; Anconelli, S.; Blasioli, S.; Solimando, D.; Mannini, P.; Toscano, A. Long-Term Monitoring of a Surface Flow Constructed Wetland Treating Agricultural Drainage Water in Northern Italy. Water 2018, 10, 644. [Google Scholar] [CrossRef]
  107. Ventura, D.; Ferrante, M.; Copat, C.; Grasso, A.; Milani, M.; Sacco, A.; Licciardello, F.; Cirelli, G.L. Metal Removal Processes in a Pilot Hybrid Constructed Wetland for the Treatment of Semi Synthetic Stormwater. Sci. Total Environ. 2021, 754, 142221. [Google Scholar] [CrossRef] [PubMed]
  108. Pappalardo, S.E.; Otto, S.; Gasparini, V.; Zanin, G.; Borin, M. Mitigation of Herbicide Runoff as an Ecosystem Service from a Constructed Surface Flow Wetland. Hydrobiologia 2016, 774, 193–202. [Google Scholar] [CrossRef]
  109. Comino, E.; Riggio, V.; Rosso, M. Mountain Cheese Factory Wastewater Treatment with the Use of a Hybrid Constructed Wetland. Ecol. Eng. 2011, 37, 1673–1680. [Google Scholar] [CrossRef]
  110. Gorra, R.; Freppaz, M.; Zanini, E.; Scalenghe, R. Mountain Dairy Wastewater Treatment with the Use of a ‘Irregularly Shaped’ Constructed Wetland (Aosta Valley, Italy). Ecol. Eng. 2014, 73, 176–183. [Google Scholar] [CrossRef]
  111. Masi, F.; Caffaz, S.; Ghrabi, A. Multi-Stage Constructed Wetland Systems for Municipal Wastewater Treatment. Water Sci. Technol. 2013, 67, 1590–1598. [Google Scholar] [CrossRef]
  112. Tolomio, M.; Dal Ferro, N.; Borin, M. Multi-Year N and P Removal of a 10-Year-Old Surface Flow Constructed Wetland Treating Agricultural Drainage Waters. Agronomy 2019, 9, 170. [Google Scholar] [CrossRef]
  113. Dal Ferro, N.; Ibrahim, H.M.S.; Borin, M. Newly-Established Free Water-Surface Constructed Wetland to Treat Agricultural Waters in the Low-Lying Venetian Plain: Performance on Nitrogen and Phosphorus Removal. Sci. Total Environ. 2018, 639, 852–859. [Google Scholar] [CrossRef]
  114. Del Bubba, M.; Checchini, L.; Pifferi, C.; Zanieri, L.; Lepri, L. Olive Mill Wastewater Treatment by a Pilot-Scale Subsurface Horizontal Flow (SSF-h) Constructed Wetland. Ann. Di Chim. 2004, 94, 875–887. [Google Scholar] [CrossRef]
  115. Rizzo, A.; Bresciani, R.; Martinuzzi, N.; Masi, F. Online Monitoring of a Long-Term Full-Scale Constructed Wetland for the Treatment of Winery Wastewater in Italy. Appl. Sci. 2020, 10, 555. [Google Scholar] [CrossRef]
  116. Macci, C.; Peruzzi, E.; Doni, S.; Iannelli, R.; Masciandaro, G. Ornamental Plants for Micropollutant Removal in Wetland Systems. Environ. Sci. Pollut. Res. 2015, 22, 2406–2415. [Google Scholar] [CrossRef] [PubMed]
  117. Ranieri, E.; Verlicchi, P.; Young, T.M. Paracetamol Removal in Subsurface Flow Constructed Wetlands. J. Hydrol. 2011, 404, 130–135. [Google Scholar] [CrossRef]
  118. Lavrnić, S.; Nan, X.; Blasioli, S.; Braschi, I.; Anconelli, S.; Toscano, A. Performance of a Full Scale Constructed Wetland as Ecological Practice for Agricultural Drainage Water Treatment in Northern Italy. Ecol. Eng. 2020, 154, 105927. [Google Scholar] [CrossRef]
  119. Borin, M.; Politeo, M.; De Stefani, G. Performance of a Hybrid Constructed Wetland Treating Piggery Wastewater. Ecol. Eng. 2013, 51, 229–236. [Google Scholar] [CrossRef]
  120. Licata, M.; Rossini, F.; Virga, G.; Ruggeri, R.; Farruggia, D.; Iacuzzi, N. Performance of a PilotScale Constructed Wetland and Medium-Term Effects of Treated Wastewater Irrigation of Arundo donax L. on Soil and Plant Parameters. Water 2021, 13, 1994. [Google Scholar] [CrossRef]
  121. Mietto, A.; Borin, M. Performance of Two Small Subsurface Flow Constructed Wetlands Treating Domestic Wastewaters in Italy. Environ. Technol. 2013, 34, 1085–1095. [Google Scholar] [CrossRef] [PubMed]
  122. Ceschin, S.; Sgambato, V.; Ellwood, N.T.W.; Zuccarello, V. Phytoremediation Performance of Lemna Communities in a Constructed Wetland System for Wastewater Treatment. Environ. Exp. Bot. 2019, 162, 67–71. [Google Scholar] [CrossRef]
  123. La Bella, S.; Tuttolomondo, T.; Leto, C.; Bonsangue, G.; Leone, R.; Virga, G.; Licata, M. Pollutant Removal Efficiency of a Pilot-Scale Horizontal Subsurface Flow in Sicily (Italy) Planted with Cyperus alternifolius L. and Typha latifolia L. and Reuse of Treated Wastewater for Irrigation of Arundo donax L. for Pellet Production—Results of Two-Year Tests under Mediterranean Climatic Conditions. Desalination Water Treat. 2016, 57, 22743–22763. [Google Scholar] [CrossRef]
  124. Politeo, M.; Morin, M.; Milani, M.; Toscano, A.; Molari, G. Production and Energy Value of Phragmites australis Obtained from Two Constructed Wetlands. In Proceedings of the 19th European Bio-mass Conference and Exhibition, Berlin, Germany, 6–10 June 2011. [Google Scholar]
  125. Galletti, A.; Verlicchi, P.; Ranieri, E. Removal and Accumulation of Cu, Ni and Zn in Horizontal Subsurface Flow Constructed Wetlands: Contribution of Vegetation and Filling Medium. Sci. Total Environ. 2010, 408, 5097–5105. [Google Scholar] [CrossRef]
  126. Ranieri, E.; Gorgoglione, A.; Montanaro, C.; Iacovelli, A.; Gikas, P. Removal Capacity of BTEX and Metals of Constructed Wetlands under the Influence of Hydraulic Conductivity. Desalination Water Treat. 2015, 56, 1256–1263. [Google Scholar] [CrossRef]
  127. Toscano, A.; Hellio, C.; Marzo, A.; Milani, M.; Lebret, K.; Cirelli, G.L.; Langergraber, G. Removal Efficiency of a Constructed Wetland Combined with Ultrasound and UV Devices for Wastewater Reuse in Agriculture. Environ. Technol. 2013, 34, 2327–2336. [Google Scholar] [CrossRef] [PubMed]
  128. Gikas, P.; Ranieri, E.; Tchobanoglous, G. Removal of Iron, Chromium and Lead from Waste Water by Horizontal Subsurface Flow Constructed Wetlands: Removal of Heavy Metals from Waste Water by Horizontal Subsurface Flow Constructed Wetlands. J. Chem. Technol. Biotechnol. 2013, 88, 1906–1912. [Google Scholar] [CrossRef]
  129. Francini, A.; Mariotti, L.; Di Gregorio, S.; Sebastiani, L.; Andreucci, A. Removal of Micro-Pollutants from Urban Wastewater by Constructed Wetlands with Phragmites Australis and Salix Matsudana. Environ. Sci. Pollut. Res. 2018, 25, 36474–36484. [Google Scholar] [CrossRef]
  130. Verlicchi, P.; Galletti, A.; Petrovic, M.; Barceló, D.; Al Aukidy, M.; Zambello, E. Removal of Selected Pharmaceuticals from Domestic Wastewater in an Activated Sludge System Followed by a Horizontal Subsurface Flow Bed—Analysis of Their Respective Contributions. Sci. Total Environ. 2013, 454–455, 411–425. [Google Scholar] [CrossRef] [PubMed]
  131. Licata, M.; Gennaro, M.C.; Tuttolomondo, T.; Leto, C.; La Bella, S. Research Focusing on Plant Performance in Constructed Wetlands and Agronomic Application of Treated Wastewater—A Set of Experimental Studies in Sicily (Italy). PLoS ONE 2019, 14, e0219445. [Google Scholar] [CrossRef]
  132. Licata, M.; La Bella, S.; Leto, C.; Virga, G.; Leone, R.; Bonsangue, G.; Tuttolomondo, T. Reuse of Urban-Treated Wastewater from a Pilot-Scale Horizontal Subsurface Flow System in Sicily (Italy) for Irrigation of Bermudagrass (Cynodon dactylon (L.) Pers.) Turf under Mediterranean Climatic Conditions. Desalination Water Treat. 2016, 57, 23343–23364. [Google Scholar] [CrossRef]
  133. Licata, M.; Farruggia, D.; Tuttolomondo, T.; Iacuzzi, N.; Leto, C.; Di Miceli, G. Seasonal Response of Vegetation on Pollutants Removal in Constructed Wetland System Treating Dairy Wastewater. Ecol. Eng. 2022, 182, 106727. [Google Scholar] [CrossRef]
  134. Bragato, C.; Schiavon, M.; Polese, R.; Ertani, A.; Pittarello, M.; Malagoli, M. Seasonal Variations of Cu, Zn, Ni and Cr Concentration in Phragmites Australis (Cav.) Trin Ex Steudel in a Constructed Wetland of North Italy. Desalination 2009, 246, 35–44. [Google Scholar] [CrossRef]
  135. Cirelli, G.L.; Consoli, S.; Di Grande, V.; Milani, M.; Toscano, A. Subsurface Constructed Wetlands for Wastewater Treatment and Reuse in Agriculture: Five Years of Experiences in Sicily, Italy. Water Sci. Technol. 2007, 56, 183–191. [Google Scholar] [CrossRef]
  136. Mietto, A.; Politeo, M.; Breschigliaro, S.; Borin, M. Temperature Influence on Nitrogen Removal in a Hybrid Constructed Wetland System in Northern Italy. Ecol. Eng. 2015, 75, 291–302. [Google Scholar] [CrossRef]
  137. Lavrnić, S.; Pereyra, M.Z.; Cristino, S.; Cupido, D.; Lucchese, G.; Pascale, M.R.; Toscano, A.; Mancini, M. The Potential Role of Hybrid Constructed Wetlands Treating University Wastewater—Experience from Northern Italy. Sustainability 2020, 12, 10604. [Google Scholar] [CrossRef]
  138. Licata, M.; Tuttolomondo, T.; Leto, C.; La Bella, S.; Virga, G. The Use of Constructed Wetlands for the Treatment and Reuse of Urban Wastewater for the Irrigation of Two Warm-Season Turfgrass Species under Mediterranean Climatic Conditions. Water Sci. Technol. 2017, 76, 459–470. [Google Scholar] [CrossRef] [PubMed]
  139. Fibbi, D.; Doumett, S.; Colzi, I.; Coppini, E.; Pucci, S.; Gonnelli, C.; Lepri, L.; Del Bubba, M. Total and Hexavalent Chromium Removal in a Subsurface Horizontal Flow (h-SSF) Constructed Wetland Operating as Post-Treatment of Textile Wastewater for Water Reuse. Water Sci. Technol. 2011, 64, 826–831. [Google Scholar] [CrossRef]
  140. Licata, M.; Ruggeri, R.; Iacuzzi, N.; Virga, G.; Farruggia, D.; Rossini, F.; Tuttolomondo, T. Treatment of Combined Dairy and Domestic Wastewater with Constructed Wetland System in Sicily (Italy). Pollut. Remov. Effic. Eff. Vegetation. Water 2021, 13, 1086. [Google Scholar] [CrossRef]
  141. De Feo, G.; Lofrano, G.; Belgiorno, V. Treatment of High Strength Wastewater with Vertical Flow Constructed Wetland Filters. Water Sci. Technol. 2005, 51, 139–146. [Google Scholar] [CrossRef] [PubMed]
  142. Milani, M.; Consoli, S.; Marzo, A.; Pino, A.; Randazzo, C.; Barbagallo, S.; Cirelli, G.L. Treatment of Winery Wastewater with a Multistage Constructed Wetland System for Irrigation Reuse. Water 2020, 12, 1260. [Google Scholar] [CrossRef]
  143. Maucieri, C.; Mietto, A.; Barbera, A.C.; Borin, M. Treatment Performance and Greenhouse Gas Emission of a Pilot Hybrid Constructed Wetland System Treating Digestate Liquid Fraction. Ecol. Eng. 2016, 94, 406–417. [Google Scholar] [CrossRef]
  144. Barco, A.; Borin, M. Treatment Performance and Macrophytes Growth in a Restored Hybrid Constructed Wetland for Municipal Wastewater Treatment. Ecol. Eng. 2017, 107, 160–171. [Google Scholar] [CrossRef]
  145. Cocozza, C.; Di Iaconi, C.; Murgolo, S.; Traversa, A.; De Mastro, F.; De Sanctis, M.; Altieri, V.G.; Cacace, C.; Brunetti, G.; Mascolo, G. Use of Constructed Wetlands to Prevent Overloading of Wastewater Treatment Plants. Chemosphere 2023, 311, 137126. [Google Scholar] [CrossRef]
  146. Maucieri, C.; Salvato, M.; Borin, M. Vegetation Contribution on Phosphorus Removal in Constructed Wetlands. Ecol. Eng. 2020, 152, 105853. [Google Scholar] [CrossRef]
  147. Albuzio, A.; Lubian, C.; Parolin, R.; Balsamo, R.; Camerin, I.; Valerio, P. Wastewater from a Mountain Village Treated with a Constructed Wetland. Desalination Water Treat. 2009, 1, 232–236. [Google Scholar] [CrossRef]
  148. Tuttolomondo, T.; Leto, C.; La Bella, S.; Leone, R.; Virga, G.; Licata, M. Water Balance and Pollutant Removal Efficiency When Considering Evapotranspiration in a Pilot-Scale Horizontal Subsurface Flow Constructed Wetland in Western Sicily (Italy). Ecol. Eng. 2016, 87, 295–304. [Google Scholar] [CrossRef]
  149. Kiran Kumar, V.; Man mohan, K.; Manangath, S.P.; Gajalakshmi, S. Innovative Pilot-Scale Constructed Wetland-Microbial Fuel Cell System for Enhanced Wastewater Treatment and Bioelectricity Production. Chem. Eng. J. 2023, 460, 141686. [Google Scholar] [CrossRef]
  150. Wang, S.; Gong, Z.; Wang, Y.; Cheng, F.; Lu, X. An Anoxic-Aerobic System Combined with Integrated Vertical-Flow Constructed Wetland to Highly Enhance Simultaneous Organics and Nutrients Removal in Rural China. J. Environ. Manag. 2023, 332, 117349. [Google Scholar] [CrossRef] [PubMed]
  151. Alayu, E.; Leta, S.; Alemu, T.; Mekonnen, A. Combined Effect of Macrophytes for Enhanced Pollutant Removals from Anaerobic Reactor Brewery Effluent. Wetlands 2023, 43, 13. [Google Scholar] [CrossRef]
  152. Saeed, T.; Yadav, A.K.; Miah, M.J. Treatment Performance of Stone Dust Packed Tidal Flow Electroactive and Normal Constructed Wetlands: Influence of Contact Time, Plants, and Electrodes. J. Water Process Eng. 2022, 50, 103257. [Google Scholar] [CrossRef]
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MDPI and ACS Style

Retta, B.; Coppola, E.; Ciniglia, C.; Grilli, E. Constructed Wetlands for the Wastewater Treatment: A Review of Italian Case Studies. Appl. Sci. 2023, 13, 6211. https://doi.org/10.3390/app13106211

AMA Style

Retta B, Coppola E, Ciniglia C, Grilli E. Constructed Wetlands for the Wastewater Treatment: A Review of Italian Case Studies. Applied Sciences. 2023; 13(10):6211. https://doi.org/10.3390/app13106211

Chicago/Turabian Style

Retta, Berhan, Elio Coppola, Claudia Ciniglia, and Eleonora Grilli. 2023. "Constructed Wetlands for the Wastewater Treatment: A Review of Italian Case Studies" Applied Sciences 13, no. 10: 6211. https://doi.org/10.3390/app13106211

APA Style

Retta, B., Coppola, E., Ciniglia, C., & Grilli, E. (2023). Constructed Wetlands for the Wastewater Treatment: A Review of Italian Case Studies. Applied Sciences, 13(10), 6211. https://doi.org/10.3390/app13106211

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