Water

Research

1880 KiB

Open AccessArticle

Spatio-Temporal Impacts of Biofuel Production and Climate Variability on Water Quantity and Quality in Upper Mississippi River Basin

by Debjani Deb, Pushpa Tuppad, Prasad Daggupati, Raghavan Srinivasan and Deepa Varma

Water 2015, 7(7), 3283-3305; https://doi.org/10.3390/w7073283 - 26 Jun 2015

Cited by 21 | Viewed by 7226

Abstract

Impact of climate change on the water resources of the United States exposes the vulnerability of feedstock-specific mandated fuel targets to extreme weather conditions that could become more frequent and intensify in the future. Consequently, a sustainable biofuel policy should consider: (a) how [...] Read more.

Impact of climate change on the water resources of the United States exposes the vulnerability of feedstock-specific mandated fuel targets to extreme weather conditions that could become more frequent and intensify in the future. Consequently, a sustainable biofuel policy should consider: (a) how climate change would alter both water supply and demand; and (b) in turn, how related changes in water availability will impact the production of biofuel crops; and (c) the environmental implications of large scale biofuel productions. Understanding the role of biofuels in the water cycle is the key to understanding many of the environmental impacts of biofuels. Therefore, the focus of this study is to model the rarely explored interactions between land use, climate change, water resources and the environment in future biofuel production systems. Results from this study will help explore the impacts of the US biofuel policy and climate change on water and agricultural resources. We used the Soil and Water Assessment Tool (SWAT) to analyze the water quantity and quality consequences of land use and land management related changes in cropping conditions (e.g., more use of marginal lands, greater residue harvest, increased yields), plus management practices due to biofuel crops to meet the Renewable Fuel Standard target on water quality and quantity. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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3432 KiB

Open AccessArticle

Initial Characterization and Water Quality Assessment of Stream Landscapes in Northern Mongolia

by Jürgen Hofmann, Daniel Karthe, Ralf Ibisch, Michael Schäffer, Saulyegul Avlyush, Sonja Heldt and Andrew Kaus

Water 2015, 7(7), 3166-3205; https://doi.org/10.3390/w7073166 - 25 Jun 2015

Cited by 29 | Viewed by 9918

Abstract

A comprehensive monitoring project (2006–2013) provided data on hydrology, hydromorphology, climatology, water physico-chemistry, sedimentology, macroinvertebrate community and fish diversity in the Kharaa River basin in northern Mongolia, thus enabling, for the first time, a detailed characterization of the stream landscapes. Surface waters were [...] Read more.

A comprehensive monitoring project (2006–2013) provided data on hydrology, hydromorphology, climatology, water physico-chemistry, sedimentology, macroinvertebrate community and fish diversity in the Kharaa River basin in northern Mongolia, thus enabling, for the first time, a detailed characterization of the stream landscapes. Surface waters were categorized into separate “water bodies” according to their identifiable abiotic and biocoenotic features, subsequently creating the smallest management sub-units within the river basin. Following the approach of the European Water Framework Directive (EC-WFD), in order to obtain a good ecological status (GES), four clearly identifiable water bodies in the Kharaa River main channel and seven water bodies consisting of the basin’s tributaries were delineated. The type-specific undisturbed reference state of various aquatic ecosystems was identified in the assessment and used to set standards for restoration goals. With regards to water quality and quantity, the upper reaches of the Kharaa River basin in the Khentii Mountains were classified as having a “good” ecological and chemical status. Compared with these natural reference conditions in the upper reaches, the initial risk assessment identified several “hot spot” regions with impacted water bodies in the middle and lower basin. Subsequently, the affected water bodies are at risk of not obtaining a level of good ecological and/or chemical status for surface waters. Finally, a matrix of cause-response relationships and stressor complexes has been developed and is presented here. The applicability of management approaches is discussed to better foster the development of a sustainable river basin management plan. The application of natural references states offers a sound scientific base to assess the impact of anthropogenic activities across the Kharaa River basin. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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858 KiB

Open AccessArticle

Removal of Metaldehyde from Water Using a Novel Coupled Adsorption and Electrochemical Destruction Technique

by Mohammed A. Nabeerasool, Andrew K. Campen, David A. Polya, Nigel W. Brown and Bart E. Van Dongen

Water 2015, 7(6), 3057-3071; https://doi.org/10.3390/w7063057 - 19 Jun 2015

Cited by 13 | Viewed by 8689

Abstract

Metaldehyde is a selective pesticide applied to control snails and slugs and which, particularly when application rates are high and during periods of high rainfall, may find its way into water courses, some of which may be used as drinking water supplies. Existing [...] Read more.

Metaldehyde is a selective pesticide applied to control snails and slugs and which, particularly when application rates are high and during periods of high rainfall, may find its way into water courses, some of which may be used as drinking water supplies. Existing water treatment processes have been inadequate for reducing metaldehyde residual levels (up to 8 µg/L) found in some waters to below the EU/UK statutory limit of 0.1 µg/L. Here a novel coupled adsorption and electrochemical regeneration technology is tested to determine if it is capable of effectively removing metaldehyde. We demonstrate that metaldehyde is not only adsorbed on the adsorbent used but is also destroyed during the regeneration stage, resulting in residual metaldehyde concentrations below the EU/UK regulatory limit for drinking water. No known harmful breakdown by-products were observed to be generated by the process. The effectiveness of the process seems unaffected by organic-rich peat water, indicating the potential for the treatment of drinking water much of which in the UK is derived from upland peaty catchments. Furthermore, successive spiking experiments showed that this technology has the potential to be applied as a continuous process without the generation of substantial waste products. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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448 KiB

Open AccessArticle

Effects of Misgurnus anguillicaudatus and Cipangopaludina cathayensis on Pollutant Removal and Microbial Community in Constructed Wetlands

by Pengfei Li, Jian Zhang, Huijun Xie, Zhen Hu, Haiyan He and Wenxing Wang

Water 2015, 7(5), 2422-2434; https://doi.org/10.3390/w7052422 - 21 May 2015

Cited by 9 | Viewed by 6375

Abstract

Aquatic animals play an important role in the energy flow and matter cycling in the wetland ecosystem. However, little is known about their effects on pollutant removal performance and microbial community in constructed wetlands. This work presents an initial attempt to investigate the [...] Read more.

Aquatic animals play an important role in the energy flow and matter cycling in the wetland ecosystem. However, little is known about their effects on pollutant removal performance and microbial community in constructed wetlands. This work presents an initial attempt to investigate the effects of Misgurnus anguillicaudatus (loach) and Cipangopaludina cathayensis (snail) on nutrient removal performance and microbial community of constructed wetlands (CWs). Compared with a control group, CW microcosms with aquatic animals exhibited better pollutant removal performance. The removal efficiencies of total phosphorus (TP) in the loach group were 13.1% higher than in the control group, and snails increased the ammonium removal most effectively. Moreover, the concentration of total organic carbon (TOC) and TP in sediment significantly reduced with the addition of loaches and snails (p < 0.05), whereas the concentration of total nitrogen (TN) showed an obvious increase with the addition of loaches. High-throughput sequencing showed a microbial community structure change. Loaches and snails in wetlands changed the microbial diversity, especially in the Proteobacteria and denitrifying community. Results suggested that benthic aquatic animals might play an important role in CW ecosystems. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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1227 KiB

Open AccessArticle

Effect of COD:SO₄ ²⁻ Ratio, HRT and Linoleic Acid Concentration on Mesophilic Sulfate Reduction: Reactor Performance and Microbial Population Dynamics

by Chungman Moon, Rajesh Singh, Sathyanarayan S. Veeravalli, Saravanan R. Shanmugam, Subba Rao Chaganti, Jerald A. Lalman and Daniel D. Heath

Water 2015, 7(5), 2275-2292; https://doi.org/10.3390/w7052275 - 18 May 2015

Cited by 24 | Viewed by 8189

Abstract

Biological sulfate (SO₄²⁻) reduction was examined in anaerobic sequential batch reactors (ASBRs) operated under different hydraulic retention times (HRTs) ranging from 12 to 36 h and COD (Chemical Oxygen Demand)/SO₄²⁻) ratios of 2.4, 1.6 and 0.8. Competition [...] Read more.

Biological sulfate (SO₄²⁻) reduction was examined in anaerobic sequential batch reactors (ASBRs) operated under different hydraulic retention times (HRTs) ranging from 12 to 36 h and COD (Chemical Oxygen Demand)/SO₄²⁻) ratios of 2.4, 1.6 and 0.8. Competition between SO₄²⁻ reducing bacteria (SRBs), methane producing archaea (MPAs) and homoacetogens (HACs) was examined in controls and cultures treated with linoleic acid (LA). The ASBR performance was influenced by the COD/SO₄²⁻ ratio in control cultures with a SO₄²⁻ reduction of 87% at a COD/SO₄²⁻ ratio of 0.8. At a 12 h HRT, in both control and LA treated cultures, greater than 75% SO₄²⁻ removal was observed under all the conditions examined. In control reactors operating at a 36 h HRT, high levels of MPAs belonging to Methanobacteriales and Methanosarcinales were detected; however, in comparison, under low COD/SO₄²⁻ ratio and with decreasing HRT conditions, a relative increase in SRBs belonging to Desulfovibrio and Desulfatibacillum was observed. Adding 0.5 g·L⁻¹ LA suppressed Methanobacteriales, while increasing the LA concentration to 1 g·L⁻¹ completely suppressed MPAs with a relative increase in SRBs. HACs belonging to Bacteroidetes were observed in the control and in cultures operated at 12 h HRT with a COD/SO₄²⁻ ratio of 1.6 and fed 0.5 g·L⁻¹ LA; however, with all other LA levels (0.5 and 1.0 g·L⁻¹) and HRTs (12, 24 and 36 h), HACs were not detected. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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2490 KiB

Open AccessArticle

Assessing Potential Algal Blooms in a Shallow Fluvial Lake by Combining Hydrodynamic Modelling and Remote-Sensed Images

by Monica Pinardi, Andrea Fenocchi, Claudia Giardino, Stefano Sibilla, Marco Bartoli and Mariano Bresciani

Water 2015, 7(5), 1921-1942; https://doi.org/10.3390/w7051921 - 28 Apr 2015

Cited by 33 | Viewed by 7396

Abstract

Shallow fluvial lakes are dynamic ecosystems shaped by physical and biological factors and characterized by the coexistence of phytoplankton and macrophytes. Due to multiple interplaying factors, understanding the distribution of phytoplankton in fluvial lakes is a complex but fundamental issue, in the context [...] Read more.

Shallow fluvial lakes are dynamic ecosystems shaped by physical and biological factors and characterized by the coexistence of phytoplankton and macrophytes. Due to multiple interplaying factors, understanding the distribution of phytoplankton in fluvial lakes is a complex but fundamental issue, in the context of increasing eutrophication, climate change, and multiple water uses. We analyze the distribution of phytoplankton by combining remotely sensed maps of chlorophyll-a with a hydrodynamic model in a dammed fluvial lake (Mantua Superior Lake, Northern Italy). The numerical simulation of different conditions shows that the main hydrodynamic effects which influence algal distribution are related to the combined effect of advection due to wind forces and local currents, as well as to the presence of large gyres which induce recirculation and stagnation regions, favoring phytoplankton accumulation. Therefore, the general characters of the phytoplankton horizontal patchiness can be inferred from the results of the hydrodynamic model. Conversely, hyperspectral remote-sensing products can be used to validate this model, as they provide chlorophyll-a distribution maps. The integration of ecological, hydraulic, and remote-sensing techniques may therefore help the monitoring and protection of inland water quality, with important improvements in management actions by policy makers. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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2612 KiB

Open AccessArticle

Quantification of Water and Salt Exchanges in a Tidal Estuary

by Janesh Devkota and Xing Fang

Water 2015, 7(5), 1769-1791; https://doi.org/10.3390/w7051769 - 24 Apr 2015

Cited by 5 | Viewed by 7200

Abstract

A calibrated three-dimensional hydrodynamic model was applied to study subtidal water and salt exchanges at various cross sections of the Perdido Bay and Wolf Bay system using the Eulerian decomposition method from 6 September 2008 to 13 July 2009. Salinity, velocity, and water [...] Read more.

A calibrated three-dimensional hydrodynamic model was applied to study subtidal water and salt exchanges at various cross sections of the Perdido Bay and Wolf Bay system using the Eulerian decomposition method from 6 September 2008 to 13 July 2009. Salinity, velocity, and water levels at each cross section were extracted from the model output to compute flow rates and salt fluxes. Eulerian analysis concluded that salt fluxes (exchanges) at the Perdido Pass and Dolphin Pass cross sections were dominated by tidal oscillatory transport F_T_, whereas shear dispersive transport F_E (shear dispersion due to vertical and lateral shear transport) was dominant at the Perdido Pass complex, the Wolf-Perdido canal, and the lower Perdido Bay cross sections. The flow rate Q_F and total salt transport rate F_S showed distinct variation in response to complex interactions between discharges from upstream rivers and tidal boundaries. Q_F and F_S ranged from −619 m³·s⁻¹ (seaward) to 179 m³·s⁻¹ (landward) and −13,480–6289 kg·s⁻¹ at Perdido Pass when river discharges ranged 11.0–762.5 m³·s⁻¹ in the 2008–2009 simulation period. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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6627 KiB

Open AccessArticle

Estimating the Impact of Inflow on the Chemistry of Two Different Caldera Type Lakes Located on the Bali Island (Indonesia)

by Żaneta Polkowska, Lidia Wolska, Leszek Łęczyński, Marek Ruman, Sara Lehmann, Katarzyna Kozak, Magdalena Matysik and Damian Absalon

Water 2015, 7(4), 1712-1730; https://doi.org/10.3390/w7041712 - 21 Apr 2015

Cited by 4 | Viewed by 6623

Abstract

This paper is a preliminary attempt to assess the composition of pollutants in two different caldera lakes situated in the Indonesian Archipelago: Batur and Bratan. Both lakes are characterized by largely different physico-chemical regimes; Batur Lake is located in an area that is [...] Read more.

This paper is a preliminary attempt to assess the composition of pollutants in two different caldera lakes situated in the Indonesian Archipelago: Batur and Bratan. Both lakes are characterized by largely different physico-chemical regimes; Batur Lake is located in an area that is currently volcanically active, unlike Bratan Lake. The latter is much smaller and shallower than Batur Lake. The concentration of pollutants in the Indonesian equatorial lakes is largely unknown, and the impact of both biological and geothermal processes on their distribution requires attention. This study shows that the concentrations of cations (Na⁺, K⁺, Mg²⁺, Ca²⁺), anions (SO₄²⁻, F⁻, Cl⁻, Br⁻) and trace elements (Li, B, Al, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Cd, Sn, Cs, Ba, Pb, U, Be, Ag, Sb, Tl, Bi) differ greatly between both lakes. Most chemical parameters determined in volcanically influenced Batur Lake were tens to hundreds times higher than in Bratan Lake, and in the case of trace metals, the ratios of the two lakes’ concentrations reached several hundreds. This study also compared the composition and concentration levels of organic compounds in both lakes, such as fatty acids, halocarbons and esters. On the other hand, the content of organic chemicals in the lakes also results from biological activity by phytoplankton, zooplankton and bacteria. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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1091 KiB

Open AccessArticle

Laboratory Studies on Granular Filters and Their Relationship to Geotextiles for Stormwater Pollutant Reduction

by Parneet Paul and Kiran Tota-Maharaj

Water 2015, 7(4), 1595-1609; https://doi.org/10.3390/w7041595 - 15 Apr 2015

Cited by 15 | Viewed by 9516

Abstract

Applications of geotextiles within tertiary stormwater treatment systems and for stormwater infiltration can provide a substrate for biofilm formation, enabling biological treatment of contaminants. Geotextiles can serve as an efficient part of stormwater filtration within the urban water environment. The project assessed the [...] Read more.

Applications of geotextiles within tertiary stormwater treatment systems and for stormwater infiltration can provide a substrate for biofilm formation, enabling biological treatment of contaminants. Geotextiles can serve as an efficient part of stormwater filtration within the urban water environment. The project assessed the applications of three experimental granular filters as a sustainable urban drainage system (SUDS) for the decomposition of organic pollutant loading present in stormwater. The three filter rigs were packed with alternating layers of filter media consisting of gravel, pea gravel, sand and either a single, double or no layer of geotextile membrane. A nonwoven geotextile was layered within the filter media. The hydraulic loading capacity for the three filters matched that commonly used with conventional sand filters systems. Water quality parameters were quantified by measuring suspended solids, chemical oxygen demand, dissolved oxygen, pH, nitrate-nitrogen, and phosphate concentrations. It was found that Filter Rig No. 3 (upper and lower geotextile membrane) and Filter Rig No. 2 (single geotextile membrane) had a significant statistical difference in treatment performance from Filter Rig No. 1 (no geotextile membrane). Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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367 KiB

Open AccessArticle

Chemical Analysis of Wastewater from Unconventional Drilling Operations

by Jonathan B. Thacker, Doug D. Carlton, Jr., Zacariah L. Hildenbrand, Akinde F. Kadjo and Kevin A. Schug

Water 2015, 7(4), 1568-1579; https://doi.org/10.3390/w7041568 - 15 Apr 2015

Cited by 78 | Viewed by 11906

Abstract

Trillions of liters of wastewater from oil and gas extraction are generated annually in the US. The contribution from unconventional drilling operations (UDO), such as hydraulic fracturing, to this volume will likely continue to increase in the foreseeable future. The chemical content of [...] Read more.

Trillions of liters of wastewater from oil and gas extraction are generated annually in the US. The contribution from unconventional drilling operations (UDO), such as hydraulic fracturing, to this volume will likely continue to increase in the foreseeable future. The chemical content of wastewater from UDO varies with region, operator, and elapsed time after production begins. Detailed chemical analyses may be used to determine its content, select appropriate treatment options, and identify its source in cases of environmental contamination. In this study, one wastewater sample each from direct effluent, a disposal well, and a waste pit, all in West Texas, were analyzed by gas chromatography-mass spectrometry, inductively coupled plasma-optical emission spectroscopy, high performance liquid chromatography-high resolution mass spectrometry, high performance ion chromatography, total organic carbon/total nitrogen analysis, and pH and conductivity analysis. Several compounds known to compose hydraulic fracturing fluid were detected among two of the wastewater samples including 2-butoxyethanol, alkyl amines, and cocamide diethanolamines, toluene, and o-xylene. Due both to its quantity and quality, proper management of wastewater from UDO will be essential. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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284 KiB

Open AccessArticle

Performance Evaluation for a Contamination Detection Method Using Multiple Water Quality Sensors in an Early Warning System

by Han Che, Shuming Liu and Kate Smith

Water 2015, 7(4), 1422-1436; https://doi.org/10.3390/w7041422 - 30 Mar 2015

Cited by 13 | Viewed by 7839

Abstract

In this approach, a method utilizing data series from multivariate parameters to detect contaminant events is discussed and evaluated. Eight water quality sensors (pH, turbidity, conductivity, temperature, oxidation reduction potential, UV-254, nitrate and phosphate) are used in this study and the most commonly [...] Read more.

In this approach, a method utilizing data series from multivariate parameters to detect contaminant events is discussed and evaluated. Eight water quality sensors (pH, turbidity, conductivity, temperature, oxidation reduction potential, UV-254, nitrate and phosphate) are used in this study and the most commonly used herbicide, glyphosate, is selected as the test contaminant. Variations of all parameters are recorded in real time at different concentrations. The results from the experiment and analysis show that the proposed method with suitable optimization can detect a glyphosate contamination less than 5 min after the introduction of the contaminant using responses from online water quality sensors. The average true positive rate is 95.5%. The study also discusses the impact of the number of sensors on detection performance. The results show that if the number of sensors is reduced from 8 to 5, the true positive rate performance is still good. This indicates that the method is flexible and can be applied using a smaller number of sensors to reduce monitoring costs. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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1530 KiB

Open AccessArticle

Effect of Disc Filtration with and without Addition of Flocculent on Nano- and Micro-Particles and Their Associated Polycyclic Aromatic Hydrocarbons in Stormwater

by Katrine Nielsen, Andreas Mørch-Madsen, Peter S. Mikkelsen and Eva Eriksson

Water 2015, 7(3), 1306-1323; https://doi.org/10.3390/w7031306 - 20 Mar 2015

Cited by 9 | Viewed by 8692

Abstract

Many municipalities in Denmark and around Europe currently work towards separating stormwater and sewage. In existing urban areas this may imply disconnecting stormwater from the old combined sewer systems suffering from hydraulic overloading and discharging directly to nearby surface waters. Stormwater runoff may, [...] Read more.

Many municipalities in Denmark and around Europe currently work towards separating stormwater and sewage. In existing urban areas this may imply disconnecting stormwater from the old combined sewer systems suffering from hydraulic overloading and discharging directly to nearby surface waters. Stormwater runoff may, however, be heavily polluted and Best Available Technologies (BAT) are therefore needed to treat the stormwater before discharge. The aim here was to determine the sizes of particles found in stormwater from roads and to evaluate the use of a cationic organic flocculant to increase the size of the particles and thereby increase the removal efficiency of a 10 µm woven polyester disc filter. The samples were collected in connection with a project testing a pilot scale disc filter for treating stormwater runoff. The micro-sized particles were found to be mainly below 10 µm (6.9–19 µm) and nano-sized particles were also observed (ca. 76–228 nm). The flocculent increased the observed particle micrometer sizes by 46% and the removal of particle-associate Polycyclic Aromatic Hydrocarbons (PAHs) was confirmed. The majority of the particles were, however, still below 10 µm after addition of flocculant, which shows that application of flocculants with the woven disc filter technology for stormwater treatment needs further refinement. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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465 KiB

Open AccessArticle

Evaluation of an Ultrafiltration-Based Procedure for Simultaneous Recovery of Diverse Microbes in Source Waters

by Amy M. Kahler, Trisha B. Johnson, Donghyun Hahn, Jothikumar Narayanan, Gordana Derado and Vincent R. Hill

Water 2015, 7(3), 1202-1216; https://doi.org/10.3390/w7031202 - 18 Mar 2015

Cited by 29 | Viewed by 7232

Abstract

In this study, hollow-fiber ultrafiltration (UF) was assessed for recovery of Escherichia coli, Clostridium perfringens spores, Cryptosporidium parvum oocysts, echovirus 1, and bacteriophages MS2 and ΦX174 from ground and surface waters. Microbes were seeded into twenty-two 50-L water samples that were collected [...] Read more.

In this study, hollow-fiber ultrafiltration (UF) was assessed for recovery of Escherichia coli, Clostridium perfringens spores, Cryptosporidium parvum oocysts, echovirus 1, and bacteriophages MS2 and ΦX174 from ground and surface waters. Microbes were seeded into twenty-two 50-L water samples that were collected from the Southeastern United States and concentrated to ~500 mL by UF. Secondary concentration was performed for C. parvum by centrifugation followed by immunomagnetic separation. Secondary concentration for viruses was performed using centrifugal ultrafilters or polyethylene glycol precipitation. Nine water quality parameters were measured in each water sample to determine whether water quality data correlated with UF and secondary concentration recovery efficiencies. Average UF recovery efficiencies were 66%–95% for the six enteric microbes. Average recovery efficiencies for the secondary concentration methods were 35%–95% for C. parvum and the viruses. Overall, measured water quality parameters were not significantly associated with UF recovery efficiencies. However, recovery of ΦX174 was negatively correlated with turbidity. The recovery data demonstrate that UF can be an effective method for concentrating diverse microbes from ground and surface waters. This study highlights the utility of tangential-flow hollow fiber ultrafiltration for recovery of bacteria, viruses, and parasites from large volume environmental water samples. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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960 KiB

Open AccessArticle

The Effect of the Hydraulic Retention Time on the Performance of an Ecological Wastewater Treatment System: An Anaerobic Filter with a Constructed Wetland

by María L. Merino-Solís, Edgardo Villegas, José De Anda and Alberto López-López

Water 2015, 7(3), 1149-1163; https://doi.org/10.3390/w7031149 - 17 Mar 2015

Cited by 66 | Viewed by 11293

Abstract

This work assesses the performance of a municipal pilot wastewater treatment system employing an up-flow anaerobic filter (UAF) followed by a horizontal subsurface constructed wetland (HSSCW). This pilot scale demonstration project was implemented in a zone with subtropical climate in order to protect [...] Read more.

This work assesses the performance of a municipal pilot wastewater treatment system employing an up-flow anaerobic filter (UAF) followed by a horizontal subsurface constructed wetland (HSSCW). This pilot scale demonstration project was implemented in a zone with subtropical climate in order to protect Lake Chapala from wastewater loads that are discharged by small communities in the Lake’s vicinity. The filters were filled with tezontle as the media for biofilm support and the HSSCW was planted with two ornamental plants species, Canna hybrids and Strelitzia reginae. The experiment evaluated three hydraulic retention times (HRT) of 18, 28 and 38 h in the UAF, which corresponds to two, three and four days in HSSCW over 66 weeks. The mean efficiencies found for the complete system were 80% and 90% of BOD, 80% and 86% of COD, 30% and 33% of N_tot and between 24% and 44% of P_tot. It was possible to remove almost 80% of organic matter in 18 h in the UAF while the HSSCW reached 30% of removal for N_tot in a HRT of three days. As expected, the UAF was responsible for removing most of the organic matter and the HSSCW removed most of the nitrogen. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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1854 KiB

Open AccessArticle

Accuracy of Hourly Water Temperatures in Rivers Calculated from Air Temperatures

by Gang Chen and Xing Fang

Water 2015, 7(3), 1068-1087; https://doi.org/10.3390/w7031068 - 12 Mar 2015

Cited by 13 | Viewed by 8098

Abstract

Water temperature is a critical variable for water quality control and management. The primary objective of this paper was to develop and compare simple methods to estimate hourly water temperatures in rivers. The wave function (WF) model, originally used to calculate hourly air [...] Read more.

Water temperature is a critical variable for water quality control and management. The primary objective of this paper was to develop and compare simple methods to estimate hourly water temperatures in rivers. The wave function (WF) model, originally used to calculate hourly air temperature, was modified and applied to eight Alabama rivers. The results show significant improvement by using the modified WF model instead of direct linear and non-linear (polynomial and logistic) regression models with time lags (4–5 h). The average Nash–Sutcliffe coefficient (NS) used to evaluate model accuracy for the eight rivers improved from 0.71 for the linear model to 0.89 for the modified WF model with NS for most rivers exceeding 0.90. A lumped modified WF model was also developed by combining water temperature data for all eight rivers and can be applied for rivers in Alabama when no observed water temperatures are available to develop a site-specific WF model. The procedure to develop a modified WF model can be applied to other regions. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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348 KiB

Open AccessArticle

Influence of Temperature on the Performance of a Full-Scale Activated Sludge Process Operated at Varying Solids Retention Times Whilst Treating Municipal Sewage

by Moazzam Shahzad, Sher Jamal Khan and Parneet Paul

Water 2015, 7(3), 855-867; https://doi.org/10.3390/w7030855 - 2 Mar 2015

Cited by 24 | Viewed by 8538

Abstract

In this study, the solid retention time (SRT) was varied with the ambient temperature for a full-scale municipal activated sludge plant with capacity of 200,000 PE (Population Equivalent) located in a humid sub-tropical environment. The effects of ambient temperature on treatment performance were [...] Read more.

In this study, the solid retention time (SRT) was varied with the ambient temperature for a full-scale municipal activated sludge plant with capacity of 200,000 PE (Population Equivalent) located in a humid sub-tropical environment. The effects of ambient temperature on treatment performance were investigated. Off-line samples were collected and analyzed from the treatment plant. The actual temperature variation during the study period was divided into three overlapping ranges and the SRT was adjusted accordingly with temperature in order to achieve the desired effluent quality. The plant’s observed effluent quality and thereby its overall removal efficiency was evaluated in terms of measuring standard biochemical parameters. The results indicate that significant improvement in effluent quality can be obtained by applying the variable SRT (5–7 days) dependent on temperature variation. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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944 KiB

Open AccessArticle

Biomonitoring of Epilobium hirsutum L. Health Status to Assess Water Ecotoxicity in Constructed Wetlands Treating Mixtures of Contaminants

by Anna Guittonny-Philippe, Véronique Masotti, Jacques Rabier, Marie-Eléonore Petit, Laure Malleret, Bruno Coulomb and Isabelle Laffont-Schwob

Water 2015, 7(2), 697-715; https://doi.org/10.3390/w7020697 - 10 Feb 2015

Cited by 6 | Viewed by 6574

Abstract

For the treatment of wastewater containing organic pollutants and metals in constructed wetlands (CWs), phytoindicators may help in guiding management practices for plants and optimizing phytoremediation processes. Hairy willow-herb (Epilobium hirsutum L.) is a fast growing species commonly found in European CWs [...] Read more.

For the treatment of wastewater containing organic pollutants and metals in constructed wetlands (CWs), phytoindicators may help in guiding management practices for plants and optimizing phytoremediation processes. Hairy willow-herb (Epilobium hirsutum L.) is a fast growing species commonly found in European CWs that could constitute a suitable phytoindicator of metal toxicity. E. hirsutum was exposed for 113 days in microcosm CWs, to a metal and metalloid mixture (MPM, containing Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Sn, Zn), an organic pollutant mixture (OPM, containing hydrocarbonsC₁₀-C₄₀, phenanthrene, pyrene, anionic detergent LAS) and an organic pollutant and metal and metalloid mixture (OMPM), separately and at concentration levels mimicking levels of industrial effluents. Analyses of metal and As concentrations in biomass, and different biometric and physiological measurements were performed. Results showed that metal uptake patterns were affected by the type of pollutant mixture, resulting in variation of toxicity symptoms in E. hirsutum plants. Some of them appeared to be similar under MPM and OMPM conditions (leaf chlorosis and tip-burning, decrease of green leaf proportion), while others were characteristic of each pollutant mixture (MPM: Decrease of water content, increase of phenol content; OMPM: reduction of limb length, inhibition of vegetative reproduction, increase of chlorophyll content and Nitrogen balance index). Results emphasize the potential of E. hirsutum as a bioindicator species to be used in European CWs treating water with metal, metalloid and organic pollutants. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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Open AccessArticle

Development of a Comprehensive Fouling Model for a Rotating Membrane Bioreactor System Treating Wastewater

by Parneet Paul and Franck Anderson Jones

Water 2015, 7(2), 377-397; https://doi.org/10.3390/w7020377 - 23 Jan 2015

Cited by 9 | Viewed by 8264

Abstract

Membrane bioreactors (MBRs) are now main stream wastewater treatment technologies. In recent times, novel pressure driven rotating membrane disc modules have been specially developed that induce high shear on the membrane surface, thereby reducing fouling. Previous research has produced dead-end filtration fouling model [...] Read more.

Membrane bioreactors (MBRs) are now main stream wastewater treatment technologies. In recent times, novel pressure driven rotating membrane disc modules have been specially developed that induce high shear on the membrane surface, thereby reducing fouling. Previous research has produced dead-end filtration fouling model which combines all three classical mechanisms that was later used by another researcher as a starting point for a greatly refined model of a cross flow side-stream MBR that incorporated both hydrodynamics and soluble microbial products’ (SMP) effects. In this study, a comprehensive fouling model was created based on this earlier work that incorporated all three classical fouling mechanisms for a rotating MBR system. It was tested and validated for best fit using appropriate data sets. The initial model fit appeared good for all simulations, although it still needs to be calibrated using further appropriate data sets. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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Open AccessArticle

Monitoring of Non-Point Source Pollutions from an Agriculture Watershed in South China

by Haiying Hu and Guoru Huang

Water 2014, 6(12), 3828-3840; https://doi.org/10.3390/w6123828 - 8 Dec 2014

Cited by 23 | Viewed by 6294

Abstract

Understanding the characteristics of non-point sources (NPS) pollutions can provide theoretical support for improving water quality. Siheshui watershed located in south China was selected to explore the characteristics of NPS pollutions in rainfall-runoff process. In this small agricultural watershed, five flood events and [...] Read more.

Understanding the characteristics of non-point sources (NPS) pollutions can provide theoretical support for improving water quality. Siheshui watershed located in south China was selected to explore the characteristics of NPS pollutions in rainfall-runoff process. In this small agricultural watershed, five flood events and one non-flood event were monitored, and the water quantity and quality constituents were measured. The event mean concentrations (EMCs) of pollutant constituents in runoff flows were estimated. It is shown that the EMCs of BOD₅, COD_Mn, TSS, TP, TN, and NH₃-N in the flood events are remarkably larger than those in the non-flood event. The antecedent precipitation has a large effect on the output of the pollutant concentration. The pollutant load fluxes of most pollutant constituents change synchronously with the runoff flows, and the synchronization relationship is better than that between the pollutant concentrations and the runoff flows. The Pearson correlation analysis indicates that the EMCs of COD_Mn, TP, and TSS are significantly correlated with rainfall runoff characteristics in the flood events, while BOD₅, TN, and NH₃-N show weak correlations. In addition, the mean concentration method was used to estimate the annual NPS pollution load. It is shown that the proportions of the NPS pollution load to the total pollutant load are more than 80% from 2008 to 2010. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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Open AccessArticle

Reservoir Operation Rules for Controlling Algal Blooms in a Tributary to the Impoundment of Three Gorges Dam

by Jijian Lian, Ye Yao, Chao Ma and Qizhong Guo

Water 2014, 6(10), 3200-3223; https://doi.org/10.3390/w6103200 - 22 Oct 2014

Cited by 54 | Viewed by 10928

Abstract

Since the first impoundment of Three Gorges Dam in 2003, algal blooms occur frequently in the near-dam tributaries. It is widely recognized that the impoundment-induced change in hydrodynamic condition with the lower current velocity will make the eutrophication problem even more severe when [...] Read more.

Since the first impoundment of Three Gorges Dam in 2003, algal blooms occur frequently in the near-dam tributaries. It is widely recognized that the impoundment-induced change in hydrodynamic condition with the lower current velocity will make the eutrophication problem even more severe when an excessive amount of nutrients is already loaded into a reservoir and/or its tributaries. Operation tests carried out by Three Gorges Corporation in 2010 point to some feasible reservoir operation schemes that may have positive impacts on reducing the algal bloom level. In our study, an attempt is made to obtain, through a numerical hydrodynamic and water quality modeling and analysis, the reservoir operation rules that would reduce the level of algal blooms in the Xiangxi River (XXR), a near-dam tributary. Water movements and algal blooms in XXR are simulated and analyzed under different scenarios of one-day water discharge fluctuation or two-week water level variation. The model results demonstrate that the reservoir operations can further increase the water exchange between the mainstream of the Three Gorges Reservoir (TGR) and the XXR tributary and thus move a larger amount of algae into the deep water where it will die. Analysis of the model results indicate that the water discharge fluctuation constituted of a lower valley-load flow and a larger flow difference for the short-term operation (within a day), the rise in water level for the medium-term operation (e.g., over weeks), and the combination of the above two for the long-term operation (e.g., over months) can be the feasible reservoir operation rules in the non-flood season for TGR. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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Review

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Assessment of Agricultural Best Management Practices Using Models: Current Issues and Future Perspectives

by Hui Xie, Lei Chen and Zhenyao Shen

Water 2015, 7(3), 1088-1108; https://doi.org/10.3390/w7031088 - 12 Mar 2015

Cited by 68 | Viewed by 10682

Abstract

Best management practices (BMPs) are the most effective and practicable means to control nonpoint source (NPS) pollution at desired levels. Models are valuable tools to assess their effectiveness. Watershed managers need to choose appropriate and effective modelling methods for a given set of [...] Read more.

Best management practices (BMPs) are the most effective and practicable means to control nonpoint source (NPS) pollution at desired levels. Models are valuable tools to assess their effectiveness. Watershed managers need to choose appropriate and effective modelling methods for a given set of conditions. This paper considered state-of-the-art modelling strategies for the assessment of agricultural BMPs. Typical watershed models and specific models were analyzed in detail. Further improvements, including simplified tools, model integration, and incorporation of climate change and uncertainty analysis were also explored. This paper indicated that modelling methods are strictly scale dependent, both spatially and temporally. Despite current achievements, there is still room for future research, such as broadening the range of the pollutants considered, introducing more local BMPs, improving the representation of the functionality of BMPs, and gathering monitoring date for validation of modelled results. There is also a trend towards agricultural decision support systems (DSSs) for assessing agricultural BMPs, in which models of different scales are seamlessly integrated to bridge the scale and data gaps. This review will assist readers in model selection and development, especially those readers concerned about NPS pollution and water quality control. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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An Overview of Hybrid Water Supply Systems in the Context of Urban Water Management: Challenges and Opportunities

by Mukta Sapkota, Meenakshi Arora, Hector Malano, Magnus Moglia, Ashok Sharma, Biju George and Francis Pamminger

Water 2015, 7(1), 153-174; https://doi.org/10.3390/w7010153 - 29 Dec 2014

Cited by 75 | Viewed by 21291

Abstract

This paper presents a critical review of the physical impacts of decentralized water supply systems on existing centralized water infrastructures. This paper highlights the combination of centralized and decentralized systems, which is referred to as hybrid water supply systems. The system is hypothesized [...] Read more.

This paper presents a critical review of the physical impacts of decentralized water supply systems on existing centralized water infrastructures. This paper highlights the combination of centralized and decentralized systems, which is referred to as hybrid water supply systems. The system is hypothesized to generate more sustainable and resilient urban water systems. The basic concept is to use decentralized water supply options such as rainwater tanks, storm water harvesting and localized wastewater treatment and reuse in combination with centralized systems. Currently the impact of hybrid water supply technologies on the operational performance of the downstream infrastructure and existing treatment processes is yet to be known. The paper identifies a number of significant research gaps related to interactions between centralized and decentralized urban water services. It indicates that an improved understanding of the interaction between these systems is expected to provide a better integration of hybrid systems by improved sewerage and drainage design, as well as facilitate operation and maintenance planning. The paper also highlights the need for a framework to better understand the interaction between different components of hybrid water supply systems. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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1206 KiB

Open AccessTechnical Note

Preliminary Toxicological Evaluation of the River Danube Using in Vitro Bioassays

by Clemens Kittinger, Rita Baumert, Bettina Folli, Michaela Lipp, Astrid Liebmann, Alexander Kirschner, Andreas H. Farnleitner, Andrea J. Grisold and Gernot E. Zarfel

Water 2015, 7(5), 1959-1968; https://doi.org/10.3390/w7051959 - 30 Apr 2015

Cited by 10 | Viewed by 6200

Abstract

The Joint Danube Survey 3, carried out in 2013 was the world’s biggest river research expedition of its kind. The course of the second largest river of Europe passes large cities like Vienna, Budapest and Belgrade and is fed from many tributaries like [...] Read more.

The Joint Danube Survey 3, carried out in 2013 was the world’s biggest river research expedition of its kind. The course of the second largest river of Europe passes large cities like Vienna, Budapest and Belgrade and is fed from many tributaries like Inn, Thisza, Drava, Prut, Siret and Argeș. During the 6 weeks of shipping the 2375 km downstream the River Danube from Germany to the Black Sea an enormous number of water samples were analyzed and collected. A wide spectrum of scientific disciplines cooperated in analyzing the River Danube waters. For toxicological analysis, water samples were collected on the left, in the middle, and on the right side of the river at 68 JDS3 sampling points and frozen until the end of the Danube survey. All samples were analyzed with two in vitro bioassays tests (umuC and MTS). Testing umuC without S9 activation and MTS test did not show positive signals. But umuC investigations of the water samples came up with toxic signals on two stretches, when activated with S9 enzymes. The override of the limiting value of the umuC investigation with prior S9 activation started downstream Vienna (Austria) and was prolonged until Dunaföldvar (Hungary). This stretch of the River Danube passes a region that is highly industrialized, intensively used for agricultural purposes and also highly populated (Vienna, Bratislava and Budapest). The elevated values may indicate these influences. Full article

(This article belongs to the Special Issue Water Quality Control and Management)

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