International Journal of Environmental Research and Public Health

Research

10 pages, 1323 KiB

Open AccessArticle

Enhancement of COD Removal from Oilfield Produced Wastewater by Combination of Advanced Oxidation, Adsorption and Ultrafiltration

by Xiaodong Dai, Jian Fang, Lei Li, Yan Dong and Jianhua Zhang

Int. J. Environ. Res. Public Health 2019, 16(17), 3223; https://doi.org/10.3390/ijerph16173223 - 3 Sep 2019

Cited by 18 | Viewed by 3486

Abstract

The wastewater produced from the oilfield is chemically corrosive due to high salinity in combination with high temperatures. It is also rich in contaminants, such as oil, polyacrylamide, emulsions, suspended solid, etc. The density difference between the oil and water in the wastewater [...] Read more.

The wastewater produced from the oilfield is chemically corrosive due to high salinity in combination with high temperatures. It is also rich in contaminants, such as oil, polyacrylamide, emulsions, suspended solid, etc. The density difference between the oil and water in the wastewater is low, which makes separation via gravity difficult. In this study, a combined pilot treatment is studied, which includes Fenton oxidation, settlement, activated carbon adsorption, and ultrafiltration (UF). The operational conditions of Fenton oxidation are optimized based on alleviating the fouling of the UF membrane. When the Fenton oxidation was operated at the molar ratio of H₂O₂ to FeSO₄ 3:1 and pH 2.2–2.5, the UF membrane could operate continuously for 20 h without cleaning. The membrane was fouled by the organics (oil/grease) and polymer, which can be effectively removed by composite cleaning reagent consisting of 0.1% NaOH and 0.1% sodium dodecylbenzenesulfonate (SDBS). With the UF treatment, the chemical oxygen demand (COD) of the effluent was less than 50 mg/L, which could meet the upgraded standard. Full article

(This article belongs to the Special Issue Membrane Technologies for Water and Wastewater Treatment)

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15 pages, 6275 KiB

Open AccessFeature PaperArticle

Investigation into Micropollutant Removal from Wastewaters by a Membrane Bioreactor

by Mohanad Kamaz, S. Ranil Wickramasinghe, Satchithanandam Eswaranandam, Wen Zhang, Steven M. Jones, Michael J. Watts and Xianghong Qian

Int. J. Environ. Res. Public Health 2019, 16(8), 1363; https://doi.org/10.3390/ijerph16081363 - 16 Apr 2019

Cited by 33 | Viewed by 4072

Abstract

Direct potable reuse of wastewater is attractive as the demand for potable water increases. However, the presence of organic micropollutants in industrial and domestic wastewater is a major health and environmental concern. Conventional wastewater treatment processes are not designed to remove these compounds. [...] Read more.

Direct potable reuse of wastewater is attractive as the demand for potable water increases. However, the presence of organic micropollutants in industrial and domestic wastewater is a major health and environmental concern. Conventional wastewater treatment processes are not designed to remove these compounds. Further many of these emerging pollutants are not regulated. Membrane bioreactor based biological wastewater treatment has recently become a preferred method for treating municipal and other industrial wastewaters. Here the removal of five selected micropollutants representing different classes of emerging micropollutants has been investigated using a membrane bioreactor. Acetaminophen, amoxicillin, atrazine, estrone, and triclosan were spiked into wastewaters obtained from a local wastewater treatment facility prior to introduction to the membrane bioreactor containing both anoxic and aerobic tanks. Removal of these compounds by adsorption and biological degradation was determined for both the anoxic and aerobic processes. The removal as a function of operating time was investigated. The results obtained here suggest that removal may be related to the chemical structure of the micropollutants. Full article

(This article belongs to the Special Issue Membrane Technologies for Water and Wastewater Treatment)

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11 pages, 2991 KiB

Open AccessArticle

Newly Designed Hydrolysis Acidification Flat-Sheet Ceramic Membrane Bioreactor for Treating High-Strength Dyeing Wastewater

by Yue Jin, Dunqiu Wang and Wenjie Zhang

Int. J. Environ. Res. Public Health 2019, 16(5), 777; https://doi.org/10.3390/ijerph16050777 - 4 Mar 2019

Cited by 8 | Viewed by 3321

Abstract

Cost-effective treatment of dyeing wastewater remains a challenge. In this study, a newly designed hydrolysis acidification flat-sheet ceramic membrane bioreactor (HA-CMBR) was used in treating high-strength dyeing wastewater. The start-up phase of the HA-CMBR was accomplished in 29 days by using cultivated seed [...] Read more.

Cost-effective treatment of dyeing wastewater remains a challenge. In this study, a newly designed hydrolysis acidification flat-sheet ceramic membrane bioreactor (HA-CMBR) was used in treating high-strength dyeing wastewater. The start-up phase of the HA-CMBR was accomplished in 29 days by using cultivated seed sludge. Chemical oxygen demand (COD) removal rate reached about 62% with influent COD of 7800 mg/L and an organic loading rate of 7.80 kg-COD/(m³·d). Chromaticity removal exceeded 99%. The results show that the HA-CMBR has good removal performance in treating dyeing wastewater. The HA-CMBR could run with low energy consumption at trans-membrane pressure (TMP) <10 kPa due to the good water permeability of the flat-sheet ceramic membrane. New strains with 92%–96% similarity to Alkalibaculum bacchi, Pseudomonas sp., Desulfovibrio sp., and Halothiobacillaceae were identified in the HA-CMBR. Microbial population analysis indicated that Desulfovibrio sp., Deltaproteobacteria, Halothiobacillaceae, Alkalibaculum sp., Pseudomonas sp., Desulfomicrobium sp., and Chlorobaculum sp. dominated in the HA-CMBR. Full article

(This article belongs to the Special Issue Membrane Technologies for Water and Wastewater Treatment)

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12 pages, 2715 KiB

Open AccessArticle

Surface Modification of PVDF Membranes for Treating Produced Waters by Direct Contact Membrane Distillation

by Mohanad Kamaz, Arijit Sengupta, Ashley Gutierrez, Yu-Hsuan Chiao and Ranil Wickramasinghe

Int. J. Environ. Res. Public Health 2019, 16(5), 685; https://doi.org/10.3390/ijerph16050685 - 26 Feb 2019

Cited by 36 | Viewed by 5476

Abstract

Direct contact membrane distillation (DCMD) has been conducted to treat hydraulic fracturing-produced water using polyvinylidenedifluoride (PVDF) membranes. Tailoring the surface properties of the membrane is critical in order to reduce the rate of adsorption of dissolved organic species as well as mineral salts. [...] Read more.

Direct contact membrane distillation (DCMD) has been conducted to treat hydraulic fracturing-produced water using polyvinylidenedifluoride (PVDF) membranes. Tailoring the surface properties of the membrane is critical in order to reduce the rate of adsorption of dissolved organic species as well as mineral salts. The PVDF membranes have been modified by grafting zwitterion and polyionic liquid-based polymer chains. In addition, surface oxidation of the PVDF membrane has been conducted using KMnO₄ and NaOH. Surface modification conditions were chosen in order to minimize the decrease in contact angle. Thus, the membranes remain hydrophobic, essential for suppression of wetting. DCMD was conducted using the base PVDF membrane as well as modified membranes. In addition, DCMD was conducted on the base membrane using produced water (PW) that was pretreated by electrocoagulation to remove dissolved organic compounds. After DCMD all membranes were analyzed by scanning electron microscopy imaging as well as Energy-Dispersive X-Ray spectroscopy. Surface modification led to a greater volume of PW being treated by the membrane prior to drastic flux decline. The results indicate that tailoring the surface properties of the membrane enhances fouling resistance and could reduce pretreatment requirements. Full article

(This article belongs to the Special Issue Membrane Technologies for Water and Wastewater Treatment)

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12 pages, 5204 KiB

Open AccessArticle

New Polymer Inclusion Membrane Containing β-Cyclodextrin Polymer: Application for Pharmaceutical Pollutant Removal from Waste Water

by Lamia Moulahcene, Mohamed Skiba, Frederic Bounoure, Mohamed Benamor, Nicolas Milon, Francois Hallouard and Malika Lahiani-Skiba

Int. J. Environ. Res. Public Health 2019, 16(3), 414; https://doi.org/10.3390/ijerph16030414 - 31 Jan 2019

Cited by 26 | Viewed by 4203

Abstract

We present herein the preparation of novel polymer inclusion membranes (PIMs) containing insoluble β-CD polymer as a carrier, polyvinyl chloride as a base polymer, and dibuthylphtalate (DBP) as a plasticizer in varying proportions. The prepared PIMs can be obtained by a simple, fast, [...] Read more.

We present herein the preparation of novel polymer inclusion membranes (PIMs) containing insoluble β-CD polymer as a carrier, polyvinyl chloride as a base polymer, and dibuthylphtalate (DBP) as a plasticizer in varying proportions. The prepared PIMs can be obtained by a simple, fast, and high-yield preparation process. Physicochemical characterizations of such membranes occurred in a homogeneous structure. In addition, Fourier-transform infrared Spectroscopy (FT-IR) analysis found that DBP was inserted between these polymeric chains by non-covalent interactions. This led to a spacing of PVC/poly(β-cyclodextrin) chains inducing a better access of guest molecules to PIM cyclodextrins. To achieve the elimination of ibuprofen and progesterone, two examples of emerging environmental contaminants that can lead to possible alterations to aquatic environments and affect human health, the effect of three operating parameters was studied (pH, the proportion of β-cyclodextrin polymer, and wastewater agitation). The proportion of β-cyclodextrin polymer and wastewater agitation had a favorable influence on drug extraction at 10 ppm. The PIMs containing β-cyclodextrin polymer was unstable in basic conditions and was more effective at acidic pH. These initial results demonstrate the high potential for drug extraction of this polymer. Full article

(This article belongs to the Special Issue Membrane Technologies for Water and Wastewater Treatment)

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11 pages, 2707 KiB

Open AccessFeature PaperArticle

Biofouling Mitigation by Chloramination during Forward Osmosis Filtration of Wastewater

by Takahiro Fujioka, Kha H. Nguyen, Anh Tram Hoang, Tetsuro Ueyama, Hidenari Yasui, Mitsuharu Terashima and Long D. Nghiem

Int. J. Environ. Res. Public Health 2018, 15(10), 2124; https://doi.org/10.3390/ijerph15102124 - 27 Sep 2018

Cited by 8 | Viewed by 4205

Abstract

Pre-concentration is essential for energy and resource recovery from municipal wastewater. The potential of forward osmosis (FO) membranes to pre-concentrate wastewater for subsequent biogas production has been demonstrated, although biofouling has also emerged as a prominent challenge. This study, using a cellulose triacetate [...] Read more.

Pre-concentration is essential for energy and resource recovery from municipal wastewater. The potential of forward osmosis (FO) membranes to pre-concentrate wastewater for subsequent biogas production has been demonstrated, although biofouling has also emerged as a prominent challenge. This study, using a cellulose triacetate FO membrane, shows that chloramination of wastewater in the feed solution at 3–8 mg/L residual monochloramine significantly reduces membrane biofouling. During a 96-h pre-concentration, flux in the chloraminated FO system decreased by only 6% and this flux decline is mostly attributed to the increase in salinity (or osmotic pressure) of the feed due to pre-concentration. In contrast, flux in the non-chloraminated FO system dropped by 35% under the same experimental conditions. When the feed was chloraminated, the number of bacterial particles deposited on the membrane surface was significantly lower compared to a non-chloraminated wastewater feed. This study demonstrated, for the first time, the potential of chloramination to inhibit bacteria growth and consequently biofouling during pre-concentration of wastewater using a FO membrane. Full article

(This article belongs to the Special Issue Membrane Technologies for Water and Wastewater Treatment)

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16 pages, 3478 KiB

Open AccessFeature PaperArticle

Removal Characteristics of N-Nitrosamines and Their Precursors by Pilot-Scale Integrated Membrane Systems for Water Reuse

by Haruka Takeuchi, Naoyuki Yamashita, Norihide Nakada and Hiroaki Tanaka

Int. J. Environ. Res. Public Health 2018, 15(9), 1960; https://doi.org/10.3390/ijerph15091960 - 7 Sep 2018

Cited by 20 | Viewed by 4710

Abstract

This study investigated the removal characteristics of N-Nitrosamines and their precursors at three pilot-scale water reclamation plants. These plants applies different integrated membrane systems: (1) microfiltration (MF)/nanofiltration (NF)/reverse osmosis (RO) membrane; (2) sand filtration/three-stage RO; and (3) ultrafiltration (UF)/NF and UF/RO. Variable [...] Read more.

This study investigated the removal characteristics of N-Nitrosamines and their precursors at three pilot-scale water reclamation plants. These plants applies different integrated membrane systems: (1) microfiltration (MF)/nanofiltration (NF)/reverse osmosis (RO) membrane; (2) sand filtration/three-stage RO; and (3) ultrafiltration (UF)/NF and UF/RO. Variable removal of N-Nitrosodimethylamine (NDMA) by the RO processes could be attributed to membrane fouling and the feed water temperature. The effect of membrane fouling on N-Nitrosamine removal was extensively evaluated at one of the plants by conducting one month of operation and chemical cleaning of the RO element. Membrane fouling enhanced N-Nitrosamine removal by the pilot-scale RO process. This finding contributes to better understanding of the variable removal of NDMA by RO processes. This study also investigated the removal characteristics of N-Nitrosamine precursors. The NF and RO processes greatly reduced NDMA formation potential (FP), but the UF process had little effect. The contributions of MF, NF, and RO processes for reducing FPs of NDMA, N-Nitrosopyrrolidine and N-Nitrosodiethylamine were different, suggesting different size distributions of their precursors. Full article

(This article belongs to the Special Issue Membrane Technologies for Water and Wastewater Treatment)

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18 pages, 1377 KiB

Open AccessFeature PaperArticle

Study of Hybrid PVA/MA/TEOS Pervaporation Membrane and Evaluation of Energy Requirement for Desalination by Pervaporation

by Zongli Xie, Derrick Ng, Manh Hoang, Jianhua Zhang and Stephen Gray

Int. J. Environ. Res. Public Health 2018, 15(9), 1913; https://doi.org/10.3390/ijerph15091913 - 3 Sep 2018

Cited by 31 | Viewed by 5213

Abstract

Desalination by pervaporation is a membrane process that is yet to be realized for commercial application. To investigate the feasibility and viability of scaling up, a process engineering model was developed to evaluate the energy requirement based on the experimental study of a [...] Read more.

Desalination by pervaporation is a membrane process that is yet to be realized for commercial application. To investigate the feasibility and viability of scaling up, a process engineering model was developed to evaluate the energy requirement based on the experimental study of a hybrid polyvinyl alcohol/maleic acid/tetraethyl orthosilicate (PVA/MA/TEOS) Pervaporation Membrane. The energy consumption includes the external heating and cooling required for the feed and permeate streams, as well as the electrical power associated with pumps for re-circulating feed and maintaining vacuum. The thermal energy requirement is significant (e.g., up to 2609 MJ/m³ of thermal energy) and is required to maintain the feed stream at 65 °C in recirculation mode. The electrical energy requirement is very small (<0.2 kWh/m³ of required at 65 °C feed temperature at steady state) with the vacuum pump contributing to the majority of the electrical energy. The energy required for the pervaporation process was also compared to other desalination processes such as Reverse Osmosis (RO), Multi-stage Flash (MSF), and Multiple Effect Distillation (MED). The electrical energy requirement for pervaporation is the lowest among these desalination technologies. However, the thermal energy needed for pervaporation is significant. Pervaporation may be attractive when the process is integrated with waste heat and heat recovery option and used in niche applications such as RO brine concentration or salt recovery. Full article

(This article belongs to the Special Issue Membrane Technologies for Water and Wastewater Treatment)

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14 pages, 10190 KiB

Open AccessFeature PaperArticle

Surface Oxidation of Ethylenechlorotrifluoroethylene (ECTFE) Membrane for the Treatment of Real Produced Water by Membrane Distillation

by Zahra Anari, Arijit Sengupta and Sumith Ranil Wickramasinghe

Int. J. Environ. Res. Public Health 2018, 15(8), 1561; https://doi.org/10.3390/ijerph15081561 - 24 Jul 2018

Cited by 17 | Viewed by 4175

Abstract

Modification of ethyleneechlorotrifluoroethylene (ECTFE) membranes by simple surface oxidation was reported in the present investigation in order to induce thin hydrophilic layer on hydrophobic membrane surface for the treatment of real produced water (PW). FTIR spectra indicates the appearance of hydrophilic functional groups [...] Read more.

Modification of ethyleneechlorotrifluoroethylene (ECTFE) membranes by simple surface oxidation was reported in the present investigation in order to induce thin hydrophilic layer on hydrophobic membrane surface for the treatment of real produced water (PW). FTIR spectra indicates the appearance of hydrophilic functional groups (–OH and –COOH) on the membrane surface due to modification, while water contact angle, zeta potential measurement, EDX, XPS analysis confirmed the presence of O functionalized hydrophilic groups on the surface. The effect of modification temperature and the time of surface oxidation on the performance of the resulting membranes were studied systematically, which revealed that induction of optimized hydrophilicity can successfully reduce the organic fouling. However, too much hydrophilic surface induces polar/electrostatic interaction resulting salt deposition on membrane surface. A simple on site cleaning procedure was demonstrated to be successful for the treatment PW for at least three consecutive cycles of membrane distillation (MD). Full article

(This article belongs to the Special Issue Membrane Technologies for Water and Wastewater Treatment)

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16 pages, 1094 KiB

Open AccessArticle

Quorum Sensing versus Quenching Bacterial Isolates Obtained from MBR Plants Treating Leachates from Municipal Solid Waste

by Albert Soler, Lucía Arregui, Miguel Arroyo, José Antonio Mendoza, Andrea Muras, Cristina Álvarez, Cristina García-Vera, Domingo Marquina, Antonio Santos and Susana Serrano

Int. J. Environ. Res. Public Health 2018, 15(5), 1019; https://doi.org/10.3390/ijerph15051019 - 18 May 2018

Cited by 16 | Viewed by 4655

Abstract

Quorum sensing (QS) is a mechanism dependent on bacterial density. This coordinated process is mediated by the synthesis and the secretion of signal molecules, called autoinducers (AIs). N-acyl-homoserine lactones (AHLs) are the most common AIs that are used by Gram-negative bacteria and [...] Read more.

Quorum sensing (QS) is a mechanism dependent on bacterial density. This coordinated process is mediated by the synthesis and the secretion of signal molecules, called autoinducers (AIs). N-acyl-homoserine lactones (AHLs) are the most common AIs that are used by Gram-negative bacteria and are involved in biofilm formation. Quorum Quenching (QQ) is the interference of QS by producing hydrolyzing enzymes, among other strategies. The main objective of the present study was to identify QS and QQ strains from MBR wastewater treatment plants. A total of 99 strains were isolated from two Spanish plants that were intended to treat leachate from municipal solid waste. Five AHL producers were detected using AHL biosensor strains (Chromobacterium violaceum CV026 and Agrobacterium tumefaciens NT1). Fifteen strains of seventy-one Gram-positive were capable of eliminating or reducing at least one AHL activity. The analysis of 16S rRNA gene sequence showed the importance of the Pseudomonas genus in the production of biofilms and the relevance of the genus Bacillus in the disruption of the QS mechanism, in which the potential activity of lactonase or acylase enzymes was investigated with the aim to contribute to solve biofouling problems and to increase the useful lifespan of membranes. Full article

(This article belongs to the Special Issue Membrane Technologies for Water and Wastewater Treatment)

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12 pages, 1387 KiB

Open AccessFeature PaperArticle

Water Reclamation Using a Ceramic Nanofiltration Membrane and Surface Flushing with Ozonated Water

by Takahiro Fujioka, Anh T. Hoang, Tetsuji Okuda, Haruka Takeuchi, Hiroaki Tanaka and Long D. Nghiem

Int. J. Environ. Res. Public Health 2018, 15(4), 799; https://doi.org/10.3390/ijerph15040799 - 19 Apr 2018

Cited by 16 | Viewed by 6322

Abstract

A new membrane fouling control technique using ozonated water flushing was evaluated for direct nanofiltration (NF) of secondary wastewater effluent using a ceramic NF membrane. Experiments were conducted at a permeate flux of 44 L/m²h to evaluate the ozonated water flushing [...] Read more.

A new membrane fouling control technique using ozonated water flushing was evaluated for direct nanofiltration (NF) of secondary wastewater effluent using a ceramic NF membrane. Experiments were conducted at a permeate flux of 44 L/m²h to evaluate the ozonated water flushing technique for fouling mitigation. Surface flushing with clean water did not effectively remove foulants from the NF membrane. In contrast, surface flushing with ozonated water (4 mg/L dissolved ozone) could effectively remove most foulants to restore the membrane permeability. This surface flushing technique using ozonated water was able to limit the progression of fouling to 35% in transmembrane pressure increase over five filtration cycles. Results from this study also heighten the need for further development of ceramic NF membrane to ensure adequate removal of pharmaceuticals and personal care products (PPCPs) for water recycling applications. The ceramic NF membrane used in this study showed approximately 40% TOC rejection, and the rejection of PPCPs was generally low and highly variable. It is expected that the fouling mitigation technique developed here is even more important for ceramic NF membranes with smaller pore size and thus better PPCP rejection. Full article

(This article belongs to the Special Issue Membrane Technologies for Water and Wastewater Treatment)

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