Special Issue "Water Quality Engineering and Wastewater Treatment"

A special issue of Water (ISSN 2073-4441). This special issue belongs to the section "Wastewater Treatment and Reuse".

Deadline for manuscript submissions: closed (31 December 2020).

Special Issue Editors

Prof. Dr. Yung-Tse Hung
E-Mail Website
Guest Editor
Department of Civil and Environmental Engineering, Cleveland State University, Cleveland, OH 44115, USA
Interests: water supply and water treatment; municipal wastewater treatment; industrial waste treatment; biological waste treatment; water and wastewater treatment plant design; water pollution control; water quality engineering
Special Issues and Collections in MDPI journals
Prof. Dr. Hamidi Abdul Aziz
E-Mail Website
Guest Editor
School of Civil Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia
Interests: water supply and water treatment, municipal wastewater treatment, industrial waste treatment, biological waste treatment, water and wastewater treatment plant design, water pollution control, water quality engineering
Special Issues and Collections in MDPI journals
Prof. Dr. Issam A. Al-Khatib
E-Mail Website
Guest Editor
Institute of Environmental and Water Studies Faculty of Graduate Studies Birzeit University, west Bank, Palestine
Interests: water recourses management and quality, environmental assessment, wastewater management, advocacy, coordination and networking
Special Issues and Collections in MDPI journals
Dr. Rehab O. Abdel Rahman
E-Mail Website
Guest Editor
Associate Professor, Hot Lab. & Waste Manag. Center, Atomic Energy Authority of Egypt, Inshas, P.O. 13759 Cairo, Egypt
Interests: radioactive waste management, wastewater treatment, natural and synthetic materials assessments, pollution control
Dr. Mario GR Cora-Hernandez
E-Mail Website
Guest Editor
Adjunct Associate Professor, School of Undergraduate Studies, Sciences Program, University of Maryland University College, 3501 University Blvd East, Adelphi, MD, 20783, USA
Interests: industrial and municipal wastewater treatment, waste treatment, industrial hygiene, environmental management and sustainability, and air pollution control

Special Issue Information

Dear Colleagues,

Clean water is one of the most important natural resources on earth. Wastewater, which is spent water, is also a valuable natural resource in the world. However, wastewater may contain many contaminants and cannot be released back into the environment until the contaminants are removed. Untreated wastewater and inadequately treated wastewater may have a detrimental effect on the environment and a harmful effect on human health. Water quality engineering addresses the sources, transport, and treatment of chemical and microbiological contaminants that affect water. Our objective is the treatment of wastewater so that the treated wastewater can meet national effluent standards for the protection of the environment and the protection of public health.

This Special Issue aims to seek contributions on advanced technologies applied to the treatment of municipal and industrial wastewater and sludge. We seek contributions that deal with recent advances in municipal wastewater, industrial wastewater, and sludge-treatment technologies; the health effects of municipal wastewater; risk management; energy-efficient wastewater treatment; water sustainability; and water reuse and resource recovery.

Prof. Dr. Yung-Tse Hung
Prof. Dr. Hamidi Abdul Aziz
Prof. Dr. Issam A. Al-Khatib
Dr. Rehab O. Abdel Rahman
Dr. Mario GR Cora-Hernandez
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Water is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2000 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • advanced wastewater technology
  • onsite wastewater treatment
  • natural wastewater treatment system
  • biological treatment
  • physicochemical treatment
  • tertiary treatment
  • water quality
  • sludge treatment and disposal
  • energy-efficient wastewater treatment
  • water reuse
  • resource recovery
  • municipal wastewater
  • industrial wastewater
  • nutrient removal

Published Papers (19 papers)

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Editorial

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Open AccessEditorial
Water Quality Engineering and Wastewater Treatment
Water 2021, 13(3), 330; https://doi.org/10.3390/w13030330 - 29 Jan 2021
Viewed by 383
Abstract
Wastewater treatment is crucial to prevent environmental pollution [...] Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)

Research

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Open AccessArticle
Evaluating the Effect of pH, Temperature, and Hydraulic Retention Time on Biological Sulphate Reduction Using Response Surface Methodology
Water 2020, 12(10), 2662; https://doi.org/10.3390/w12102662 - 23 Sep 2020
Cited by 2 | Viewed by 513
Abstract
Biological sulphate reduction (BSR) has been identified as a promising alternative for treating acid mine drainage. In this study, the effect of pH, temperature, and hydraulic retention time (HRT) on BSR was investigated. The Box–Behnken design was used to matrix independent variables, namely [...] Read more.
Biological sulphate reduction (BSR) has been identified as a promising alternative for treating acid mine drainage. In this study, the effect of pH, temperature, and hydraulic retention time (HRT) on BSR was investigated. The Box–Behnken design was used to matrix independent variables, namely pH (4–6), temperature (10–30 °C), and HRT (2–7 days) with the sulphate reduction efficiency and sulphate reduction rate as response variables. Experiments were conducted in packed bed reactors operating in a downflow mode. Response surface methodology was used to statistically analyse the data and to develop statistical models that can be used to fully understand the individual effects and the interactions between the independent variables. The analysis of variance results showed that the data fitted the quadratic models well as confirmed by a non-significant lack of fit. The temperature and HRT effect were significant (p < 0.0001), and these two variables had a strong interaction. However, the influence of pH was insignificant (p > 0.05). Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)
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Open AccessArticle
The Fate of Anthropogenic Nanoparticles, nTiO2 and nCeO2, in Waste Water Treatment
Water 2020, 12(9), 2509; https://doi.org/10.3390/w12092509 - 09 Sep 2020
Cited by 3 | Viewed by 773
Abstract
Wastewater treatment is one of the main end-of-life scenarios, as well as a possible reentry point into the environment, for anthropogenic nanoparticles (NP). These can be released from consumer products such as sunscreen or antibacterial clothing, from health-related applications or from manufacturing processes [...] Read more.
Wastewater treatment is one of the main end-of-life scenarios, as well as a possible reentry point into the environment, for anthropogenic nanoparticles (NP). These can be released from consumer products such as sunscreen or antibacterial clothing, from health-related applications or from manufacturing processes such as the use of polishing materials (nCeO2) or paints (nTiO2). The use of NP has dramatically increased over recent years and initial studies have examined the possibility of toxic or environmentally hazardous effects of these particles, as well as their behavior when released. This study focuses on the fate of nTiO2 and nCeO2 during the wastewater treatment process using lab scale wastewater treatment systems to simulate the NP mass flow in the wastewater treatment process. The feasibility of single particle mass spectroscopy (sp-ICP-MS) was tested to determine the NP load. The results show that nTiO2 and nCeO2 are adsorbed to at least 90 percent of the sludge. Furthermore, the results indicate that there are processes during the passage of the treatment system that lead to a modification of the NP shape in the effluent, as NP are observed to be partially smaller in effluent than in the added solution. This observation was made particularly for nCeO2 and might be due to dissolution processes or sedimentation of larger particles during the passage of the treatment system. Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)
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Open AccessArticle
Lemna minor Bioassay Evaluation Using Computer Image Analysis
Water 2020, 12(8), 2207; https://doi.org/10.3390/w12082207 - 05 Aug 2020
Cited by 2 | Viewed by 775
Abstract
This article deals with using computer vision in the evaluation of the Lemna minor bioassay. According to the conventional method, the growth of Lemna minor mass is determined from the number of leaves grown. In this work, instead of counting individual leaves, we [...] Read more.
This article deals with using computer vision in the evaluation of the Lemna minor bioassay. According to the conventional method, the growth of Lemna minor mass is determined from the number of leaves grown. In this work, instead of counting individual leaves, we propose measuring the area occupied by the leaves using computer vision and compare the new approach with the conventional one. The bioassay is performed according to the ISO 20079 standard as a 168 h growth inhibition test; the aim of the experiment was to quantify the negative effects on the vegetative growth using two parameters—the number of leaves and the area occupied by the leaves. The method based on image processing was faster and also more precise since it enabled us to detect the negative effect of the tested substance on leave size, not only on their number. It can be concluded that the toxic effect has shown to be more significant when considering the leaves area rather than the number of leaves. Moreover, mistakes caused by human factor during leaves counting are eliminated using the computer vision based method. Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)
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Open AccessArticle
pH-Dependent Degradation of Diclofenac by a Tunnel-Structured Manganese Oxide
Water 2020, 12(8), 2203; https://doi.org/10.3390/w12082203 - 05 Aug 2020
Cited by 1 | Viewed by 781
Abstract
The mechanism of diclofenac (DIC) degradation by tunnel-structured γ-MnO2, with superior oxidative and catalytic abilities, was determined in terms of solution pH. High-performance liquid chromatography with mass spectroscopy (HPLC–MS) was used to identify intermediates and final products of DIC degradation. DIC [...] Read more.
The mechanism of diclofenac (DIC) degradation by tunnel-structured γ-MnO2, with superior oxidative and catalytic abilities, was determined in terms of solution pH. High-performance liquid chromatography with mass spectroscopy (HPLC–MS) was used to identify intermediates and final products of DIC degradation. DIC can be efficiently oxidized by γ-MnO2 in an acidic medium, and the removal rate decreased significantly under neutral and alkaline conditions. The developed model can successfully fit DIC degradation kinetics and demonstrates electron transfer control under acidic conditions and precursor complex formation control mechanism under neutral to alkaline conditions, in which the pH extent for two mechanisms exactly corresponds to the distribution percentage of ionized species of DIC. We also found surface reactive sites (Srxn), a key parameter in the kinetic model for mechanism determination, to be exactly a function of solution pH and MnO2 dosage. The main products of oxidation with a highly active hydroxylation pathway on the tunnel-structured Mn-oxide are 5-iminoquinone DIC, hydroxyl-DIC, and 2,6-dichloro-N-o-tolylbenzenamine. Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)
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Open AccessArticle
Kinetic and Prediction Modeling Studies of Organic Pollutants Removal from Municipal Wastewater using Moringa oleifera Biomass as a Coagulant
Water 2020, 12(7), 2052; https://doi.org/10.3390/w12072052 - 19 Jul 2020
Cited by 6 | Viewed by 1043
Abstract
This study investigated the potential of Moringa oleifera (MO) seed biomass as a coagulant for the removal of turbidity, biochemical oxygen demand (BOD), and chemical oxygen demand (COD) of municipal wastewater. Triplicated laboratory experiments using MO coagulant added at varying treatment dosages of [...] Read more.
This study investigated the potential of Moringa oleifera (MO) seed biomass as a coagulant for the removal of turbidity, biochemical oxygen demand (BOD), and chemical oxygen demand (COD) of municipal wastewater. Triplicated laboratory experiments using MO coagulant added at varying treatment dosages of 50, 100, 150, 200 mg/L, and a control (0 mg/L) treatment were performed for a settling period of 250 min at room temperature. Kinetics and prediction variables of cumulative turbidity, BOD, and COD removal were estimated using simplified first order and modified Gompertz models. Results showed that the maximum removal of turbidity, BOD, and COD were 94.44%, 68.72%, and 57.61%, respectively, using an MO dose of 150 mg/L. Various kinetic parameters, such as rate constant (r), measured (REm) versus predicted (REp) cumulative removal, and specific pollutant removal rate (µm), were also maximum when an MO dose of 150 mg/L was added, the standard error being below 5%. The developed models were successfully validated over multiple observations. This study suggests low cost and sustainable removal of turbidity, BOD, and COD of municipal wastewater using MO seed biomass as a coagulant. Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)
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Open AccessArticle
Evaluation of Groundwater and Grey Water Contamination with Heavy Metals and Their Adsorptive Remediation Using Renewable Carbon from a Mixed-Waste Source
Water 2020, 12(6), 1802; https://doi.org/10.3390/w12061802 - 24 Jun 2020
Cited by 1 | Viewed by 767
Abstract
The contamination of water sources with heavy metals is a serious challenge that humanity is facing worldwide. The aim of this work was to evaluate and remediate the metal pollution in groundwater and greywater resources from Riyadh, Saudi Arabia. In addition, we investigated [...] Read more.
The contamination of water sources with heavy metals is a serious challenge that humanity is facing worldwide. The aim of this work was to evaluate and remediate the metal pollution in groundwater and greywater resources from Riyadh, Saudi Arabia. In addition, we investigated the application of ultrasonic power before adsorption to assess the dispersion of renewable carbon from mixed-waste sources (RC-MWS) as an adsorbent and enhance the water purification process. The renewable carbon adsorbent showed high ability to adsorb Pb(II), Zn(II), Cu(II), and Fe(II) from samples of the actual water under study. The conditions for the remediation of water polluted with heavy metals by adsorptive-separation were investigated, including the pH of the adsorption solution, the concentration of the heavy metal(s) under study, and the competition at the adsorption sites. The enhanced adsorption process exhibited the best performance at a pH of 6 and room temperature, and with a contact time of 60 min. Kinetic studies showed that the pseudo-second-order kinetic model was fitted with the adsorption of Pb(II), Zn(II), Cu(II), and Fe(II) onto the RC-MWS. The adsorption data were well fitted by Langmuir isotherms. The Freundlich isotherm was slightly fitted in the cases of Cu(II), Zn(II), and Fe(II), but not in the cases of Pb(II). The developed adsorption process was successfully applied to actual water samples, including water samples from Deria and Mozahemia and samples from clothes and car washing centers in Riyadh city. Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)
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Open AccessFeature PaperEditor’s ChoiceArticle
Reasons of Acceptance and Barriers of House Onsite Greywater Treatment and Reuse in Palestinian Rural Areas
Water 2020, 12(6), 1679; https://doi.org/10.3390/w12061679 - 11 Jun 2020
Cited by 1 | Viewed by 988
Abstract
In the last twenty years, house onsite wastewater management systems have been increasing in the West Bank’s rural areas. The aim of this research was to reveal, in the context of providing onsite Grey Water Treatment Plants (GWTPs) for wastewater management in the [...] Read more.
In the last twenty years, house onsite wastewater management systems have been increasing in the West Bank’s rural areas. The aim of this research was to reveal, in the context of providing onsite Grey Water Treatment Plants (GWTPs) for wastewater management in the rural communities in Palestine, the local population’s perceptions, in the sense of acceptance of and barriers towards such a type of wastewater management, so as to figure out successes, failures and lessons. The data collection tool was a questionnaire that targeted the households served with GWTPs. The findings show that 13% of the total constructed treatment plants were not operative. The most important barrier as mentioned by 66.5% is odor emission and insect infestation. Then, 25.1% of the implementing agencies never monitor or check the treatment plants, and 59.3% of them monitor and check the plants only during the first 2–3 months. The next barrier is inadequate beneficiary experience in operation and maintenance. Health concerns regarding quality of crops irrigated by treated grey water were another barrier. The results revealed that the reuse of treated grey water in irrigation was the main incentive for GWTPs as stated by 88.0% of beneficiaries. The second incentive was the saving of cesspit discharge frequency and its financial consequences, as stated by 71.3%. Finally, 72.5% of the beneficiaries stated that they had a water shortage before implementing GWTPs, and the GWTPs contributed to solving it. The highest percentage (82.6%) of beneficiaries accepted the treatment units because of their willingness to reuse treated water for irrigation and agricultural purposes. Education level has an impact on GWTP acceptance, with 73% of not educated beneficiaries being satisfied and 58.8% of educated people being satisfied. Islamic religion is considered a driver for accepting reuse of treated grey water in irrigation, according to the majority of people (70%). Women play a major role on GWTP management; 68.9% of the treatment systems are run by men side-by-side with women (fathers and mothers), and 24% are run completely by women. The majority of GWTP beneficiaries (70.4%) are satisfied with GWTPs. Little effort is required for operation and maintenance, with only an average of 0.4 working hours per week. Therefore, house onsite grey water management systems are acceptable in rural communities, but attention should be given to the reasons of acceptance and barriers highlighted in this research. Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)
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Open AccessArticle
Mercury, Arsenic and Lead Removal by Air Gap Membrane Distillation: Experimental Study
Water 2020, 12(6), 1574; https://doi.org/10.3390/w12061574 - 31 May 2020
Cited by 4 | Viewed by 951
Abstract
Synthetic industrial wastewater samples containing mercury (Hg), arsenic (As), and lead (Pb) ions in various concentrations were prepared and treated by air gap membrane distillation (AGMD), a promising method for heavy metals removal. Three different membrane pore sizes (0.2, 0.45, and 1 μm) [...] Read more.
Synthetic industrial wastewater samples containing mercury (Hg), arsenic (As), and lead (Pb) ions in various concentrations were prepared and treated by air gap membrane distillation (AGMD), a promising method for heavy metals removal. Three different membrane pore sizes (0.2, 0.45, and 1 μm) which are commercially available (TF200, TF450, and TF1000) were tested to assess their effectiveness in combination with various heavy metal concentrations and operating parameters (flow rate 1–5 L/min, feed temperature 40–70 °C, and pH 2–11). The results indicated that a high removal efficiency of the heavy metals was achieved by AGMD. TF200 and TF450 showed excellent membrane removal efficiency, which was above 96% for heavy metal ions in a wide range of concentrations. In addition, there was no significant influence of the pH value on the metal removal efficiency. Energy consumption was monitored at different membrane pore sizes and was found to be almost independent of membrane pore size and metal type. Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)
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Open AccessArticle
Purification Effect of Sequential Constructed Wetland for the Polluted Water in Urban River
Water 2020, 12(4), 1054; https://doi.org/10.3390/w12041054 - 08 Apr 2020
Cited by 4 | Viewed by 933
Abstract
Constructed wetlands can play an active role in improving the water quality of urban rivers. In this study, a sequential series system of the floating-bed constructed wetland (FBCW), horizontal subsurface flow constructed wetland (HSFCW), and surface flow constructed wetland (SFCW) were constructed for [...] Read more.
Constructed wetlands can play an active role in improving the water quality of urban rivers. In this study, a sequential series system of the floating-bed constructed wetland (FBCW), horizontal subsurface flow constructed wetland (HSFCW), and surface flow constructed wetland (SFCW) were constructed for the urban river treatment in the cold regions of North China, which gave full play to the combined advantages. In the Yitong River, the designed capacity and the hydraulic loading of the system was 100 m3/d and 0.10 m3/m2d, respectively. The hydraulic retention time was approximately 72 h. The monitoring results, from April to October in 2016, showed the multiple wetland ecosystem could effectively remove chemical oxygen demand (COD), ammonia nitrogen (NH4+-N), total nitrogen (TN), total phosphate (TP), and suspended solids (SS) at average removal rates of 74.79%, 80.90%, 71.12%, 78.44%, and 91.90%, respectively. The removal rate of SS in floating-bed wetland was the largest among all the indicators (80.24%), which could prevent the block of sub-surface flow wetland effectively. The sub-surface flow wetland could remove the NH4-N, TN, and TP effectively, and the contribution rates were 79.20%, 64.64%, and 81.71%, respectively. The surface flow wetland could further purify the TN and the removal rate of TN could reach 23%. The total investment of this ecological engineering was $12,000. The construction cost and the operation cost were $120 and $0.02 per ton of polluted water, which was about 1/3 to 1/5 and 1/6 to 1/3 of the conventional sewage treatment, respectively. The results of this study provide a technical demonstration of the restoration of polluted water in urban rivers in northern China. Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)
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Open AccessArticle
The Effect of Submergence and Eutrophication on the Trait’s Performance of Wedelia Trilobata over Its Congener Native Wedelia Chinensis
Water 2020, 12(4), 934; https://doi.org/10.3390/w12040934 - 26 Mar 2020
Cited by 5 | Viewed by 765
Abstract
Climate change and artificial disturbance may lead to increased submergence and eutrophication near a riparian zone and the shift of terrestrial plants into a riparian zone. In this study, the responses of terrestrial invasive Wedelia trilobata (WT) and congener native Wedelia chinensis (WC) [...] Read more.
Climate change and artificial disturbance may lead to increased submergence and eutrophication near a riparian zone and the shift of terrestrial plants into a riparian zone. In this study, the responses of terrestrial invasive Wedelia trilobata (WT) and congener native Wedelia chinensis (WC) plants were examined under submergence and eutrophication. A greenhouse experiment was conducted in which ramets of WT and WC were investigated under two levels of submergence (S1 and S2) and three levels of nutrients (N1, N2 and N3) along with two cultures (mono and mixed). Submergence (S) did not affect the morphological traits of both the species but nutrients (N), culture (C) and their interaction, along with submergence, had a significant effect on the morphological traits of both the species. The growth of WC under high submergence and high nutrients was decreased compared with low nutrients (N1, N2) but WT maintained its growth in monoculture. In mixed culture, low submergence (S1) and low nutrients (N1, N2) made WC more dominant but high submergence (S2) and high nutrients (N3) made WT more successful than WC due to its high phenotypic plasticity and negative effect of competition intensity. It was concluded that both species survive and grow well under submergence and eutrophication, but high submergence and eutrophication provide better conditions for WT to grow well. Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)
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Open AccessFeature PaperArticle
Optimization and Analysis of Zeolite Augmented Electrocoagulation Process in the Reduction of High-Strength Ammonia in Saline Landfill Leachate
Water 2020, 12(1), 247; https://doi.org/10.3390/w12010247 - 16 Jan 2020
Cited by 4 | Viewed by 880
Abstract
This work examined the behavior of a novel zeolite augmented on the electrocoagulation process (ZAEP) using an aluminum electrode in the removal of high-strength concentration ammonia (3471 mg/L) from landfill leachate which was saline (15.36 ppt) in nature. For this, a response surfaces [...] Read more.
This work examined the behavior of a novel zeolite augmented on the electrocoagulation process (ZAEP) using an aluminum electrode in the removal of high-strength concentration ammonia (3471 mg/L) from landfill leachate which was saline (15.36 ppt) in nature. For this, a response surfaces methodology (RSM) through central composite designs (CCD) was used to optimize the capability of the treatment process. Design-Expert software (version 11.0.3) was used to evaluate the influences of significant variables such as zeolite dosage (100–120 g), current density (540–660 A/m2), electrolysis duration (55–65 min), and initial pH (8–10) as well as the percentage removal of ammonia. It is noted that the maximum reduction of ammonia was up to 71%, which estimated the optimum working conditions for the treatment process as follows: zeolite dosage of 105 g/L, the current density of 600 A/m2, electrolysis duration of 60 min, and pH 8.20. Furthermore, the regression model indicated a strong relationship between the predicted values and the actual experimental results with a high R2 of 0.9871. These results provide evidence of the ability of the ZAEP treatment as a viable alternative in removing high-strength landfill leachate of adequate salinity without the use of any supporting electrolyte. Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)
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Open AccessArticle
Development of a Combined Aerobic–Anoxic and Methane Oxidation Bioreactor System Using Mixed Methanotrophs and Biogas for Wastewater Denitrification
Water 2019, 11(7), 1377; https://doi.org/10.3390/w11071377 - 04 Jul 2019
Cited by 9 | Viewed by 1363
Abstract
We developed a lab-scale aerobic–methane oxidation bioreactor (MOB)–anoxic system, combining a MOB and the aerobic–anoxic denitrification process, and evaluated its potential for advanced nitrogen treatment in wastewater treatment plants (WWTPs). The MOB used biogas generated from a WWTP and secondary-treated wastewater to support [...] Read more.
We developed a lab-scale aerobic–methane oxidation bioreactor (MOB)–anoxic system, combining a MOB and the aerobic–anoxic denitrification process, and evaluated its potential for advanced nitrogen treatment in wastewater treatment plants (WWTPs). The MOB used biogas generated from a WWTP and secondary-treated wastewater to support mixed methanotroph cultures, which mediated the simultaneous direct denitrification by methanotrophs and methanol production necessary for denitrifying bacteria in the anoxic chamber for denitrification. Compared to the aerobic–anoxic process, the aerobic–MOB–anoxic system with an influent concentration of 4.8 L·day−1 showed a marked increase in the reduction efficiency for total nitrogen (41.9% vs. 85.9%) and PO4−3-P (41.1% vs. 69.5%). However, the integrated actions of high nitrogen and phosphorus consumption are required for methanotroph growth, as well as the production and supply of methanol as a carbon source for denitrification and methane monooxygenase-mediated oxidation of NH3 into N2O by methanotrophs. After three months of continuous operation using actual wastewater, the total nitrogen removal rate was 76.3%, equivalent to the rate observed in a tertiary-advanced WWTP, while the total phosphorus removal rate reached 83.7%. Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)
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Open AccessArticle
Cross-Linked Magnetic Chitosan/Activated Biochar for Removal of Emerging Micropollutants from Water: Optimization by the Artificial Neural Network
Water 2019, 11(3), 551; https://doi.org/10.3390/w11030551 - 17 Mar 2019
Cited by 25 | Viewed by 2190
Abstract
One of the most important types of emerging micropollutants is the pharmaceutical micropollutant. Pharmaceutical micropollutants are usually identified in several environmental compartments, so the removal of pharmaceutical micropollutants is a global concern. This study aimed to remove diclofenac (DCF), ibuprofen (IBP), and naproxen [...] Read more.
One of the most important types of emerging micropollutants is the pharmaceutical micropollutant. Pharmaceutical micropollutants are usually identified in several environmental compartments, so the removal of pharmaceutical micropollutants is a global concern. This study aimed to remove diclofenac (DCF), ibuprofen (IBP), and naproxen (NPX) from the aqueous solution via cross-linked magnetic chitosan/activated biochar (CMCAB). Two independent factors—pH (4–8) and a concentration of emerging micropollutants (0.5–3 mg/L)—were monitored in this study. Adsorbent dosage (g/L) and adsorption time (h) were fixed at 1.6 and 1.5, respectively, based on the results of preliminary experiments. At a pH of 6.0 and an initial micropollutant (MP) concentration of 2.5 mg/L, 2.41 mg/L (96.4%) of DCF, 2.47 mg/L (98.8%) of IBP, and 2.38 mg/L (95.2%) of NPX were removed. Optimization was done by an artificial neural network (ANN), which proved to be reasonable at optimizing emerging micropollutant elimination by CMCAB as indicated by the high R2 values and reasonable mean square errors (MSE). Adsorption isotherm studies indicated that both Langmuir and Freundlich isotherms were able to explain micropollutant adsorption by CMCAB. Finally, desorption tests proved that cross-linked magnetic chitosan/activated biochar might be employed for at least eight adsorption-desorption cycles. Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)
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Open AccessArticle
Inactivation and Loss of Infectivity of Enterovirus 70 by Solar Irradiation
Water 2019, 11(1), 64; https://doi.org/10.3390/w11010064 - 02 Jan 2019
Cited by 2 | Viewed by 1653
Abstract
Enterovirus 70 (EV70) is an emerging viral pathogen that remains viable in final treated effluent. Solar irradiation is, therefore, explored as a low-cost natural disinfection strategy to mitigate potential concerns. EV70 was exposed to simulated sunlight for 24 h at a fluence rate [...] Read more.
Enterovirus 70 (EV70) is an emerging viral pathogen that remains viable in final treated effluent. Solar irradiation is, therefore, explored as a low-cost natural disinfection strategy to mitigate potential concerns. EV70 was exposed to simulated sunlight for 24 h at a fluence rate of 28.67 J/cm2/h in three different water matrices, namely, phosphate-buffered saline (PBS), treated wastewater effluent, and chlorinated effluent. In the presence of sunlight, EV70 decreased in infectivity by 1.7 log, 1.0 log, and 1.3 log in PBS, effluent, and chlorinated effluent, respectively. Irradiated EV70 was further introduced to host cell lines and was unable to infect the cell lines. In contrast, EV70 in dark microcosms replicated to titers 13.5, 3.3, and 4.2 times the initial inoculum. The reduction in EV70 infectivity was accompanied by a reduction in viral binding capacity to Vero cells. In addition, genome sequencing analysis revealed five nonsynonymous nucleotide substitutions in irradiated viruses after 10 days of infection in Vero cells, resulting in amino acid substitutions: Lys14Glu in the VP4 protein, Ala201Val in VP2, Gly71Ser in VP3, Glu50Gln in VP1, and Ile47Leu in 3Cpro. Overall, solar irradiation resulted in EV70 inactivation and an inhibition of viral activity in all parameters studied. Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)
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Open AccessArticle
Potential Use of Dimocarpus longan Seeds as a Flocculant in Landfill Leachate Treatment
Water 2018, 10(11), 1672; https://doi.org/10.3390/w10111672 - 16 Nov 2018
Cited by 18 | Viewed by 1420
Abstract
Landfill leachate is a highly polluted and generated from water infiltration through solid waste produced domestically and industrially. In this study, a coagulation–flocculation process using a combination of Polyaluminium chloride (PACl) as a coagulant and Dimocarpus longan seed powder (LSP) as coagulant aid [...] Read more.
Landfill leachate is a highly polluted and generated from water infiltration through solid waste produced domestically and industrially. In this study, a coagulation–flocculation process using a combination of Polyaluminium chloride (PACl) as a coagulant and Dimocarpus longan seed powder (LSP) as coagulant aid was used in treating landfill leachate. LSP has been tested as the main coagulant and as coagulant aid with PACl. As the main coagulant, the optimum dosage and pH for PACl were 5 g/L and 6, respectively, with removal efficiencies of 67.44%, 99.47%, and 98% for COD, SS, and color, respectively. For LSP as the main coagulant, results show that LSP is not effective where the removal efficiencies obtained for COD, SS, and color were 39.40%, 22.20%, and 28.30%, respectively, with the optimum dosage of 2 g/L and pH 4. The maximum removal efficiencies of COD, SS, and color were 69.19%, 99.50%, and 98.80%, respectively, when LSP was used as coagulant aid with PACl. Results show that using LSP as coagulant aid was found to be more effective in the removal of COD, SS, and color with less PACl dosage. The PACl dosage was decreased from 5 to 2.75 g/L when LSP was used as a coagulant aid. Cost estimation for using PACl alone and using LSP as the coagulant aid showed a reduction in the cost of approximately 40% of the cost of using PACl alone. Overall, this study confirmed the efficiency of LSP to be used as a natural coagulant aid in leachate treatment. Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)
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Review

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Open AccessReview
The Application of Modified Natural Polymers in Toxicant Dye Compounds Wastewater: A Review
Water 2020, 12(7), 2032; https://doi.org/10.3390/w12072032 - 17 Jul 2020
Cited by 5 | Viewed by 933
Abstract
The utilization of various types of natural and modified polymers for removing toxicant dyes in wastewater generated by the dye industry is reviewed in this article. Dye wastewater contains large amounts of metals, surfactants, and organic matter, which have adverse effects on human [...] Read more.
The utilization of various types of natural and modified polymers for removing toxicant dyes in wastewater generated by the dye industry is reviewed in this article. Dye wastewater contains large amounts of metals, surfactants, and organic matter, which have adverse effects on human health, potentially causing skin diseases and respiratory problems. The removal of dyes from wastewaters through chemical and physical processes has been addressed by many researchers. Currently, the use of natural and modified polymers for the removal of dyes from wastewater is becoming more common. Although modified polymers are preferred for the removal of dyes, due to their biodegradability and non-toxic nature, large amounts of polymers are required, resulting in higher costs. Surface-modified polymers are more effective for the removal of dyes from the wastewater. A survey of 80 recently published papers demonstrates that modified polymers have outstanding dye removal capabilities, and thus have a high applicability in industrial wastewater treatment. Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)
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Open AccessReview
Metallic Iron for Environmental Remediation: Starting an Overdue Progress in Knowledge
Water 2020, 12(3), 641; https://doi.org/10.3390/w12030641 - 27 Feb 2020
Cited by 11 | Viewed by 1080
Abstract
A critical survey of the abundant literature on environmental remediation and water treatment using metallic iron (Fe0) as reactive agent raises two major concerns: (i) the peculiar properties of the used materials are not properly considered and characterized, and, (ii) the [...] Read more.
A critical survey of the abundant literature on environmental remediation and water treatment using metallic iron (Fe0) as reactive agent raises two major concerns: (i) the peculiar properties of the used materials are not properly considered and characterized, and, (ii) the literature review in individual publications is very selective, thereby excluding some fundamental principles. Fe0 specimens for water treatment are typically small in size. Before the advent of this technology and its application for environmental remediation, such small Fe0 particles have never been allowed to freely corrode for the long-term spanning several years. As concerning the selective literature review, the root cause is that Fe0 was considered as a (strong) reducing agent under environmental conditions. Subsequent interpretation of research results was mainly directed at supporting this mistaken view. The net result is that, within three decades, the Fe0 research community has developed itself to a sort of modern knowledge system. This communication is a further attempt to bring Fe0 research back to the highway of mainstream corrosion science, where the fundamentals of Fe0 technology are rooted. The inherent errors of selected approaches, currently considered as countermeasures to address the inherent limitations of the Fe0 technology are demonstrated. The misuse of the terms “reactivity”, and “efficiency”, and adsorption kinetics and isotherm models for Fe0 systems is also elucidated. The immense importance of Fe0/H2O systems in solving the long-lasting issue of universal safe drinking water provision and wastewater treatment calls for a science-based system design. Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)
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Open AccessFeature PaperReview
Application of Ionizing Radiation in Wastewater Treatment: An Overview
Water 2020, 12(1), 19; https://doi.org/10.3390/w12010019 - 19 Dec 2019
Cited by 5 | Viewed by 1284
Abstract
Technological applications of nuclear science and technology in different sectors have proved their reliabilities and sustainability over decades. These applications have supported various human civilization needs, ranging from power generation to industrial, medical, and environmental applications. Environmental applications of radiation sources are used [...] Read more.
Technological applications of nuclear science and technology in different sectors have proved their reliabilities and sustainability over decades. These applications have supported various human civilization needs, ranging from power generation to industrial, medical, and environmental applications. Environmental applications of radiation sources are used to support decision making processes in many fields; including the detection and analysis of pollutant transport, water resources management, and treatment of municipal and industrial wastewaters. This work reviewed recent advances in the research and applications of ionizing radiation in treating different wastewater effluents. The main objective of the work is to highlight the role of ionizing radiation technology in the treatment of complex wastewater effluents generated from various human activities and to address its sustainability. Results of both laboratory and industrial scale applications of this treatment technology have been reviewed, and information on operational safety of industrial irradiators, which affect the sustainability of this technology, has been summarized. Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment)
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