Wastewater Reclamation Research Articles

Fouling behavior and cleaning strategies of ceramic ultrafiltration membranes for the treatment and reuse of laundry wastewater

One of the most promising strategies for maintaining stable water sources for on-site wastewater reuse is greywater reclamation, particularly laundry wastewater reclamation. This study proposes an efficient strategy for the pre-treatment of laundry wastewater, which reduces membrane fouling and improves flux recovery after membrane cleaning. The fouling behavior, organic retention, and flux recovery rates of ceramic ultrafiltration (UF) membranes were comprehensively investigated using synthetic laundry wastewater. Under identical applied pressure and temperature conditions, a fouling resistance that corresponded to the water permeate flux and normalized flux was explored. Total organic carbon (TOC) retention was also tested to investigate the feasibility of using ceramic UF membranes as an effective pre-treatment for laundry wastewater reclamation. Furthermore, four different cleaning strategies for the fouled ceramic membranes were systematically compared, including deionized (DI) water, alkaline, acidic, and combined alkaline and acidic chemical agents to provide an in-depth understanding of the potential recovery rates of the membranes relative to the initial state. The filtration and treatment performance of real laundry wastewater samples collected from a university student dormitory was compared with synthetic laundry wastewater. This work provided valuable information on fouling behavior and cleaning strategies that could advance ceramic UF membrane pre-treatment technology for sustainable laundry wastewater reuse. Despite the challenges associated with the organic fouling and the potential of incomplete flux recovery in engineered systems, our findings provide insights into fouling mechanisms and cleaning strategies that could enable the optimization of engineered wastewater reuse systems.

High-Efficacy Hierarchical Dy2O3/TiO2 Nanoflower toward Wastewater Reclamation: A Combined Photoelectrochemical and Photocatalytic Strategy.

Developing a sustainable photocatalyst is crucial to mitigate the foreseeable energy shortage and environmental pollution caused by the rapid advancement of global industry. We developed Dy2O3/TiO2 nanoflower (TNF) with a hierarchical nanoflower structure and a near-ideal anatase crystallite morphology to degrade aqueous rhodamine B solution under simulated solar light irradiation. The prepared photocatalyst was well-characterized using powder X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, energy-dispersive spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller, diffuse reflectance UV-vis spectra, and X-ray photoelectron spectroscopy. Further analysis was performed to highlight the photoelectrochemical activity of the prepared photocatalysts such as electrochemical impedance spectroscopy, linear sweep voltammetry, photocurrent response, and a Mott–Schottky study. The crystalline Dy2O3/TNF exhibits superb photocatalytic activity attributed to the improved charge transfer, reduced recombination rate of the electron–hole pairs, and a remarkable red-shift in light absorption.

Reduction and discharge of SARS-CoV-2 RNA in Chicago-area water reclamation plants.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA is commonly excreted in the feces and urine of infected individuals and is, therefore, detected in wastewaters where infection is present in the surrounding population. Water reclamation plants (WRPs) that treat these wastewaters commonly discharge treated effluents into the surrounding environment, yet little is known about the removal or persistence of SARS-CoV-2 RNA through wastewater treatment systems and potential for eventual release into the environment. We collected 361 24-hour composite influent and effluent samples from seven WRPs in the Greater Chicago Area in Illinois. Samples were collected over a period of 21 weeks for three large WRPs (with design max flows of 1.89-2.32 billion gallons per day and serving a combined population of 4.62 million people) and 11 weeks for four smaller WRPs (with design max flows of 96.3-186 million gallons per day and serving a combined population of >0.5 million people). A total of two of the larger WRPs implemented seasonal disinfection (using UV light or chlorination/dechlorination) for 8 weeks of this sampling period. SARS-CoV-2 RNA was quantified in the influent and effluent samples by reverse-transcription quantitative PCR (RT-qPCR) of the N1 and N2 targets of the nucleocapsid (N) gene. Although SARS-CoV-2 RNA was regularly detected in influent and effluent from all WRPs, viral RNA concentrations in the effluent samples were considerably lower, with mean effluent: influent gene copy concentration ratios ranging from 1:160 to 1:2.95 between WRPs. Samples collected while disinfection was active vs. inactive did not show any significant difference in the portion of RNA persisting through the treatment process (P >.05).

An integrated techno-economic analysis on wastewater reclamation in Hong Kong: A comprehensive cost – Benefit analysis with life cycle assessment

Wastewater reclamation and reuse projects have been gaining significant attention as ways to secure sustainable water resources while preventing environmental degradation. However, traditional cost-benefit analyses do not reflect the true net benefits of these processes as they do not consider all externalities, particularly due to the difficulties in monetizing environmental impacts, thereby leading to underutilization. In this study, we conducted a hybrid cost-benefit analysis with an integrated environmental externality approach to evaluate the true net benefit of wastewater treatment and reclamation with explicit and implicit costs and estimated benefits. Firstly, we developed a cost-benefit analysis model based on the Drainage Service Department's statistical data from the Shek Wu Hui plant in Hong Kong from 2014 to 2018. Next, we estimated the external environmental benefits from pollutant abatement based on the shadow price of each pollutant by adopting a distance frontier function. We then conducted a life-cycle assessment to investigate the potential environmental impacts of the process using SimaPro 8.5.2.0 software and the EcoInvent 3 database, utilizing Stepwise2006 methodology for full monetization. A sensitivity analysis was applied to control for uncertainties as a robustness check. Our results show that aggregate cost, shadow price, and monetized environmental impact are estimated to be 4.47, 4.75, and 1.23 HKD per m3 of treated water respectively. Based on these results, our study illustrates that the true benefit is noticeably higher than the unit cost of wastewater reclamation, dependent upon a scale, and represents a breakeven point of 63,769 m3 of water reclamation per day. Our study further demonstrates that wastewater reclamation is viable from both social and economic perspectives and will increase the government budget by 81 million HKD. Therefore, this study can provide a basic guideline for developing a more complete economic valuation of wastewater treatment and reclamation projects.

Degradation impact of low pH mineral acids and long exposure period on the active layer of semi-aromatic polyamine-based nanofiltration membrane

Rapid degradation of the active layer of nanofiltration (NF) membranes by acids contained in water and wastewater during industrial processes, needs to be understood to develop acid-resistant membranes with prolonged stability and durability. This study focuses on the degradation impact of a typical semi-aromatic polyamine-based NF membrane excited by two mineral acids (HCl and H2SO4) having pH ≤ 0. Selected analytical tools were systematically engaged to investigate the morphological change, chemical composition, hydrophilicity and surface charge of the degraded membrane at varying and elongated exposure periods up to 150 days. The neat membrane was examined for comparison and the reaction mechanism between individual acid and the degraded membrane active layer was also studied. At early exposure periods of 7, 15 and 30 days, corresponding deterioration changes were noticed in both the HCl and H2SO4 degraded membranes. However, at extended exposure periods of 90 and 150 days, the impact of degradation was more severe on the H2SO4 degraded membrane as revealed by the SEM and XPS analyses. This was envisaged to be triggered by the prolonged dissociation of the acid which gradually weakens the bonds and the polymer structures, hence making it more vulnerable to further degradation. HCl and H2SO4 readily dissociate to form hydrogen ions; a condition that favors the acid-catalyzed hydrolysis reaction pathway of the degraded membranes. This study thus serves as a reference to the expected behavioral change of semi-aromatic polyamine-based NF membrane used in acidic wastewater treatment and reclamation for extended periods.

A new solar photo-Fenton strategy for wastewater reclamation based on simultaneous supply of H2O2 and NaOCl

This study presents, for the first time, the concurrent supply of the oxidants H2O2 and NaOCl in solar-driven Fenton-like processes at neutral pH with ferric nitrilotriacetate (Fe3+-NTA) for wastewater reclamation. Simultaneous Escherichia coli (E. coli) inactivation and the removal of the antibiotic sulfamethoxazole (SMX) at 50 μg/L in municipal effluents were investigated in 5-cm deep raceway pond reactors. First, the individual effects of reagent concentrations (1.47, 2.94 and 4.41 mM for H2O2; 0.134, 0.269 and 0.403 mM for NaOCl; 0.1 and 0.2 mM for Fe3+-NTA) on the economic efficiency (in terms of mass of SMX eliminated per Euro and per hour to attain complete E. coli inactivation and more than 50% of SMX removal) were considered. The highest economic efficiencies were 141 mgSMX/€·h with H2O2 and 222 with NaOCl, the reaction times being 105 and 60 min, respectively. Second, a new strategy for solar photo-Fenton with the combination of the most cost-effective conditions (1.47 mM H2O2 – 0.134 mM NaOCl – 0.1 mM Fe3+-NTA) was carried out in secondary effluents from two treatment plants with different technologies. Economic efficiency was substantially affected by wastewater composition, ranging from 178 to 1131 mgSMX/€·h with treatment times between 60 and 10 min, significantly improving the reported results for conventional solar photo-Fenton to date.

Intelligent Tools to Monitor, Control and Predict Wastewater Reclamation and Reuse.

Contemporary wastewater reclamation units entail several diverse treatment and extraction processes, with a multitude of monitored quality characteristics, controlled by a variety of key operational parameters directly affecting the efficiency of treatment. The conventional optimization of this highly complex system is time- and energy- consuming, frequently relying on intuitive decision making by operators, and does not predict or forecast efficiency changes and system maintenance. In this paper, we introduce intelligent solutions to enhance the operational control of the unit with minimal human intervention and to develop an AI-powered DSS that is installed atop the sensors of a water treatment module. The DSS uses an expert model, both to assess the quality of water and to offer suggestions based on current values and future trends. More specifically, the quality of the produced water was successfully visualized, assessed and rated, based on a set of input operational variables (pH, TOC for this case), while future values of monitored sensors were forecasted. Additionally, monitoring services of the DSS were able to identify unexpected events and to generate alerts in the case of observed violation of operational limits, as well as to implement changes (automatic responses) to operational parameters so as to reestablish normal operating conditions and to avoid such events in the future. Up to now, the DSS suggestion and forecasting services have proven to be adequately accurate. Though data are still being collected from early adopters, the solution is expected to provide a complete water treatment solution that can be adopted by a vast range of parties.

Photocatalytic membrane for in situ enhanced removal of semi-volatile organic compounds in membrane distillation under visible light

Membrane distillation (MD) is emerging as a promising technology for wastewater reclamation to relieve the shortage of freshwater. However, due to the contamination of semi-volatile organic compounds (s-VOCs), part of s-VOCs would transfer the membrane and impact the permeate quality during the MD process. Herein, an innovative AgCl/MIL-100(Fe)/PTFE photocatalytic membrane (AM/PTFE) was rationally synthesized in view of the increasing s-VOCs rejection. The AM/PTFE membrane was applied in the photocatalytic direct contact membrane distillation (DCMD) system and nitrobenzene (NB) was selected as the model contamination for evaluating removal performance of s-VOCs under visible light. Compared with the MD process, NB removal rate increased from 63.44% to 87.84% in the photocatalytic MD system. Moreover, stable performance was maintained over five NB removal cycles experiment with s-VOCs rejection higher than 84.84% in the end. The enhanced rejection of s-VOCs could be attributed to the combination of adsorption and photocatalytic. The volatile NB molecules were adsorbed on the surface of photocatalytic membranes, and the photo-electrons (e-) generated by immobilized nanomaterials could effectively remove pollutants under visible light irradiation. This photocatalytic MD system provides an attractive avenue for the water reclamation from s-VOCs contaminated wastewater in the practical applications.

Integrating Virus Monitoring Strategies for Safe Non-potable Water Reuse.

Wastewater reclamation and reuse have the potential to supplement water supplies, offering resiliency in times of drought and helping meet increased water demands associated with population growth. Non-potable water reuse represents the largest potential reuse market. Yet economic constraints for new water reuse infrastructure and safety concerns due to microbial water quality, and especially viral pathogen exposure, limit widespread implementation of water reuse. Cost-effective, real-time methods to measure or indicate viral quality of recycled water would do much to instill greater confidence in the practice. This manuscript discusses advancements in monitoring and modeling of viral health risks in the context of water reuse. First, we describe the current wastewater reclamation processes and treatment technologies with an emphasis on virus removal. Second, we review technologies for the measurement of viruses, both culture- and molecular-based, along with their advantages and disadvantages. We introduce promising viral surrogates and specific pathogenic viruses that can serve as indicators of viral risk for water reuse. We suggest metagenomic analyses for viral screening and flow cytometry for quantification of virus-like particles as new approaches to complement more traditional methods. Third, we describe modeling to assess health risks through quantitative microbial risk assessments (QMRAs), the most common strategy to couple data on virus concentrations with human exposure scenarios. We then explore the potential of artificial neural networks (ANNs) to incorporate suites of data from wastewater treatment processes, water quality parameters, and viral surrogates. We recommend ANNs as a means to utilize existing water quality data, alongside new complementary measures of viral quality, to achieve cost-effective strategies to assess risks associated with infectious human viruses in recycled water. Given the review, we conclude that technologies are ready for identifying and implementing viral surrogates for health risk reduction in the next decade. Incorporating modeling with monitoring data would likely result in more robust assessment of water reuse risk.

Feasibility Study of Water Reclamation Projects in Industrial Parks Incorporating Environmental Benefits: A Case Study in Chonburi, Thailand

Financial feasibility is usually a concern in water reclamation projects. Aside from internal benefits, water reclamation in industrial parks delivers health and environmental benefits not normally considered in cost–benefit analyses (CBA). This study investigated the influence of environmental benefits on the feasibility of water reclamation projects with flow rate scenarios in accordance with industrial parks in Chonburi, Thailand. CBAs of water reclamation plants for industrial water supply, consisting of ultrafiltration (UF) and reverse osmosis (RO), with flow rates of 5200, 10,000, 15,000, and 25,000 m3/day and discount rates of 3%, 5%, 7%, 9% and 11% were conducted. Considering only the direct costs and benefits, none of the projects were financially feasible. However, when the environmental benefits were included, the projects became profitable in all cases except those with a flow rate of 5200 m3/day and discount rates of 5%, 7%, 9%, and 11% and those with flow rates of 10,000 and 25,000 m3/day and an 11% discount rate. Further, CBAs of water reclamation projects in industrial parks for irrigation were conducted with post-treatment processes consisting of sand filtration and chlorine disinfection for flow rates of 240, 480, 2400, 3600, and 4800 m3/day. The projects are profitable, regardless of environmental benefits.

101 A CTS Team Approach to Wastewater-Based Epidemiology of Non-Typhoidal Salmonella in Gainesville, FL

OBJECTIVES/GOALS: The goal of this project is to apply wastewater-based epidemiology to determine the trends of NTS through analysis of influent wastewater, and to isolate and identify circulating serotypes among samples that are representative of the human population in Gainesville, FL. METHODS/STUDY POPULATION: This study is being conducted in Gainesville, FL, a suburban city in North Central Florida with approximately 133,997 residents served by two wastewater reclamation facilities (WRF). Fifty-three weekly influent composite wastewater samples were collected between September 2020 and September 2021 from each WRF. Wastewater samples were processed using an adsorption-based sample concentration method and invA genetic target for NTS DNA detection and quantification via qPCR. The quantified NTS DNA wastewater concentration from each WRF was summed to determine the overall concentration. Bacterial isolation was conducted on stored wastewater of qPCR positive samples using EPA method 1682. Recovered isolate serotypes were identified through whole-genome sequence analysis. RESULTS/ANTICIPATED RESULTS: Overall, NTS was positive in Gainesville wastewater in 48/53 weeks between September 2020 – September 2021. 83/106 (78%) samples tested positive for NTS from both WRFs. The mean wastewater concentration from each WRF was 3.53 (Main St.) and 3.31 Log10 invA Genetic Copies/L. The overall mean city concentration was 6.85 Log10 invA Genetic Copies/L. There were sustained periods of NTS in the wastewater during the months of December-February and May-August. There was no observed seasonal trend in NTS wastewater concentrations over the study period. Culture-based methods will provide a comprehensive review of circulating serotypes that are responsible for both clinical and subclinical infections within the community. DISCUSSION/SIGNIFICANCE: Florida has an incidence of NTS twice the national average. Clinical surveillance is the current standard for community surveillance of NTS. Only 28% of NTS cases are identified in a clinical setting, leaving a major gap in community surveillance. This project has helped fill this gap and provided a comprehensive community-level assessment of NTS.

Surface grafting with diverse charged chemical groups mitigates calcium phosphate scaling on reverse osmosis membranes during municipal wastewater desalination

Calcium phosphate scaling on reverse osmosis (RO) membranes during the desalination of municipal wastewater remains a major problem. This study modified RO membranes by graft polymerization using hydrophilic methacrylate monomers to reduce scaling and investigated the effects of surface charge and exposed functional groups on scaling during municipal wastewater desalination. Grafting was performed using negatively charged, neutral, positively charged, and mixed charge monomers. Testing the modified membranes during RO desalination of a solution simulating treated domestic wastewater effluents from the Shafdan wastewater reclamation plant in Israel revealed improved antiscaling performance by grafted membranes compared with the pristine (unmodified) membrane. In particular, membranes grafted using neutral and mixed charge monomers showed the best antiscaling tendencies: 25.6% and 27.6% decrease in flux, respectively, compared with a 59.1% decrease using the pristine membrane. These results, together with physico-chemical characterization, suggested that calcium phosphate precipitation and scaling on the grafted RO membranes are driven mainly by electrostatic and dipole–dipole interactions between charged chemical groups exposed on the membrane surface and ionic species in the test solution; these interactions are minimized in membranes grafted with neutral or mixed charge poly (methacrylate) groups, resulting in enhanced antiscaling performance. This study provides insight into the antiscaling mechanisms of hydrophilic poly (methacrylate) chains grafted on RO membranes, and thus can potentially aid efforts to mitigate calcium phosphate scaling during RO desalination of municipal wastewater. • Diverse charged monomers grafted on RO membrane to mitigate Ca 3 (PO 4 ) 2 scaling. •Grafted membranes exhibit enhanced performance in RO wastewater desalination. •Neutral and mixed-charge grafted polymers show lowest flux decline. •Electrostatic interactions of surface functional groups with ions dominate scaling.

Potassium ferrate combined with ultrafiltration for treating secondary effluent: Efficient removal of antibiotic resistance genes and membrane fouling alleviation

Antibiotic resistance genes (ARGs) are considered as emerging environmental contaminants, which should be controlled by wastewater treatment plants to prevent their discharge into the environment. However, conventional treatment techniques generally fail to successfully reduce ARGs, and the release of cell-free ARGs was underestimated. In this study, potassium ferrate (Fe(VI)) pretreatment combined with ultrafiltration (UF) process was developed to remove both cell-associated and cell-free ARGs in real secondary effluent, compared to ferric chloride (Fe(III)) and poly-aluminum chloride (PACl) pretreatment processes. It was found that total ARGs especially cell-free ARGs were effectively removed by Fe(VI) oxidation. However, due to the poor settleability of the negatively charged particles formed by Fe(VI) in the secondary effluent, the removal of cell-associated ARGs was less compared to Fe(III) and PACl pretreatments. The combination of Fe(VI) and UF removed the most ARGs (3.26 - 5.01 logs) due to the efficient removal of cell-free ARGs by Fe(VI) (> 2.15 logs) and co-interception of both cell-associated ARGs and Fe(VI) formed particles of the UF. High-throughput sequencing revealed that Fe(VI) decreased the viability and relative abundances of the potential ARGs hosts. Fe(VI)-UF exhibited the best performance on humic-like fluorescent organic matters removal, as well as the least phytotoxicity in the effluent. Moreover, membrane fouling was remarkably alleviated by Fe(VI) pretreatment because (1) Fe(VI) removed macromolecules such as protein-like and polysaccharide-like substances which would block the membrane pores, (2) Fe(VI) improved the hydrophilicity of foulants and reduced the hydrophobic adsorption between foulants and membrane. In short, Fe(VI)-UF is a promising technology to efficiently remove ARGs (especially cell-free ARGs) and alleviate UF membrane fouling in wastewater reclamation.

Unveiling the optimal ammonia-oxidising bacterial consortium for polishing low ammonia-contaminated wastewater

Ammonia-oxidising bacteria (AOB) consortium has attracted attention considering the cost savings in wastewater treatment. The study aims to optimise the composition of the AOB consortium for ammonia removal. AOB bacteria were isolated from the activated sludge of a coffee effluent bioreactor. All isolates were cultivated in a mineral salt medium containing carbon and ammonia sources in the screening test. The three effective isolates denoted as NS2, NB1 and PS were identified as Burkholderia latens (MW485434), Paenibacillus sp. (MW485433), and Providencia rettgeri (MW485435) respectively. The results showed that isolate NS2 (88.4%), NB1 (62.7%), and PS (63.3%) produced the highest ammonia removal among other isolates of their distinctive agar media. The composition of the AOB consortium (NS2, NB1, and PS) were optimised using Simplex Lattice Mixture Design. The optimised consortium ratio of these effective isolates achieved 85% and 78% of ammonia and COD removal efficiency respectively. This consortium has a great potential as a bioremediation agent for ammonia removal in wastewater reclamation.

Comparison of Pretreatment Methods for Salinity Gradient Power Generation Using Reverse Electrodialysis (RED) Systems.

With the increasing concern about climate change and the energy crisis, the use of reverse electrodialysis (RED) to utilize salinity gradient power (SGP) has drawn attention as one of the promising renewable energy sources. However, one of the critical issues in RED processes is membrane fouling and channel blockage, which lead to a decrease in the power density. Thus, this study aims to improve our understanding of SGP generation by using RED by investigating the effect of pretreatment on the RED performance. Experiments were conducted by using a laboratory-scale experimental setup for RED. The low-salinity and high-salinity feed solutions were brackish water reverse osmosis (BWRO) brine from a wastewater reclamation plant, and a NaCl solution simulating seawater desalination brine. Several pretreatments were applied to the RED process, such as cartridge filter (CF), microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), activated filter media (AFM), and granular activated carbon (GAC). The results indicate that the open-circuit voltage (OCV) and the power density were similar, except for in the NF pretreatment, which removed the dissolved ions to increase the net SGP. However, the pressure in the RED stack was significantly affected by the pretreatment types. The excitation–emission matrix (EEM) fluorescence spectroscopy and the parallel factor analysis (PARAFAC) quantified the organic compounds that are related to the stack pressure. These results suggest that the removal of both colloidal and organic matters by pretreatments is crucial for improving the RED performance by reducing the pressure that is increased in the RED stack.

Incorporating catalytic ceramic membrane into the integrated process of in situ ozonation, membrane filtration and biological degradation: Enhanced performance and underlying mechanisms

The integrated process comprising of in situ ozonation, ceramic membrane filtration and biologically active carbon filtration has a bright application prospect in wastewater reclamation to confront the global water crisis. Additionally, ceramic membranes of stronger catalytic activity are highly desirable so as to further increase the process cost-efficiency. In this study, a Mn-loaded catalytic membrane was tested by conducting pilot-scale experiments of the integrated process to measure its performance in enhancing pollutant removal and in alleviating membrane fouling. Lab-scale experiments were also conducted in order to investigate the underlying mechanisms in which the conventional Al2O3 membrane was used for comparison. Results showed that the integrated process with an incorporated catalytic membrane performed very well in that at a water flux as high as 80 L/m2/h and an ozone dosage of 5 mg/L, the treated water satisfied the guideline values for indirect potable reuse and membrane fouling was minimal. Reducing the ozone dosage to 4 mg/L can still achieve significant membrane fouling control effects, and maintain good effluent quality. Catalytic ozonation could lead to the generation of hydroxyl radicals, and the catalytic ozonation effect was much stronger when the catalytic membrane was used. Catalytic ozonation took place in both the membrane tank and membrane pores, with comparable contributions to the pollutant removal and membrane fouling control. Redundancy analysis (RDA) of membrane fouling characteristics showed that residual ozone concentration in membrane tank was an essential parameter and catalytic ozonation could be more effective in abating irreversible fouling than reversible fouling. RDA also confirmed that a lower ozone dosage would be sufficient for membrane fouling control when the catalytic membrane was used. This study evidently suggested the advantage of using catalytic ceramic membrane in the integrated process for efficient while economic treatment and reclamation of wastewater.

Biological phosphorus removal and its microbial community in a modified full-scale activated sludge system under dry and wet weather dynamics

Enhanced biological phosphorus removal (EBPR) performance and microbial community dynamics during dry and wet-weather conditions of a full-scale treatment plant was evaluated by converting a section of activated sludge basins using low-cost operational modifications into an anoxic/anaerobic zone to promote EBPR. Two trains of the activated sludge system at the Des Moines, Iowa Metropolitan Wastewater Reclamation Facility were used for the study with one train modified for EBPR, and the other remained as nitrification-only for comparison.In addition to measuring the modification effectiveness for phosphorus removal, performance was compared during dry and wet weather conditions over the course of two summer seasons to improve understanding of wet and dry weather dynamics for EBPR. DNA sequencing and qPCR tests were conducted to develop an understanding of microbial population changes between control and modified basins and wet and dry weather conditions.Basin hydraulic retention times varied from 2.6 to 12.7 hours with an average of 8.9 hours. EBPR activity was successfully established in the modified basins with average phosphorus content of the return activated sludge 0.032 ± 0.002 compared to 0.016 ± 0.001 mg TP/mg TSS (95% confidence) in the control basins. Phosphorus removal was significantly decreased by prolonged wet weather conditions, particularly in year two of the study, however the modified basin maximum removal of 96% and average of 43.7 ± 5.3% remained significantly higher than the maximum of 46% and average 12.6 ± 2.4% removal in the control basins.DNA sequencing showed a significant increase in relative abundance of phyla Chloroflexi, Nitrospirae, and Verrucomicrobia in the modified basins, but no correlation to EBPR performance. qPCR indicated significant increase in relative quantity of Accumulibacter, but not for Actinetobacter-like phosphorus accumulating organisms (PAOs), which includes the PAO Tetrasphaera. Significant abundance of some Accumulibacter clades found within the modified basins was contrary to previous literature which focused on small-scale and batch studies. A higher than expected dominance of clade I and increased relative quantities of clades IIB and IIC during extended wet weather was observed which may have contributed to rapid recovery of phosphorus removal when dry weather resumed. The abundance of PAOs did not significantly correlate with changes in phosphorous removal performance, contrary to reports from previous small-scale and batch studies.

Constructed Wetlands for Reclamation and Reuse of Wastewater and Urban Stormwater: A Review

In recent years, increasing attention has been given for reclamation and reuse of water (wastewater and stormwater) in the context of augmenting water supplies. Constructed wetland (CW) systems make use of natural substrates, plants, and microbes for decontamination of wastewater and stormwater. These nature-based water treatment systems are cost-effective and sustainable. This review critically analyzes the recent advances on the application of CW systems for removal of total suspended solids (TSS), various chemical (nutrients including total nitrogen and total phosphorus, heavy metals, and organics) and microbial pollutants (Escherichia coli, enterococci, fecal coliforms, etc.) in wastewater and stormwater. Furthermore, the influence of key factors including CW configurations, substrates, vegetation, ambient temperature/seasonal changes, oxygen levels and hydraulic retention time on the performance of CW systems are discussed. Insights into various pollutant removal mechanisms, microbial diversity and modeling (kinetics, hydrological and mechanistic) are provided. CW systems show good performance for removal of diverse pollutants from wastewater and stormwater. The pollutant removal mechanisms include physical (sedimentation and filtration), chemical (sorption, complexation and precipitation) and biological (biodegradation, microbial transformation and microbial/plant assimilation) processes. The dominant microbial communities enriched in CW systems include nitrifiers, denitrifiers and organic biodegraders. The key knowledge gaps in the development of multifunctional CW systems are highlighted. We believe that this critical review would help urban planners, environmental engineers and managers with implementation of innovative strategies for wastewater and stormwater reclamation and reuse to alleviate water stress in urban areas and to contribute to environmental sustainability. Moreover, this review would help to optimize the performance of CW systems as well as to develop regulatory guidelines for installation, operation and maintenance of CW systems.

The underlying mechanism insights into support polydopamine decoration toward ultrathin polyamide membranes for high-performance reverse osmosis

The development of ultrathin polyamide (PA) nanofilms with desirable water permeance and high selectivity has been recognized as crucial for energy-efficient desalination of salty water and wastewater reclamation. In this study, an ultrathin PA reverse osmosis membrane (∼25 nm) was fabricated via polydopamine (PDA) interlayer-mediated interfacial polymerization onto a polyethersulfone (PES) substrate. The ultrathin PDA interlayer was soldered in situ onto PES substrates by precisely controlling the ammonia-initiated self-assembly process. Furthermore, the PDA interlayer conferred a high-density uptake toward aqueous amine monomers and served as a quasi-molecular-scale regulator that mediated their diffusion into the organic phase to polymerize with the acyl chloride of 1, 3, 5-benzenetricarbonyl trichloride (TMC). The synergistic effects triggered self-sealing and inhibited membrane growth, promoting the formation of an ultrathin and defect-free PA nanofilm with a hierarchical nanostripe surface. The newly developed membranes exhibited a desirable water permeance of up to 1.44 L m−2 h−1·bar−1, almost triple that of the pristine PA membrane (0.44 L m−2 h−1·bar−1), and a simultaneously enhanced rejection ratio of 99.2% toward NaCl. This work sheds light on strategies to develop ultrathin PA-based membranes with high water permselectivity for environmental- and energy-relevant applications.

Wastewater reclamation design from sewerage system for gardening activity in Universitas Pertamina

Wastewater recycling is one of the criteria for continuous innovation at the campus level. Reclamation of water from the sewage system for gardening activities is one way to achieve this target at Universitas Pertamina. The aim of this study is to design and verify a water treatment unit from sewage to ready-to-use water for gardening activities. The units needed for the wastewater treatment system are a tank, Horizontal Roughing Filter (HRF), Rapid Sand Filtration (RSF), reservoir, and disinfection. The expected quality of effluent from processing is TDS 278 mg/L; TSS 1.3 mg/L; Turbidity 0.17 NTU; BOD5 0.63 mg/L; COD 6.12 mg/L; Total phosphate 0.95 mg/L; Nitrate 0.07 mg/L; detergent 0.7 mg/L; and total coliform MPN/100mL. The most important parameter in the sewerage water treatment process is the total coliform which must achieve an efficiency of 99%. This conventional method of water treatment is used because the availability of land is still sufficient, if it is not sufficient then further processing that is efficient, environmentally friendly, and has economic value is required.