Wastewater Reuse Research Articles

Novel collector design and optimized photo-fenton model for sustainable industry textile wastewater treatment

Textile industry wastewater containing toxic dyes and high COD poses environmental hazards and requires treatment before discharge. This study addresses the challenge of treating complex textile wastewater using a novel integrated system. The system combines sedimentation, screening, adsorption, and an optimized solar photo-Fenton process to provide a sustainable treatment solution. A novel parabolic collector with a larger absorber tube diameter enhances solar radiation utilization at lower catalyst concentrations. This design is versatile, treating all types of wastewaters, especially those that contain colors, smells, solid and suspended materials, in addition to its importance for the treatment of difficult substances that may be present in industrial and sewage wastewaters that are difficult to dispose of by traditional treatment methods. Multivariate experiments optimized key photo-Fenton parameters (pH, catalyst dose, etc.) achieving significant pollutant removal (85% COD, 82% TOC, complete color) under specific conditions (pH 3, 0.2 g/L Fe(II), 1 mL/L H2O2, 40 °C and 100 L/h flow rate after 60 min irradiation). Kinetic modeling revealed second-order reaction kinetics, and multivariate regression analysis led to the development of models predicting treatment efficiency based on process factors. The key scientific contributions are the integrated system design combining conventional and advanced oxidation technologies, novel collector configuration for efficient utilization of solar radiation, comprehensive process optimization through multivariate experiments, kinetic modeling and predictive modeling relating process factors to pollutant degradation. This provides an economical green solution for textile wastewater treatment and reuse along with useful design guidelines. The treatment methodology and modeling approach make valuable additions for sustainable management of textile industry wastewater.

Utilization of Flotation Wastewater for Separation of Chalcopyrite and Molybdenite by Selective Surface Passivation

In the flotation separation process of a Cu-Mo-W polymetallic ore, the wastewater from the scheelite cleaning flowsheet contains large numbers of residual flocculants and metal ions, and the separation of chalcopyrite and molybdenite requires a large number of environmentally harmful depressants. Therefore, it is necessary to find new methods to reduce the environmental and cost pressures of wastewater treatment and the use of depressants. In this work, the flotation wastewater from the scheelite cleaning flowsheet for the separation of chalcopyrite and molybdenite by selective surface passivation was investigated for the first time. Flotations of single minerals and artificially mixed minerals with or without immersion pretreatment in the presence and absence of aeration were performed. The results showed that pulp pH had no effect on the flotation of either mineral, and a molybdenite recovery of 93.22% with a chalcopyrite recovery of 10.77% was achieved under the conditions of 10 days of immersion pretreatment with aeration, 350 mg/L of kerosene, and 100 mg/L of MIBC. By combining the electrochemical cyclic voltammetry analysis and characterization by XRD and SEM, the selective surface passivation mechanism of chalcopyrite was discussed, which could be due to the coverage of the insoluble oxidation products, especially jarosite. This work has simultaneously achieved the depressant-free flotation separation of molybdenite and chalcopyrite and the reuse of scheelite flotation wastewater, which is of great significance for environmental protection and cost saving.

Assessment of Greywater Reuse in a University Building in a Hyper-Arid Region: Quantity, Quality, and Social Acceptance

Since Tacna is a hyper-arid region, greywater is a potential alternative water source. This study aimed to quantify and characterize greywater in a university building with 732 students, as well as assess their perception of greywater reuse. Water meters were used to calculate greywater quantity. To assess untreated greywater quality, physical–chemical and microbiological parameters were analyzed. Questionnaires were used to measure students’ acceptance regarding greywater reuse using a Likert scale. The greywater quantity recorded in this study was 426.85 L/d, which is less than reported in previous global research. The greywater quality showed relatively low values regarding physical–chemical parameters; however, microbial contamination was higher compared to international permissible limits for wastewater reuse. Furthermore, it was found that the generated greywater has little biodegradability (0.38). Students disclosed a lower acceptance of reusing untreated greywater compared to a 77.05% acceptance of reusing treated greywater for green areas. According to the greywater characterization, biological treatment will not be enough to ensure environmental protection and user health; thus, physical–chemical treatment will also be needed. The produced greywater quantities would generate a 12.67% water saving if used for toilet flushing. The greywater volume fulfills the whole demand for watering green areas or green roofs. Students would assent to the reuse of treated greywater.

Water scarcity in the Kingdom of Saudi Arabia.

Saudi Arabia (SA) is one of the world's arid, most water-scarce nations without permanent water resources. The purpose of this article is to provide a comprehensive overview of Saudi Arabia's water resources availability and reliability in terms of water supply, demand, and the major challenges that water faces. Saudi has an annual water supply of roughly 89.5 m3 per person as consumption is rising in parallel with the country's rapid population growth and development. SA produces the most desalinated seawater in the world, accounting for 22% of worldwide consumption. Due to changes in agricultural demand, Saudi Arabia's overall water needs in 2020 were 15.98 BCM. Apart from agricultural use, the food industry utilizes up to 80% of freshwater supplies, with only around 20% of rain recharging the aquifer, meaning that the region will still be water-stressed by 2025. In addition to wastewater reuse, water expenses should be split between private investors and the government, and water losses in cities should be collected and recycled. Water development projects must also be safeguarded and have long-term viability for the community's future and well-being. Despite previous conservation efforts (public awareness campaigns, television and other public media messages, drip irrigation, and so on), more work is required, including improving water resource infrastructure, implementing environmental use of friendly technologies, and increasing economic feasibility, social acceptability, and management in light of the Sustainable Development Goals (SDG).

Pollution Load Reduction from Domestic Wastewater with Electrocoagulation Process for Agricultural Reuse

Objectives: The present study is aimed to investigate electrocoagulation of domestic wastewater and assessment of pollutants removal efficiency for potential reuse in agriculture. Methods: The electrocoagulation treatment of domestic wastewater with Fe – Fe electrodes was performed under optimal conditions of pH (8.0), current density (0.6 mA/cm2), treatment time (45 minutes), and NaCl dose (2.8 g/L) in a slurry type of reactor. The primary clarified and biotreated domestic wastewaters were subjected to electrocoagulation with Direct Current (DC) as power source. Findings: There was observed higher pollutants removal efficiency from the biotreated wastewater as compared with the primary clarified wastewater after electrocoagulation. The treated wastewaters showed significant removal of pollutants in terms of BOD (79.5% – 87.9%), COD (86.8% – 89.5%), TDS (87.4% – 89.9%), TSS (66.7% – 75.3%), conductivity (77.8% – 78.4%), turbidity (74% – 81.2%), colour (77.7% – 86.2%), nitrates (44.1% – 51.7%), and phosphates (48.7% – 55.9%) after electrocoagulation treatment. Electrocoagulation considerably improved the biodegradability index of the primary clarified (0.59 to 0.92) and biotreated (0.69 to 0.8) wastewaters. This indicates easy removal of the pollutants further by biological processes in the aquatic ecosystems. Electrocoagulation demonstrated potential for removal of pollution from the domestic wastewater for productive reuse in agriculture and urban areas. Novelty: There exist few studies of use of electrochemical process for treatment and reuse of domestic wastewater. The treated waters complied with the regulatory standards and had satisfactory quality for reuse in agriculture and urban activities. Keywords: Electrocoagulation, Domestic wastewater, Biodegradability index, Agricultural reuse, National Green Tribunal

Treatment and reuse of water: Economic Feasibility and assessment of Water Pricing Policies in Ouardanine irrigation district (Tunisia)

Treated wastewater reuse is a valuable water source in water scarcity conditions. If its technical feasibility is largely demonstrated, less attention is paid to the economic assessment. By applying an ex-post Cost-Benefit Analysis to Ouardanine irrigation district, in eastern Tunisia, the economic feasibility of wastewater treatment and reuse in irrigation was assessed. Data on costs and benefits were evaluated throughout the lifespan of the project and four scenarios - no treatment, treatment, treatment with reuse, and treatment with reuse without considering the environmental benefits - were considered. The results prove that: the project is economically profitable for all scenarios except the first; it is still profitable with an increase in costs or a decrease of benefits up to 30%; farmers are the main beneficiaries of the project which is financially not viable for both the treatment plant company and the public body charged of the distribution of water; the affordability of the treated wastewater price depends on the cropping pattern: with increased water pricing peach growers will still have substantial benefit while olive growers will reduce significantly their benefits.

All-Wood-Based Ionic Power Generator with Dual Functions for Alkaline Wastewater Reuse and Energy Harvesting.

Water-induced electricity harvesting has gained much significance for energy sustainability. Bio-based hydrovoltaic materials increase the attractiveness of this strategy. Although promising, it faces a challenge due to its reliance on fresh water and its inherently low power output. Herein, the energy from alkalinity-gradient power generation demonstrated the feasibility of reuse of alkaline wastewater to develop an all-wood-based water-induced electric generator (WEG) based on ion concentration gradients. The intermittent water droplets bring about uneven distribution of electrolyte and endow delignified wood with the difference of ion concentration along aligned cellulose nanochannels, thus supplying electrical power. The practice of using alkali reservoirs, including industrial wastewater, further contributes to electricity generation. The cubic WEG with a side length of 2 cm can produce an ultrahigh open-circuit voltage of about 1.1 V and a short-circuit current of up to 320 μA. A power output of 6.75 μW cm-2 is correspondingly realized. Series-connected WEGs can be used as an energy source for commercial electronics and self-powered systems. Our design provides a double value proposition, allowing for sustainable energy generation and wastewater reuse.

Screening and performance optimization of fungi for heavy metal adsorption in electrolytes.

The resource recovery and reuse of precious metal-laden wastewater is widely recognized as crucial for sustainable development. Superalloy electrolytes, produced through the electrolysis of superalloy scrap, contain significant quantities of precious metal ions, thereby possessing substantial potential for recovery value. This study first explores the feasibility of utilizing fungi to treat Superalloy electrolytes. Five fungi resistant to high concentrations of heavy metals in electrolytes (mainly containing Co, Cr, Mo, Re, and Ni) were screened from the soil of a mining area to evaluate their adsorption characteristics. All five fungi were identified by ITS sequencing, and among them, Paecilomyces lilacinus showed the best adsorption performance for the five heavy metals; therefore, we conducted further research on its adsorption characteristics. The best adsorption effect of Co, Cr, Mo, Re, and Ni was 37.09, 64.41, 47.87, 41.59, and 25.38%, respectively, under the conditions of pH 5, time 1 h, dosage 26.67 g/L, temperature 25-30°C, and an initial metal concentration that was diluted fivefold in the electrolyte. The biosorption of Co, Mo, Re, and Ni was better matched by the Langmuir model than by the Freundlich model, while Cr displayed the opposite pattern, showing that the adsorption process of P. lilacinus for the five heavy metals is not a single adsorption mechanism, but may involve a multi-step adsorption process. The kinetics study showed that the quasi-second-order model fitted better than the quasi-first-order model, indicating that chemical adsorption was the main adsorption process of the five heavy metals in P. lilacinus. Fourier transform infrared spectroscopy revealed that the relevant active groups, i.e., hydroxyl (-OH), amino (-NH2), amide (- CONH2), carbonyl (-C = O), carboxyl (-COOH), and phosphate (PO43-), participated in the adsorption process. This study emphasized the potential application of P. lilacinus in the treatment of industrial wastewater with extremely complex background values.

Separation of Chloride and Sulfate Ions from Desulfurization Wastewater Using Monovalent Anions Selective Electrodialysis.

The high concentration of chloride ions in desulphurization wastewater is the primary limiting factor for its reusability. Monovalent anion selective electrodialysis (S-ED) enables the selective removal of chloride ions, thereby facilitating the reuse of desulfurization wastewater. In this study, different concentrations of NaCl and Na2SO4 were used to simulate different softened desulfurization wastewater. The effects of current density and NaCl and Na2SO4 concentration on ion flux, permselectivity (PSO42-Cl-) and specific energy consumption were studied. The results show that Selemion ASA membrane exhibits excellent permselectivity for Cl- and SO42-, with a significantly lower flux observed for SO42- compared to Cl-. Current density exerts a significant influence on ion flux; as the current density increases, the flux of SO42- also increases but at a lower rate than that of Cl-, resulting in an increase in permselectivity. When the current density reaches 25 mA/cm2, the permselectivity reaches a maximum of 50.4. The increase in NaCl concentration leads to a decrease in the SO42- flux; however, the permselectivity is reduced due to the elevated Cl-/SO42- ratio. The SO42- flux increases with the increase in Na2SO4 concentration, while the permselectivity increases with the decrease in Cl-/SO42- ratio.

Improving water security and sanitation in rural areas: comparative evaluation of TiO2 and photo-Fenton processes for rural wastewater treatment and reuse

Improving water security and sanitation in rural areas: comparative evaluation of TiO2 and photo-Fenton processes for rural wastewater treatment and reuse

Filtration of Grey Water Using Herbs in a Columnar Evaluation

Filtration of Grey Water Using Herbs in a Columnar Evaluation

The Effects of Wastewater Reuse on Smallmouth Bass (Micropterus dolomieu) Relative Abundance in the Shenandoah River Watershed, USA.

Municipal and industrial wastewater effluent is an important source of water for lotic systems, especially during periods of low flow. The accumulated wastewater effluent flows-expressed as a percentage of total streamflow (ACCWW%)-contain chemical mixtures that pose a risk to aquatic life; fish may be particularly vulnerable when chronically exposed. Although there has been considerable focus on individual-level effects of exposure to chemical mixtures found in wastewater effluent, scaling up to population-level effects remains a challenging component needed to better understand the potential consequences of exposure in wild populations. This may be particularly important under a changing climate in which wastewater reuse could be essential to maintain river flows. We evaluated the effects of chronic exposure to wastewater effluent, as measured by ACCWW%, on the relative abundance of young-of-year (YOY), juvenile, and adult smallmouth bass (Micropterus dolomieu) populations in the Shenandoah River Watershed (USA). We found that increases in ACCWW% in the previous year and during the prespawn period were negatively correlated with the relative abundance of YOY, resulting in an average 41% predicted decrease in abundance (range = 0.5%-94% predicted decrease in abundance). This lagged effect suggests that adult fish reproductive performance may be compromised by chemical exposure during periods of high ACCWW%. No relationships between ACCWW% and juvenile or adult relative abundance were found, suggesting that negative effects of ACCWW% on YOY abundance may be offset due to compensatory mechanisms following higher ACCWW% exposure. Understanding the effects of wastewater effluent exposure at multiple levels of biological organization will help in the development of management strategies aimed at protecting aquatic life. Environ Toxicol Chem 2024;43:1138-1148. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

MBR and GAC filtration followed by UV disinfection – implications for wastewater reuse at full scale

ABSTRACT Influences of upstream wastewater treatment on the process combination of granular activated carbon (GAC) and ultraviolet (UV) disinfection were studied and the implications of this for wastewater reuse were assessed. GAC is an efficient chemical barrier but contributes little to the removal of indicator bacteria, and generally increases total bacteria concentrations, necessitating disinfection with UV radiation, for example, to ensure the safe reuse of wastewater. The efficiency of UV disinfection is impacted by factors such as particle concentration and UV absorbance of the water and is thus affected by upstream treatment processes. A full-scale wastewater treatment plant with a membrane bioreactor (MBR) followed by GAC filtration was compared to a treatment plant with a conventional activated sludge process and sand filtration, followed by GAC filtration. The removal of indicator bacteria was higher by the GAC filter that was preceded by an MBR. A UV fluence of 400 J/m2 was sufficient to reach irrigation water quality for both process combinations and to meet the criteria for microbial drinking water quality in the MBR + GAC effluent. One sample was selected for chemical analysis, comprising approximately 100 parameters, demonstrating that the MBR + GAC + UV (400 J/m2) effluent met all drinking water criteria except for nitrate levels.

Exploring the social metabolism of urban wastewater reuse: Analysis framework and a case study in South-Central Chile

Although wastewater reuse is a vital strategy for mitigating water scarcity, its implementation is complex and faces several challenges. To effectively inform decision-makers, comprehensive evaluations are essential, considering the strategy's benefits and socio-ecological constraints in a case-specific manner. This study employs the social metabolism concept to assess the sustainability of wastewater reuse, through the joint application of the Material Flow Analysis (MFA) and Multiscale Integrated Assessment of Societal and Ecological Metabolism (MuSIASEM) tools. We analyze key aspects of wastewater reuse, including its potential as a water source, its technical challenges, and main social constraints.The results of our analysis highlight the potential of wastewater reuse to improve urban self-sufficiency, replace water in relevant economic activities at the regional level, and avoid the environmental impacts of wastewater discharge. Nevertheless, the viability of wastewater reuse is constrained by variations in wastewater flow and effluent quality. This limitation is further compounded by social barriers, which become more pronounced with increased contact with reclaimed water. Overall, the proposed framework serves as a valuable tool for evaluating wastewater reuse alternatives. It can be enriched by in-depth assessments of critical problems, providing a comprehensive approach to address the multifaceted aspects of sustainable wastewater reuse.

Efficient removal of E. coli from wastewater by novel phytofabricated nano-zinc using antibacterial potential, kinetic studies, and response surface methodology

The present investigation explores the antibacterial potential of novel ZnO-NPs synthesized from Acacia nilotica pods extract and immobilized onto sodium alginate beads to control bacterial pollution in wastewater. Phenolics and flavonoids were major phytoconstituents acting as capping, reducing, and stabilizing agents. UV–Vis analysis showed strong absorption band at 340 nm. XRD and TEM revealed hexagonal crystalline structure for zincite of average particles diameter 33.87 and 32.74 nm, respectively. FTIR demonstrated several bands with functional groups (O–H, C-H, C = O, C = C, and C–O–C) involved in ZnO-NPs synthesis. SEM images showed NPs surface completely colonized by E.coli, while EDX spectrum showed signals for zinc (52.94%) and oxygen (26.58%) confirming NPs purity. Adhesion capacity studies revealed ZnO-NPs potential (0.5 g) to remove E.coli after 120 min. Kinetic and isotherm studies indicated that pseudo-second-order model and Freundlich isotherm were best fit describing adhesion mechanism. Electrostatic attraction between negatively charged E.coli and positively charged ZnO-NPs was followed by generation of H2O2 leading to cell apoptosis. Adhesion optimization using Box–Behnken design under response surface methodology was 99.8% at disinfectant dose 30 g/L, contact time 6 h, and E.coli concentration 150 × 107 cfu/mL. For application, real wastewater was treated with removal 98.2%, 97.2%, and 96.5% for total coliform, fecal coliform, and E.coli, respectively, after 6 h. ZnO-NPs showed sustainable efficiency during four consecutive cycles of treatment. The study concluded the efficiency, eco-friendly and cost-effectiveness of phytofabricated ZnO-NPs as disinfectants for wastewater and recommended future studies on large scale for possible wastewater reuse in safe unrestricted irrigation.

Law and Policy Framework Governing Wastewater (Reuse) Management in India

Abstract Freshwater resources are becoming scarce and severely affected due to urbanization and industrial pollution. The per capita water supply to every Indian household is getting lesser than the recommended level. In this scenario, wastewater is considered as a new source of water supply for agriculture, industrial use, etc. Apart from the water laws, the government also adopted various policies and schemes to promote the reuse of treated wastewater for non-potable uses. However, the ineffective implementation of water laws and wastewater policies brought a new set of challenges. It is in this connection this paper analyses the comprehensive overview of constitutional provisions, key provisions of relevant laws, policies, rules, regulations, judicial intervention on wastewater management, and reuse in India. It also identifies implementation challenges in the enforcement of wastewater laws and byelaws in India.

A holistic approach for performance evaluation of wastewater treatment plants: integrating grey water footprint and life cycle impact assessment.

Wastewater treatment plants (WWTPs) have positive and negative impacts on the environment. Therefore, life cycle impact assessment (LCIA) can provide a more holistic framework for performance evaluation than the conventional approach. This study added water footprint (WF) to LCIA and defined ϕ index for accounting for the damage ratio of carbon footprint (CF) to WF. The application of these innovations was verified by comparing the performance of 26 WWTPs. These facilities are located in four different climates in Iran, serve between 1,900 and 980,000 people, and have treatment units like activated sludge, aerated lagoon, and stabilization pond. Here, grey water footprint (GWF) calculated the ecological impacts through typical pollutants. Blue water footprint (BWF) included the productive impacts of wastewater reuse, and CF estimated CO2 emissions from WWTPs. Results showed that GWF was the leading factor. ϕ was 4-7.5% and the average WF of WWTPs was 0.6 m3/ca, which reduced 84%, to 0.1 m³/ca, through wastewater reuse. Here, wastewater treatment and reuse in larger WWTPs, particularly with activated sludge had lower cumulative impacts. Since this method takes more items than the conventional approach, it is recommended for integrated evaluation of WWTPs, mainly in areas where the water-energy nexus is a paradigm for sustainable development.

A story of hope and frustration: a wastewater-based agricultural frontier in the Algerian Sahara

ABSTRACT This study explores how wastewater reshapes the dynamics of agricultural settlement in the Algerian Sahara. It also discusses farmers’ hopes and frustrations around these dynamics. The study was carried out around the Berriane wastewater treatment facility. It is based on interviews with officials and farmers, a review of technical studies and direct field observations. We show how wastewater reuse regenerates traditional practices, such as the use of human waste as fertilizer and raw sewage to irrigate palm groves. We also discuss the problems that arise when the treatment plant is not managed properly, and the political ambivalence of State authorities regarding wastewater reuse.

Phosphorus-supplemented seawater–wastewater cyclic system for microalgal cultivation: Production of high-lipid and high-protein algae

The reuse of wastewater after seawater cultivation is critically important. In this study, a phosphorus-supplemented seawater–wastewater cyclic system (PSSWCS) based on Chlorella pyrenoidosa SDEC-35 was developed. With the addition of phosphorus, the algal biomass and the ability to assimilate nitrogen and carbon were improved. At the nitrogen to phosphorus ratio of 20:1, the biomass productivity per mass of nitrogen reached 3.6 g g−1 (N) day−1 in the second cycle. After the third cycle the protein content reached 35.7% of dry mass, and the major metabolic substances in PSSWCS reached the highest content level of 89.5% (35.7% protein, 38.3% lipid, and 15.5% carbohydrate). After the fourth cycle the lipid content maintained at 40.1%. Furthermore, 100.0% recovery of wastewater in PSSWCS increased the nitrogen and carbon absorption to 15.0 and 396.8 g per tonne of seawater. This study achieved seawater–wastewater recycle and produced high-lipid and high-protein algae by phosphorus addition.

Recent advances of membrane-based hybrid membrane bioreactors for wastewater reclamation

Membrane bioreactor (MBR) is an advanced wastewater treatment technology, which has been established for more than 3 decades. In MBRs, membrane separation allows not only rejecting microorganisms/greater-sized molecules but decoupling hydraulic retention time (HRT) and solid retention time (SRT). Low-pressure driven, porous membranes have been widely used in MBRs, but their performances are mainly limited for wastewater reuse applications. Recently, many attempts have been made to combine desalination technologies to advance hybrid MBR processes for wastewater reclamation. Nanofiltration (NF) and reverse osmosis (RO) have been applied with the MBRs to improve effluent quality, and their advantages and challenges have been well reported in terms of rejection efficiency, operational energy, fouling control and recovery of retentate stream. Alternatively, the direct introduction of non-pressurized desalination technologies such as forward osmosis (FO) and membrane distillation (MD) into MBR processes for wastewater reclamation or probably for microbial activity have been considered substantially due to their low energy consumption and excellent rejection efficiency of solid materials. However, several technical limitations still need to be resolved to commercialize hybrid FO- or MD-MBR processes. This paper reviews recent advances of MBR technology integrated with desalination technologies for wastewater reclamation and suggests perspectives to optimize membrane-based hybrid MBR process.