Wastewater Reuse Research Articles

Ozonation in Wastewater Disinfection

Due to the potential microbiological hazard associated with discharging treated sewage into the receiving body, its disinfection is a key issue to protect ecological safety and human health. Water scarcity and drinking water supply, irrigation, rapid industrialization, use of treated water, protection of water sources, overpopulation and environmental protection force us to look for solutions to ensure safe reuse of wastewater, and this depends primarily on the quality of wastewater disinfection. Many wastewater disinfection methods are commonly used. One of the chemical processes of disinfection sludge is ozonation. Ozonation is widely used in wastewater treatment by oxidation, because ozone is a very strong and effective oxidizing agent. Studies have shown that the effectiveness of ozone in disinfecting water and sewage is up to 50% greater than that of chlorine . An additional advantage of this method is that it also eliminates odors that may be unavailable. The article presents the results of research on the effectiveness of ozonation treatment in the disinfection of treated sewage, based on indicator bacteria such as coliforms, including Escherichia coli, mesophiles, psychrophiles, and spores. The study took into account various effects of time (dose) and temperature. For the purpose of this study, both traditional and modern methods of assessing microbiological quality of wastewater were used. The first one is represented by conventional culture measurements and the second one by using a luminometer (ATP) and flow cytometer (FCM).

The efficient abatement of contaminants of emerging concern by LED-UV275nm/electrochemical chlorine for wastewater reuse: kinetics, degradation pathways, and cytotoxicity

Treating wastewater to augment surface water can be a practicable solution to water scarcity, while the residual contaminants of emerging concern (CECs) and inorganic ions put forward new requirements to the treatment methods. Electrochemical chlorine process (EC/Cl2) utilizes the remaining Cl− in wastewater to generate free chlorine and radicals, which could be further improved in conjunction with LED UV275nm irradiation (UV-EC/Cl2). Compared to UV only and EC/Cl2, UV-EC/Cl2 could effectively decompose the selected CECs at higher rates due to the much higher yield of reactive chlorine species (Cl•, ClO•, and Cl2•−). A MATLAB R2021a programming method was developed to estimate the order of magnitude of these radicals, and Cl2•− was the most abundant radical. In the UV-EC/Cl2 system, CECs with phenolic or aniline moieties were mainly degraded by electrochemical oxidation (EC), ClO•, and Cl2•−; and the CECs with weakly electron-donating moieties were predominately decomposed by EC, •OH, and Cl•. The degradation pathways of levofloxacin, diclofenac, carbamazepine (CBZ), and ibuprofen were proposed according to the transformation products (TPs) detected by LC/Q-TOF-MS. Moreover, the cytotoxicity of spiked CBZ in real water samples, that were discharged to surface water, was significantly reduced by UV-EC/Cl2. Interestingly, the electrical energy per order (EE/O) for CBZ decomposition by LED UV275nm-EC/Cl2 (1.46 kWh m−3 order−1) is lower than that by UV/Cl2, EC/Cl2, and UV254nm-EC/Cl2. The results indicate that UV-EC/Cl2 could be used as a promising method to remediate CECs during the tertiary treatment and reuse of wastewater for augmenting surface water.

Treatment of greywater using banana peel, corn cob and orange peel as major filter media- a review

Water isthe most important element required for the existence of all living beings on earth. As the population increases, water demand also increases. About 75-80% of water through distribution pipe reaches the sewer as waste water. So it is a need of mankind to recycle and reuse waste water. The domestic water (Grey Water from TIST campus) from household can be treated and can be used for irrigation rather than disposing into river. This paper focus on grey water filtration using Banana Peel, Orange Peel and Corn cob as a filter media. All are good natural absorbent which can remove excess nutrients suspended solids and can even remove pollutants and sediments from wastewater. Orange peel is a great biosorbent. The orange peels biosorbent is one of the best biosorbent for removal of ammonia and nitrate present in water. Banana peels are capable of adsorbing various metals and other pollutants present in industrial waste waters, provided the peels are pre-treated with proper surface-activeagents. Corn cobs have the efficiency to adsorb contaminants from grey water. The purpose of this paper is Treatment of Greywater using Banana Peel, Orange Peel and Corn cob as major filter media.

Fe3S4/persulfate-based pre-oxidation for mitigating membrane fouling and enhancing synergistic perfluorooctanoic acid removal: Influence of pH and persulfate types

Aerobic granular sludge membrane system (AGSMS) represents a new wastewater reuse treatment technology. However, the challenges of membrane fouling and limited micropollutant removal efficiency significantly impact its potential for further application. Consequently, this study aimed to address these concerns by employing Fe3S4/persulfate pretreatment to mitigate membrane fouling and enhance perfluorooctanoic acid (PFOA) removal in AGSMS. The effects of pH and persulfate types were investigated by assessing membrane flux, fouling resistance, membrane characterization, and effluent properties. Results showed that optimal mitigation of membrane fouling and removal of PFOA were achieved using Fe3S4-activated PMS at a pH of 6. The primary mechanism for Fe3S4-activated PMS involved the generation of SO4•− and 1O2. Moreover, the fouling mechanism transitioned from cake layer fouling and intermediate blocking fouling to complete blocking fouling in the presence of Fe3S4/PMS. The application of extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory revealed that at pH 6.0, there was a significant increase in the energy barrier for both foulant-membrane and foulant-foulant interactions, leading to an effective mitigation of membrane fouling. Correlation analysis demonstrated a significant influence of polysaccharides and total phosphorus concentration on mitigating membrane fouling. Furthermore, pH played a crucial role in mitigating membrane fouling as well as pollutant removal by influencing both coexisting ion states in solution and catalyst properties. This study offers valuable insights for future research and provides essential theoretical guidance for large-scale applications of AGSMS technology in wastewater treatment.

Integrating wastewater reuse into water management schemes of Caribbean SIDS: A Trinidad and Tobago case study

Abstract Integrating Wastewater Reuse (WWRU) into national Water Management Schemes (WMS) is crucial as Small Island Developing States (SIDS) attempt to cope with water resource constraints in a changing climate. In 2022, the Global Environment Facility Caribbean Regional Fund (GEF CReW+) on Wastewater Management, the Ministry of Public Utilities (MPU), Trinidad and Tobago and the Trinidad and Tobago Bureau of Standards (TTBS) spearheaded the development of a national voluntary standard for treated wastewater reuse focused on agricultural and landscaping uses. During the process, the MPU conducted a Knowledge, Attitudes and Practices (KAP) and Willingness to Pay (WTP) assessment to inform the standard and subsequent implementation. Results indicated `good' knowledge on wastewater and WWRU (59.3%), however attitudes and practices were considered `poor'. Inferential Statistics performed on numerically coded survey response data revealed no statistically significant relation with the demographic factors assessed; 84.1% of respondents were willing to use treated wastewater with health concerns identified as the main barrier; 27.3% of respondents were willing to pay the same price as conventional water, while 31.2% were willing to pay 25 -50% less. This assessment can inform the implementation and pricing process and provide valuable insights to increase the uptake of WWRU in the region.

Reuse of Wastewater and Hydrogeneration: Sustainable Land Division Project

Abstract The present case study - Sustainable Cerrado Subdivision Project in Arouca (Portugal) - proposes the implementation of a design solution that promotes ‘sustainable neighborhoods’, expanding the concept of ‘sustainable homes’. This type of project results from the application of established construction methodologies and innovative solutions, aiming to meet society’s needs with the least possible mobilization of resources (natural, energy, and financial), considering water and energy efficiency as central elements. More specifically, the goal is to reduce the inflows into public wastewater and stormwater drainage systems by changing the consumption habits of the population and collecting rainwater in impermeable areas, as well as treating greywater for non-potable reuse. In water supply systems, there is potential for energy production through microturbines that can harness the energy required for pressure control - hydrogeneration.

Performance and economic analysis of the cooling tower blowdown water treatment system in a coal-fired power plant

In recent years, the treatment and reuse of wastewater have been widely of interest due to the severe shortage of water resources. As is well known, a huge amount of water is consumed in coal-fired power plants, especially for the circulation cooling system in a cooling tower. Therefore, research on the circulating cooling system and cooling tower blowdown water (CTBD) treatment is crucial. In this study, a computational model was established to study the treatment of CTBD by reverse osmosis (RO) and direct contact membrane distillation (DCMD). Recycled fresh water was used as a water supply for the cooling tower. The effects of the main operating parameters on the performances of the RO and DCMD with/without waste heat utilization were explored. The water-saving effects, energy consumption amounts, and economics of the three systems were analyzed comparatively. The results showed that better water-saving performance of the DCMD with waste heat utilization was achieved with a water-saving rate of 18.4% and that the energy consumption and cost were slightly lower than those of the RO. The lowest water treatment cost of the DCMD with waste heat utilization was 3.38 Ұ/m3. In addition, the effect of electricity price on the costs was studied. When the electricity price was higher than 0.31 Ұ/kWh, the DCMD with waste heat utilization was more economical.

Domestic Water Conservation in the Federal Capital Territory of Nigeria: Perceptions and Practices

Many regions in Nigeria currently experience physical or economic water scarcity; a situation that isexpected to worsen because of the nation’s rapid population growth, which has resulted in increased pressure on available freshwater resources. This study, therefore, examines water conservation practices in the Federal Capital Territory (FCT), one of the fastest-growing areas in Nigeria. A questionnaire was administered to 649 respondents, from across the six Area Councils that make up the Territory. The findings revealed that water investments in the FCT have not yielded 100% public water supply coverage for residents. About half of the respondents (48.7%) reduced their water use by minimizing the water used for washing, and a slightly higher proportion (53.5%) minimized water used for bathing. While rain harvesting was the most widespread conservation practice, with 65.3% of the respondents adopting it, the least practised conservation method is wastewater reuse, where only about 41% of the respondents adopted it. Although themajority of the respondents were literates, education did not impact their conservation practice. The age and gender of respondents played no significant role in the adoption of conservation practices. More public awareness and water education are needed to promote greater domestic water conservation among residents.

An integrated three-way decision methodology for sustainability of wastewater circularity in thermal power plants

The presence of multiple criteria for evaluating wastewater reuse applications indicates the potential usage of Multi-Criteria Decision-Making (MCDM) methods for this purpose. However, there is currently a scarcity of studies in the domain literature that utilize MCDM approaches in this application topic. This paper therefore advances the domain literature in two distinctive ways. Firstly, it analyzes and advances the reuse agenda of wastewater from thermal power plants, recognized as large-scale users of water, thus promoting greater water circularity. Secondly, it provides a methodological advance by integrating the notion of Three-Way Decision (3WD) into the computational structure of MCDM methods by introducing a middle reference point. Such an initiative results in a novel 3WD extension of the Measurement of Alternatives and Ranking according to COmpromise Solution (MARCOS) method. Additionally, this work provides a proof that the MARCOS method utilizes a compromise solution in identifying priority alternatives, along with the integration of a Weighted Aggregated Sum Product ASsessment (WASPAS) metric. An initial hypothetical example illustrates how the proposed approach augments the canonical MARCOS method, particularly in promoting the “thinking in threes” as a more natural information processing approach and the high degree of distinguishability of priorities between decision alternatives. An actual case study in a thermal power plant then demonstrates the contributions of this work. With the best-worst method used to determine the priorities of the decision attributes, the findings reveal that wastewater reuse applications achieving reduced costs for needed infrastructures, operational simplicity, technological compatibility, consumer safety and household savings are preferred by stakeholders. The 3WD-MARCOS approach identifies industrial and commercial use, municipal use, environmental restoration, and household use as the high-priority alternatives, with cooking and drinking as least preferred. These insights guide stakeholders in their design of initiatives that allocate resources for greater wastewater reuse. A comparative analysis yields high consistency of these findings with similar MCDM methods. In addition, the efficacy of the novel 3WD-MARCOS method highlights its potential in handling MCDM problems, including those promoting water circularity.

Мікробіологічна оцінка стічних вод промислових підприємств м. Києва та Київської області

The aim: industrial wastewater microbiological monitoring and its effect on the drainage water condition. Purpose: microbiological monitoring of industrial wastewater and its impact on the state of surface waters. Materials and methods: wastewater quality evaluation was performed according to the parameters: the lactose-positive coliforms (LPC) count, the coli index, coliphages count and the pathogenic enterobacteria presence. Results: wastewater (WW) treated with full biological treatment and disinfection, UV radiation, chlorination and the cleansing structures use was studied. Industrial WW samples met the 1-2 quality class requirements. 7 food processing wastewater samples did not meet the discharge into an open water requirements in terms of LCP count, which was in the range from 2300 CFU/dm3 to 46000 CFU/dm3, it indicates water fecal pollution. At the same time, according to the coliphages count, these samples belonged to the 2nd quality class. Surface water samples comparative analysis before and after the industrial wastewater discharge shows that the investigated wastewater discharge did not lead to surface watercourse microbiological contamination. Conclusions: according to the 41 industrial wastewater reuse samples microbiological quality monitoring results for the period January 2021-June 2023, 34 WW samples were met the 1-2 quality class requirements, which indicates their satisfactory purification and the discharge possibility into an open water body. 7 samples did not meet the LCP number requirement, which indicates poor-quality purification and their fecal contamination. It was established that the surface watercourse before and after the reuse wastewater discharge, according to the LCP count, the coli index, coliphages count belong to the 1-2 quality class. The investigated industrial wastewater discharge did not exceed the allowance allocation and did not lead to surface waters microbiological contamination.

Tracking the extracellular and intracellular antibiotic resistance genes across whole year in wastewater of intensive dairy farm

Monitoring the annual variation of antibiotic resistance genes (ARGs) in livestock wastewater is important for determining the high-risk period of transfer and spread of animal-derived antibiotic resistance into the environment. However, the knowledge regarding the variation patterns of ARGs, especially intracellular ARGs (iARGs) and extracellular ARGs (eARGs), over time in livestock wastewater is still unclear. Herein, we conducted a year-round study to trace the profiles of ARGs at a Chinese-intensive dairy farm, focusing on the shifts observed in different months. The results showed significant differences in the composition and variation between iARGs and eARGs. Tetracycline, sulfonamide, and macrolide resistance genes were the major types of iARGs, while cfr was the major type of eARG. The environmental adaptations of the host bacteria determine whether ARGs appear as intracellular or extracellular forms. The total abundance of ARGs was higher from April to September, which can be attributed to the favorable climatic conditions for bacterial colonization and increased antibiotic administration during this period. Integron was found to be highly correlated with most iARGs, potentially playing a role in the presence of these genes within cells and their similar transmission patterns in wastewater. The intracellular and extracellular bacterial communities were significantly different, primarily because of variations in bacterial adaptability to the high salt and anaerobic environment. The intracellular co-occurrence network indicated that some dominant genera in wastewater, such as Turicibacter, Clostridium IV, Cloacibacillus, Subdivision5_genera_incertae_sedis, Saccharibacteria_genera_incertae_sedis and Halomonas, were potential hosts for many ARGs. To the best of our knowledge, this study demonstrates, for the first time, the annual variation of ARGs at critical points in the reuse of dairy farm wastewater. It also offers valuable insights into the prevention and control of ARGs derived from animals.

Enhanced Solubilization and Biodegradation of HMW-PAHs in Water with a Pseudomonas mosselii-Released Biosurfactant.

The treatment and reuse of wastewater are crucial for the effective utilization and protection of global water resources. Polycyclic aromatic hydrocarbons (PAHs), as one of the most common organic pollutants in industrial wastewater, are difficult to remove due to their relatively low solubility and bioavailability in the water environment. However, biosurfactants with both hydrophilic and hydrophobic groups are effective in overcoming these difficulties. Therefore, a biosurfactant-producing strain Pseudomonas mosselii MP-6 was isolated in this study to enhance the bioavailability and biodegradation of PAHs, especially high-molecular-weight PAHs (HMW-PAHs). FTIR and LC-MS analysis showed that the MP-6 surfactant belongs to rhamnolipids, a type of biopolymer, which can reduce the water surface tension from 73.20 mN/m to 30.61 mN/m at a critical micelle concentration (CMC = 93.17 mg/L). The enhanced solubilization and biodegradation of PAHs, particularly HMW-PAHs (when MP-6 was introduced), were also demonstrated in experiments. Furthermore, comprehensive environmental stress tolerance tests were conducted to confirm the robustness of the MP-6 biosurfactant, which signifies the potential adaptability and applicability of this biosurfactant in diverse environmental remediation scenarios. The results of this study, therefore, have significant implications for future applications in the treatment of wastewater containing HMW-PAHs, such as coking wastewater.

Membrane Contamination Control in the Intermittent Aeration Mode of Operation of the C-MBR Process for Campus Wastewater Reuse

Filtration backwashing is necessary for the effective operation of membrane modules, and intermittent aeration helps to remove nutrients, which can save energy and effectively control the occurrence of membrane contamination. In this study, membrane contamination was controlled using an MBR in intermittent aeration operation mode and a filtration backwash cycle; difficult organic matter and nitrogen (COD and NH4+-N) were used as the main contamination indicators for this study; and the main membrane contamination components, extracellular polymers (EPs), and soluble microbial products (SMPs) were detected. The results show that the average removal of COD and NH4+-N could reach 86.45% and 92.47%, respectively, with a 2.0 day intermittent aeration time and 9/1 min filtration backwash cycle mode, and it also helped to reduce the membrane contamination, as shown by a decrease of 11.87% in bound EPs (EPSBound) and an increase of only 5.32% in SMPs. Microbiological analyses revealed that Proteobacteria and Acinetobacter, as dominant bacteria (50.90%), were the main causes of membrane contamination.

Optimizing radical yield from free chlorine with tailored UV light emitting diode emission spectra

Novel UV sources, which do not contain mercury, provide the opportunity for enhancement of current oxidation technologies through spectral optimization, minimizing inefficiencies that currently limit conventional technology. Wastewater reuse is the primary full-scale application of UV advanced oxidation processes (AOPs) in practice but any background absorbance and the low molar absorption by conventional radical promoters (hydrogen peroxide) have historically limited their system efficiency, resulting in the underutilization of photons in a reactor. This bench-scale research evaluated use of longer wavelength UV light emitting diodes (265, 280, and 300 nm) matched with free chlorine to optimize the utilization of photons for advanced oxidation. Free chlorine possesses large absorption bands in the 280 to 300 nm range in basic pH waters which are common in carbon-based reuse and was used to experimentally verify quantum yields of hydroxyl radical generation across the UV LED peak emission wavelengths. pH- and wavelength-dependent fluence-based rate constants were experimentally derived using Nitrobenzene and Benzoic acid as probe compounds and evaluated to determine the contribution of the hydroxyl and chlorine radical. Reclaimed water taken from various advanced treatment steps was treated with this UV LED AOP to investigate how background absorbance affects radical generation and contaminant transformation kinetics. In addition, alternative performance metrics to evaluate hydroxyl radical production at different incident fluence rates and different rates of photon absorption at unique wavelengths across varying background UV absorbance levels were assessed.

Effect of natural organic residues on the adsorption capacity of layered silicate alumina clay

ABSTRACT Layered silicate clay can be modified with organic residues to enhance its adsorption properties and make it suitable for the removal of industrial hazardous substances in various industries. The modification process involves treating the clay with specific organic residues that can interact with and capture the targeted hazardous compounds effectively. Novel nano-composite adsorbing system was developed by inserting the products of powdered certain marine plant within the layers of layered silicate alumina clay (LS) through impregnation technique in order to form layered silicate alumina organic residue (LSOR). The SEM images showed clear agglomerations within the newly formed composite. Moreover, according to data obtained from Scherer equation extracted from XRD data all compounds under investigation were within the nanoscale. The newly prepared LSOR nano-composite showed a significant high adsorption capacity than the main reactants involved in the adsorbent formation process (LS and OR). The effects of various experimental factors were followed up using batch system, and kinetics and isotherms of CR dye adsorption were calculated accordingly. Adsorbent dosage, working temperature, and pH value all have a significant impact on CR removal percentage. Regarding the optimum conditions, the best temperature for CR adsorption onto LSOR is 40°C at a neutral pH medium. Adsorption isotherm study shows that the adsorption process could be followed up using Langmuir adsorption isotherm for OR while it follows Freundlich isotherm for LS adsorbent and can be followed up successfully by Temkin isotherm model in case of LSOR. Finally, field tests revealed that the LSOR nano-catalyst removed mixed dyes from industrial wastewater with a 93% performance. This outcome further solidifies the potential of LSOR nano-adsorbents as an eco-friendly solution for the treatment and reuse of industrial wastewater. It highlights the significant contribution of these new nano-adsorbents in promoting sustainable practices and addressing the challenges associated with industrial wastewater management.

A new understanding of somatic coliphages belonging to the Microviridae family in urban wastewater

Somatic coliphages (SC) and F-specific RNA coliphages (FRNAPH) have been included in regulations or guidelines by several developed countries as a way of monitoring water safety and the microbiological quality of shellfish harvesting waters. SC are highly diverse in their morphology, size and genome. The Microviridae family contains three genera of phages (Alphatrevirus, Gequatrovirus, and Sinsheimervirus), all having a capsid of similar morphology (icosahedral) and size (25–30 nm in diameter) to that of common pathogenic enteric viruses. Three PCR assays specific for each genus of Microviridae were designed to study these phages in raw and treated wastewater (WW) in order to gain knowledge about the diversity and prevalence of Microviridae among SC, as well as their inactivation and removal during WW treatments. Among the four wastewater treatment plants (WWTPs) monitored here, two WWTPs applied disinfection by UV light as tertiary treatment. First, we noticed that Microviridae represented 10 to 30 % of infectious SC in both raw and treated WW. Microviridae appeared to behave in the same way as all SC during these WW treatments. As expected, the highest inactivation, at least 4 log10, was achieved for infectious Microviridae and SC in both WWTPs using UV disinfection. PCR assays showed that the highest removal of Microviridae reached about 4 log10, but the phage removal can vary greatly between WWTPs using similar treatments. This work forms the basis for a broader evaluation of Microviridae as a viral indicator of water treatment efficiency and WW reuse.

A new evaluation framework for the assessment of wastewater heat recovery potential coupled with wastewater reuse

Abstract The integration of wastewater heat recovery (WWHR) and wastewater reuse offers a numerous advantage, making its application possible in various sectors. Nevertheless, this concept faced challenges to the identification of appropriate location. Existing research lacks comprehensive evaluation methods that encompass a various factor for effective decision-making. This study introduces a new evaluation framework that involves different aspects, including thermal energy potential and spatial distribution analysis. The novelty of this research lies in its unique focus on the combination of WWHR and wastewater reuse. Moreover, it introduces a structured evaluation framework that considers multiple criteria and expert opinions, enhancing decision-making precision. Multi-criteria decision analysis (MCDA) was applied to select assessment criteria, which were categorized into three aspects: water–energy supplier, water–energy consumers, and water–energy station. The relative importance of criteria was determined using the analytical hierarchical process (AHP). The results of the AHP highlight significance of factors: treated wastewater flow rate; treated wastewater temperature; water–energy supply distance, and type of water–energy consumer. These factors were assigned weight values of 0.297, 0.186, 0.123, and 0.096, respectively. It is emphasizing their influence in the decision-making process that potential locations depend on the water–energy supplier and water–energy consumer as supply and demand sources.

An Overview of Wastewater Treatment and Reuse in The Gulf Cooperation Council Countries

The human population generates a substantial amount of waste, and if it is discarded without any treatment it can lead to environmental degradation. This is commonly executed by discharging substantial amount of untreated wastewater in the waterways. Wastewater can be generated from numerous locations but for this review the principal areas concerned are municipalities and industries. The focus of the current study relies on performing a thorough review on expressing the benefits of treating wastewater, assessing Gulf Cooperation Council (GCC) reuse regulations associated with wastewater reuse, identifying different wastewater treatment technologies, and evaluating previous research implemented on this field across the GCC region. Various case studies about treatment technologies and reuse regulations are analyzed in this review for each country within the GCC. The findings show that treating wastewater holds many benefits such as reducing environmental pollution and can aid in helping nations with limited access to fresh water to meet their demand. The technologies for treating wastewater are discussed, such as: conventional filtration, chemical, biological treatment, and different membrane technologies. The review conveys that although treating water has many benefits, there are still many challenges associated with the cost, public perception, and management policies that need to be resolved. To improve wastewater treatment policies effective management can show greater potential for mitigating the freshwater shortage in the GCC countries. Also, since each GCC country has different policies regarding wastewater management, more research should be conducted in the future to adapt as the GCC territory is competing to produce new wastewater treatment plants to accommodate their growing demand for fresh water.

Multi-target assessment of advanced oxidation processes-based strategies for indirect potable reuse of tertiary wastewater: Fate of compounds of emerging concerns, microbial and ecotoxicological parameters

Two advanced oxidation processes (AOPs), namely ozone/H2O2 and UV/H2O2, were tested at pilot scale as zero-liquid-discharge alternative treatments for the removal of microbiological (bacteria and viruses), chemical (compounds of emerging concern (CECs)) and genotoxic responses from tertiary municipal wastewater for indirect potable reuse (IPR). The AOP treated effluents were further subjected to granular activated carbon (GAC) adsorption and UV disinfection, following the concept of multiple treatment barriers. As a reference, a consolidated advanced wastewater treatment train consisting of ultrafiltration, UV disinfection, and reverse osmosis (RO) was also employed.The results showed that, for the same electrical energy applied, the ozone/H2O2 treatment was more effective than the UV/H2O2 treatment in removing CECs. Specifically, the ozone/H2O2 treatment, intensified by high pressure and high mixing, achieved an average CECs removal efficiency higher than UV/H2O2 (66.8% with respect to 18.4%). The subsequent GAC adsorption step, applied downstream the AOPs, further improved the removal efficiency of the whole treatment trains, achieving rates of 98.5% and 96.8% for the ozone/H2O2 and UV/H2O2 treatments, respectively. In contrast, the ultrafiltration step of the reference treatment train only achieved a removal percentage of 22.5%, which increased to 99% when reverse osmosis was used as the final step.Microbiological investigations showed that all three wastewater treatment lines displayed good performance in the complete removal of regulated and optional parameters according to both national and the European Directive 2020/2184. Only P. aeruginosa resulted resistant to all treatments with a higher removal by UV/H2O2 when higher UV dose was applied. In addition, E. coli STEC/VTEC and enteric viruses, were found to be completely removed in all tested treatments and no genotoxic activity was detected even after a 1000-fold concentration.The obtained results suggest that the investigated treatments are suitable for groundwater recharge to be used as a potable water source being such a procedure an IPR. The intensified ozone/H2O2 or UV/H2O2 treatments can be conveniently incorporated into a multi-barrier zero-liquid-discharge scheme, thus avoiding the management issues associated with the retentate of the conventional scheme that uses reverse osmosis. By including the chemical cost associated with using 11–12 mg/L of H2O2 in the cost calculations, the overall operational cost (energy plus chemical) required to achieve 50% average CECs removal in tertiary effluent for an hypothetical full-scale plant of 250 m3/h (or 25,000 inhabitants) was 0.183 €/m3 and 0.425 €/m3 for ozone/H2O2 and UV/H2O2 treatment train, respectively.

Transforming Dye Molecules into Electrochemical Allies: Direct Red 80 as a Dual-Functional Electrolyte Additive for Dendrite-Free Aqueous Zinc-Ion Batteries.

Despite the numerous advantages of abundant zinc resources, low redox potential, and affordability, aqueous zinc-ion batteries (AZIBs) currently face limitations due to dendritic growth and side reactions. This study explores the use of low-cost and efficient anionic dyes, specifically Direct Red 80 (DR80) as dual-functional electrolyte additives to enhance the electrochemical performance of AZIBs and facilitate the reuse of dye wastewater. Experimental and theory calculation results all demonstrate that the DR80 molecules readily adsorb onto the surface of the zinc anode, creating a stable and robust solid electrolyte interphase layer. This layer acts as a protective barrier, effectively mitigating H+ attacks and reducing both hydrogen evolution and corrosion reactions. Additionally, it covers any initial protrusions on the zinc anode, preventing the occurrence of the "tip-effect" phenomenon and limiting access of water to the zinc anode, thereby minimizing water decomposition. Moreover, the sulfonic acid groups of DR80 molecules displace some water molecules in [Zn(H2O)6]2+, disrupting the original solvent sheath and reducing water decomposition. Especially, using the DR80 additive, the Zn/Zn cell reaches an impressive cycle life of 1500 h at 2 mA cm-2@1 mAh cm-2. Given the low cost and widespread availability, this additive shows great potential in the future practical implementation of AZIBs.