Advanced Wastewater Treatment Research Articles

Sustainable Water Management Practices at ETUT: Innovations and Policies

The paper delves into the water management strategies of Oguz Han Engineering and Technology University of Turkmenistan (ETUT), emphasizing sustainable practices and regulatory compliance. ETUT employs various innovative techniques like rainwater collection through rain gardens, permeable pavement, and cisterns to mitigate runoff and enhance water quality. Rainwater is stored for irrigation, reducing reliance on municipal sources and contributing to groundwater recharge. A water-recycling program repurposes rainwater and fountain water, while innovative structures promote plant growth and water conservation by condensing atmospheric moisture. The university utilizes advanced wastewater treatment methods incorporating plants and microorganisms to purify water efficiently. Complying with national regulations ensures safe drinking water provision and resource protection. Regular monitoring aids in assessing policy effectiveness, fostering continuous improvement. ETUT's commitment to sustainability and environmental stewardship is reflected in its comprehensive water conservation program, fostering a culture of innovation and responsibility within the university community.

Photo-electrochemical decomplexation of cobalt complexes and enhanced cobalt recovery through electrified membranes

The increasing presence of cobalt-chelated species in semiconductor manufacturing poses significant challenges for wastewater treatment because of their structural stability and high solubility. Efficient decomplexation of these metal–ligand complexes is critical for mitigating heavy metal pollution and enabling resource recovery. This study investigates the (photo)electrochemical decomplexation of cobalt-ethylenediaminetetraacetic acid (Co-EDTA) complexes using a TiO2-encapsulated electrified carbon membrane, with a focus on cobalt recovery. Compared to electrochemical oxidation alone, the photoelectrochemical (PEC) system with 365 nm UV-LED illumination demonstrated better performance, achieving over 90 % EDTA-Na2 removal within 20 min and approximately 50 % Co-EDTA decomposition within 180 min. Kinetic analysis confirmed enhanced reaction rates under PEC conditions, and system robustness was validated across varying applied voltages and electrolyte concentrations, as well as real-world semiconductor wastewater. Mechanistic studies revealed that the PEC process is driven by the generation of hydroxyl radicals (•OH), formed through the interaction of photoinduced electron-hole pairs with surface hydroxyl groups on the TiO2 membrane. These radicals facilitate stepwise decomplexation, breaking down Co-EDTA complexes and releasing cobalt ions. This work highlights the potential of TiO2 electrified membrane-based photo-electrochemical systems for efficient decomplexation and cobalt recovery, offering a sustainable solution for advanced wastewater treatment and resource recovery.

Influence of coexisting anions on the one-step electrochemical reduction and precipitation removal of Cr(VI): Implications for advanced wastewater treatment

Electroreduction of Cr(VI) coupled with in-situ precipitation of Cr(III) on the cathode is a promising method for removing Cr(VI) from wastewaters. However, the influence of coexisting anions in wastewaters on the electrochemical removal process remains unclear. This study investigated the impact of common inorganic anions, including nitrate (NO3−), chloride (Cl−), phosphate (PO43−) and sulfate (SO42−), on the electrochemical removal processes of Cr(VI). The results indicated that HCrO4− was directly electrochemically reduced to Cr3+, and the OH− generated through electro-mediated water reduction could complex with Cr3+, thereby transforming Cr3+ into chromium hydroxide (Cr(OH)3) coated at cathode. Coexisting anions would partially penetrate the alkaline Cr(III) complexes, inhibiting the formation of Cr(OH)3 passivation layer and promoting the electroreduction of Cr(VI), whose penetration ability followed the order of SO42− > PO43− > Cl− > NO3−. Both the inhibitory effect on Cr(III) precipitation and promoting effect on Cr(VI) reduction were intensified with increasing concentrations of these anions in the range of 1−100 mmol L−1. Accordingly, after electrolysis of 10 mg L−1 Cr(VI) at an initial pH of 3.0 and −0.2 V (vs. Ag/AgCl), the highest electrochemical reduction ratio of Cr(VI) (99.9%) was achieved in the presence of 100 mmol L−1 SO42−, while the total Cr removal ratio was minimal (3.3%). In contrast, the presence of NO3− at 1 mmol L−1 resulted in a nearly lowest reduction ratio of Cr(VI) (92.9%), with the maximum total Cr removal ratio (92.8%). These findings provide new insights into the electrochemical removal mechanisms of Cr(VI) in complex solution environments.

Electrochemical Methods for Nutrient Removal in Wastewater: A Review of Advanced Electrode Materials, Processes, and Applications

In response to the increasing global water demand and the pressing environmental challenges posed by climate change, the development of advanced wastewater treatment processes has become essential. This study introduces novel electrochemical technologies and examines the scalability of industrial-scale electrooxidation (EO) methods for wastewater treatment, focusing on simplifying processes and reducing operational costs. Focusing on the effective removal of key nutrients, specifically nitrogen and phosphorus, from wastewater, this review highlights recent advancements in electrode materials and innovative designs, such as high-performance metal oxides and carbon-based electrodes, that enhance efficiency and sustainability. Additionally, a comprehensive discussion covers a range of electrochemical methods, including electrocoagulation and electrooxidation, each evaluated for their effectiveness in nutrient removal. Unlike previous studies, this review not only examines nutrient removal efficiency, but also assesses the industrial applicability of these technologies through case studies, demonstrating their potential in municipal and industrial wastewater contexts. By advancing durable and cost-effective electrode materials, this study emphasizes the potential of electrochemical wastewater treatment technologies to address global water quality issues and promote environmental sustainability. Future research directions are identified with a focus on overcoming current limitations, such as high operational costs and electrode degradation, and positioning electrochemical treatment as a promising solution for sustainable water resource management on a larger scale.

Luminescent Multifunctional Nanomaterials: Capacitive Removal and Enhanced Detection Efficiency of Heavy Metals Ions for Advanced Water and Wastewater Treatment Application

AbstractIn recent years, heavy metal ions pollution in the industrialized environment of the societies threaten human health that flaunt ill‐sorted blueprints in freshwater resources obviously. The paradigm of designing luminescent multifunctional nanomaterials finds directions to the strategies of synthesizing cost‐effective, green, and versatile nanomaterials not only for detection, but also removal process of heavy metal ions in large scale applications. Among them, discovering the advances of luminescent multifunctional nanomaterials provides broad types of biomaterials, polymers and porous nanoparticles that grabs focal of investigations over the past several years due to their unique advantages such as enhanced detection efficiency with lowest limit of detection (LOD), minimum ions interference in versatile removal process, fast responsivity and selectivity as outstanding as unique physicochemical properties. This review paper tries to highlight the paradigm of principles for design, development, and utilization of luminescence nanomaterials for considering fundamental detection and removal mechanisms of heavy metal ions. In particular, these nanomaterials increase the remediation quality that are tackled in detail by focusing on opportunities and challenges in the field. Finally, design methods of these nanomaterials and concentrating on empowered detection and removal efficiency for heavy metals ions highlights novel prospective and strategies for largescale applications.

Predicting flushed wet wipe emissions into rivers

Flushed wet wipes pose a significant pollution risk to river systems at both macro and micro levels. However, the link between their emissions and environmental contamination remains unclear. Here we integrated emissions-based modelling with existing data on wet wipe disposal and microfibre generation to predict the quantity of emissions entering river systems and the transport pathways involved. Results indicate that wastewater pathways, including sewer overflows, wastewater treatment plants, and agricultural runoff, are major conduits for these pollutants. Despite advanced wastewater treatment, substantial microfibre emissions still enter the environment. Extrapolating to larger scales reveals wet wipe pollution as an international issue requiring urgent attention. This research offers a comprehensive modelling framework applicable to various wastewater pollutants, providing valuable insights for policymakers and the water industry. Improved data on wet wipe disposal, fate, and spatially distributed wastewater systems are necessary to pinpoint their environmental risks more accurately.

Robust PD/A biofilms sustain advanced real municipal wastewater treatment: Reinforcement of interspecific communication and electron transfer

In this study, a robust partial denitrification/anammox (PD/A) biofilm system was efficiently established within merely 83 days using solely conventional activated sludge as the inoculum, employing a multivariate regulation strategy involving the addition of biofillers, optimization of municipal wastewater feeding ratios, prolongation of hydraulic retention time, and introduction of hydrazine. The performance variability of PD/A system within a long-term, intricate mainstream substrate environment was further investigated by incrementally elevating municipal wastewater proportion (50 % → 75 % → 100 %). The results demonstrated that PD/A system ultimately achieved an impressive total nitrogen removal efficiency of 93.6 % and an effluent total nitrogen concentration of 8.6 mg/L, accompanied by anammox contributing over 85 % to nitrogen removal. The biofilm’s layered spatial structure nurtured Candidatus Brocadia, enabling it to reach an abundance of 2.5 % under high real municipal wastewater loading. Metabolic function analyses revealed that biofilm enhanced the abundance of genes associated with interspecies electron transfer and quorum sensing communication in PD/A consortia after prolonged exposure to municipal wastewater. These findings underscore the significances of interspecific interactions, bacterial communications, and synergistic metabolic traits within PD/A biofilm systems in the stabilization of real municipal wastewater treatment.

Impacts of blending advanced treated water and traditional groundwater supply on lead and copper concentrations and microbial diversity in premise plumbing

In response to stresses on water demands, some regions augment conventional drinking water sources with alternative water supplies such as desalinated seawater and reclaimed wastewater. The advanced treatment of wastewater by reverse osmosis, microfiltration, and advanced oxidation processes can produce high quality water for potable uses. However, if not appropriately stabilized, the resulting water can be corrosive to metal-based distribution pipes and plumbing materials. We conducted long-term premise plumbing pipe loop experiments with copper pipes containing lead solder to test the impact of the introduction of advanced treated water on the water quality. Advanced treated water (ATW) originally at low pH (<7) and low alkalinity (<10 mg/L as CaCO3) was stabilized with a calcite contactor before being blended with baseline ground water (BLW). The effects of percentages of ATW on the release of lead and copper and on the changes in the microbial diversity were monitored. Experiments monitored metal release from pipes receiving (1) only BLW, (2) a series of blends of BLW and ATW that gradually increased from 25 % to 100 % ATW, and (3) an abrupt switch from BLW to 100 % ATW. Introducing 100 % ATW dramatically increased lead release and simultaneously decreased copper release. Pipe scale analysis showed that the introduction of ATW had destabilized sulfate-containing pipe scales, which exposed the copper pipe surface to galvanic corrosion. The dissolution of scale material was associated with a significant decrease in sulfate concentration in the 100 % ATW which was in agreement with theoretical solubility calculations. The impact of blending ATW on microbial diversity was studied via 16S rRNA gene amplicon sequencing. The composition of the microbial communities changed significantly after water was in contact with the copper pipes in experiments with both BLW and ATW. The type of water recirculating in the pipes affected the structure of the microbial community. The results from this study can be useful for water utilities that are considering potable reuse as they develop strategies to mitigate any adverse impacts of water quality changes.

Advanced Wastewater Treatment: Synergistic Integration of Reverse Electrodialysis with Electrochemical Degradation Driven by Low-Grade Heat

The reverse electrodialysis heat engine (REDHE) represents a transformative innovation that converts low-grade thermal energy into salinity gradient energy (SGE). This crucial form of energy powers reverse electrodialysis (RED) reactors, significantly changing wastewater treatment paradigms. This comprehensive review explores the forefront of this emerging field, offering a critical synthesis of key discoveries and theoretical foundations. This review begins with a summary of various oxidation degradation methods, including cathodic and anodic degradation processes, that can be integrated with RED technology. The degradation principles and characteristics of different RED wastewater treatment systems are also discussed. Then, this review examines the impact of several key operational parameters, degradation circulation modes, and multi-stage series systems on wastewater degradation performance and energy conversion efficiency in RED reactors. The analysis highlights the economic feasibility of using SGE derived from low-grade heat to power RED technology for wastewater treatment, offering the dual benefits of waste heat recovery and effective wastewater processing.

Enhanced peroxymonosulfate activation for antibiotic and heavy metal removal using ZIF-67-derived magnetic Ni/Co-LDH@NC: Bimetallic electronic synergy and oxygen vacancy effects

Designing advanced bimetallic catalysts is essential to improving peroxymonosulfate (PMS) activation. Herein, a novel magnetic nickel/cobalt-layered double hydroxide decorated nitrogen-doped carbon (Ni/Co LDH@NC) catalyst we synthesized using carbonized ZIF-67 as a template for simultaneous removal of sulfamethoxazole (SMX) and Pb(Ⅱ) by PMS activation. The synthesized Ni/Co LDH@NC achieved complete degradation of SMX within 20 min and adsorbed Pb(Ⅱ) at 90.3 mg g−1 in 2 h. Notably, in simulated mixed wastewater, Ni/Co LDH@NC removed 100 % of SMX and simultaneously absorbed 84 % of Pb(Ⅱ) within 60 min. Density functional theory (DFT) studies revealed that synergistic Ni-Co sites and “bridging oxygen” vacancies enhanced electron transfer to PMS, facilitating O-O bond cleavage. The catalyst maintained high performance after four cycles, with over 85 % SMX degradation and 80 % Pb(Ⅱ) removal. This study highlights the potential of MOF-derived catalysts for efficient, simultaneous remediation of antibiotic and heavy metal pollutants, contributing to advanced wastewater treatment.

Practical implications of adding powdered activated carbon in advanced wastewater treatment for process and plant design

ABSTRACT The addition of powdered activated carbon (PAC) in advanced wastewater treatment is increasingly recognized for its effectiveness in removing micropollutants from secondary effluents. This study investigates the implications of PAC dosing on treatment performance, particularly in terms of natural and effluent organic matter (OM) removal, turbidity reduction, and sludge characteristics. Results indicate that while PAC incorporation significantly enhances the adsorption of OM, it necessitates higher coagulant dosages to achieve comparable or improved turbidity levels. The study also reveals that lower pH levels facilitate the removal of OM, thereby increasing the availability of adsorption sites on PAC for micropollutants. Moreover, PAC addition results in the formation of larger, denser flocs that settle faster, leading to a reduction in sludge volume by approximately 20%. However, the increased coagulant demand and the subsequent rise in sludge volume highlight the need for the optimized process design to balance treatment efficiency with operational costs. This research provides valuable insights for the design and operation of wastewater treatment plants, emphasizing the importance of tailored coagulant dosing and process adjustments when integrating PAC into existing treatment frameworks.

Advancing wastewater treatment: The efficacy of carbon-based electrochemical platforms in removal of pharmaceuticals

The study addresses the efficiency of innovative biochar- and g-C3N4-coated electrochemical platforms in removing selected pharmaceuticals and their metabolites from wastewater, with a focus on cost-effective and scalable materials. Analysis of effluent from the wastewater treatment plant revealed significant concentrations of 25 pharmaceuticals, highlighting the plant’s limited treatment efficacy. Notably higher levels of Telmisartan, Tramadol, and Diclofenac were found. The novelty of this work lies in the use of biochar- and g-C3N4-coated Raschig rings and glass beads as efficient electrochemical anodes offering high degradation capabilities. Adsorption-only tests (without voltage load) confirmed that no significant pharmaceutical removal occurs without electrochemical activation, highlighting the importance of electrochemical degradation. For the first time, we observed the formation of hydroxyl radicals (•OH) and singlet oxygen (1O2) during the electrochemical degradation process using g-C3N4-coated anodes, significantly enhancing degradation efficiency. The biochar-coated Raschig rings achieved over 80 % removal efficiency for all tested pharmaceuticals, with a power consumption of 85.2 kWh/m3. In comparison, biochar-coated beads exhibited a removal efficiency ranging from 9 % to 99 %, consuming 75 kWh/m3, while g-C3N4-coated rings showed the lowest performance at an energy consumption of 45 kWh/m3. These findings demonstrate the potential of both, biochar- and g-C3N4-based electrochemical platforms as a viable, scalable solution for advanced wastewater treatment, particularly for pharmaceutical degradation.

Single-atom cobalt enables efficient catalytic ozonation for advanced wastewater treatment: Mechanisms and application

Heterogeneous catalytic ozonation (HCO) triggered by single-atom catalysts (SACs) is an emerging and promising advanced wastewater treatment technology. The catalytic ozonation mechanisms involving single-atom sites and the application of SAC-based HCO require further exploration. Herein, a single-atom Co catalyst with Co-N4 active sites was synthesized for HCO. Oxalic acid (OA) and p-hydroxybenzoic acid (pHBA) with different structural and chemical properties were utilized as the model contaminants. Compared with ozonation and Co nanoparticle-based HCO, single-atom Co-based HCO exhibited superior removal for the two model pollutants, with the removal rate constants of 0.098 and 0.076 min−1 for OA and pHBA, respectively. In the single-atom Co-based HCO, ozone was decomposed and converted to nonradical ROS of surface-adsorbed atomic oxygen (*Oad) and singlet oxygen (1O2). OA was mainly removed on the catalyst surface, relying on the adsorption by the catalyst and the oxidation of *Oad, while electron-rich pHBA was oxidized by O3 and 1O2 in solution. Furthermore, using 3–5 mm Al2O3 pellets as the carrier, single-atom Co-doped carbon-Al2O3 pellets were fabricated and applied for the advanced treatment of landfill leachate, and the COD decreased from 110 mg/L to 38 mg/L after treatment. This work provided new insights into the oxidation mechanisms and applications of SAC-based HCO.

Mechanism of Enhanced Fluoride Adsorption Using Amino-Functionalized Aluminum-Based Metal–Organic Frameworks

Due to the increasing fluoride concentrations in water bodies, significant environmental concerns have arisen. This study focuses on aluminum-based materials with a high affinity for fluorine, specifically enhancing metal–organic frameworks (MOFs) with amino groups to improve their adsorption and defluorination performance. We systematically investigate the factors influencing and mechanisms governing the adsorption and defluorination behavior of amino-functionalized aluminum-based MOF materials in aqueous environments. An SEM, XRD, and FT-IR characterization confirms the successful preparation of NH2-MIL-101 (Al). In a 10 mg/L fluoride ion solution at pH 7.0, fluoride ion removal efficiency increases with the dosage of NH2-MIL-101 (Al), although the marginal improvement decreases beyond 0.015 g/L. Under identical conditions, the fluoride adsorption capacity of NH2-MIL-101 (Al) is seven times greater than that of NH2-MIL-101 (Fe). NH2-MIL-101 (Al) demonstrates effective fluoride ion adsorption across a broad pH range, with superior fluoride uptake in acidic conditions. At a fluoride ion concentration of 7 mg/L, with 0.015 g of NH2-MIL-101 (Al) at pH 3.0, adsorption equilibrium is achieved within 60 min, with a capacity of 31.2 mg/g. An analysis using adsorption isotherm models reveals that the fluoride ion adsorption on NH2-MIL-101 (Al) follows a monolayer adsorption model, while kinetic studies indicate that the predominant adsorption mechanism is chemical adsorption. This research provides a scientific basis for the advanced treatment of fluoride-containing wastewater, offering significant theoretical and practical contributions.

Titania stabilized Pickering emulsion for photocatalytic degradation of o-xylene

Efficient removal of insoluble volatile organic compounds (VOCs) from wastewater is a significant environmental challenge. In this work, we exploit the synergistic effect of photocatalysis and the high interfacial area of TiO2-stabilized Pickering emulsion to achieve efficient degradation of o-xylene, typically present in wastewater discharged from many industries. Interfacial photocatalysis is carried out by considering o-xylene in water Pickering emulsions stabilized by commercial titania nanoparticles in a multitube non-stirred reactor setup. Stable emulsions used for catalysis are formulated by optimizing o-xylene volume fraction, TiO2 concentration, pH, and homogenization conditions. The influence of photocatalyst loading, emulsion droplet size, and reaction conditions are systematically examined to determine their influence on the rate of photocatalytic degradation of o-xylene. Due to enhanced photocatalytic activity compared with conventional stirred batch photocatalysis, the TiO2-stabilized Pickering emulsion is found to increase the degradation rate and removal efficiency of o-xylene significantly. Furthermore, the Pickering emulsion stability during the photocatalytic process is studied, demonstrating the capacity of the emulsions to maintain stability and catalytic activity over a longer time period. The distinctive characteristics of Pickering emulsions – excellent storage stability and enhanced photocatalytic activity – make them a promising option for advanced wastewater treatment. The findings lead to the development of ecologically acceptable and sustainable VOC degrading strategies, which might be used in industrial and home wastewater treatment systems.

Understanding the interaction between soil ORP and enzyme activity: How does wetland type affect constructed wetland performance for the advanced treatment of swine wastewater?

Constructed wetlands (CWs) are widely used for the advanced treatment of swine wastewater. Wetland type is the most critical parameter for engineering applications; therefore, the performance of horizontal/vertical subsurface flow CWs (HSFCWs and VSFCWs) was explored over one year of operation. The effects of five antibiotics (40 μg/L each), copper (Cu, 1.0 mg/L), and their combination on CW performance and soil oxidation–reduction potential (ORP) and enzyme activity were investigated. The annual removal efficiencies of HSFCWs and VSFCWs for total organic carbon (TOC), nitrogen, and phosphorus were 72.03 %–84.49 % and 87.15 %–90.72 %, for antibiotics were 91.35 %–99.52 % and 87.33 %–99.57 %, and for Cu were 97.37 %–97.44 % and 95.52 %–96.85 %, respectively. The CWs removed antibiotics through substrate adsorption, plant absorption, and biodegradation. Total antibiotic residues in HSFCW and VSFCW soils ranged from 6.29 to 17.31 and 24.57 to 589.07 μg/kg, respectively, and enrofloxacin and roxithromycin posed medium and high risks in VSFCW non-rhizosphere soil. The amount of residual antibiotics in Phragmites australis parts was in the order of fibrous roots > rhizomes > aboveground. ORP and enzyme activities were greater in rhizosphere soil than in non-rhizosphere soil and greater in the VSFCWs than in the HSFCWs. CW performance and soil enzyme activities decreased under the stress of antibiotics and coexistence of antibiotics and Cu. These findings advance our knowledge of CW design, elucidate the unique advantages of CWs, and offer efficient operation strategies for swine wastewater advanced treatment, helping researchers recognize the adverse effects of antibiotics on CWs.

Photocatalytic Fenton-like degradation of Acid Green 25 by novel aluminum nanoferrites with persulfate: Optimization by response surface methodology

Magnetic nanomaterials are gaining increasing attention for their catalytic properties and ease of recovery, making them promising candidates for the degradation of various organic pollutants. In this study, AlFe2O4 nanoparticles were employed for the first time in photocatalytic wastewater treatment. The study focused on removing Acid Green 25 anthraquinone dye through persulfate activation under UV-Visible light. AlFe2O4 nanoparticles were synthesized via sol-gel auto-combustion method and characterized by various techniques (XRD, SEM, EDX, VSM, Raman and FTIR). Moreover, statistical analysis of the experimental data confirmed the strong performance of the RSM model in accurately representing the photocatalytic process. Under optimal conditions including persulfate and catalyst concentrations of 0.3 g/L and 0.83 g/L respectively, a solution pH of 3 and 45 minutes of contact time, a 96 % dye removal rate was achieved. The remaining persulfate concentration was 60 % and fully depleted within 90 minutes, indicating efficient activation by AlFe2O4 photocatalyst. The activation process effectively suppressed electron-hole recombination, enhancing the overall efficiency. Scavenger experiments further identified surface-bound radicals and photogenerated holes as the main reactive species. A degradation mechanism for AG25 dye via a photocatalytic Fenton-like process was proposed, highlighting dual synergistic catalysis in the dye degradation. Ecotoxicity assessments using Vibrio fischeri bioassay revealed a significant reduction in toxicity after treatment with AlFe2O4/PS/UV-Vis system. The stability of AlFe2O4 was demonstrated over five degradation cycles. The findings open new perspectives for the use of AlFe2O4 in advanced wastewater treatment technologies, positioning it as a promising material for the degradation of persistent pollutants.

Effects of Hydraulic Retention Time on Removal of Cr (VI) and p-Chlorophenol and Electricity Generation in L. hexandra-Planted Constructed Wetland-Microbial Fuel Cell.

Hexavalent chromium (Cr (VI)) and para-chlorophenol (4-CP) are prevalent industrial wastewater contaminants that are recalcitrant to natural degradation and prone to migration in aquatic systems, thereby harming biological health and destabilizing ecosystems. Consequently, their removal is imperative. Compared to conventional chemical treatment methods, CW-MFC technology offers broader application potential. Leersia hexandra Swartz can enhance Cr (VI) and 4-CP absorption, thereby improving wastewater purification and electricity generation in CW-MFC systems. In this study, three CW-MFC reactors were designed with L. hexandra Swartz in distinct configurations, namely, stacked, multistage, and modular, to optimize the removal of Cr (VI) and 4-CP. By evaluating wastewater purification, electrochemical performance, and plant growth, the optimal influent hydraulic retention time (HRT) was determined. The results indicated that the modular configuration at an HRT of 5 days achieved superior removal rates and power generation. The modular configuration also supported the best growth of L. hexandra, with optimal photosynthetic parameters, and physiological and biochemical responses. These results underscore the potential of modular CW-MFC technology for effective detoxification of complex wastewater mixtures while concurrently generating electricity. Further research could significantly advance wastewater treatment and sustainable energy production, addressing water pollution, restoring aquatic ecosystems, and mitigating the hazards posed by Cr (VI) and 4-CP to water and human health.

Low-energy advanced wastewater treatment using submerged nanofiltration

The use of submerged nanofiltration (NF) membranes in wastewater treatment is an emerging process that produces high-quality recycled water with low energy consumption. This study aimed to identify the potential of coupling anaerobic digestion with this low-energy advanced wastewater treatment using submerged NF membranes. The direct NF of primary wastewater effluent using four types of commercial NF membranes resulted in progressive membrane fouling over 4 d. However, almost all the foulants contributing to hydraulic loss were removed by one-swipe sponge cleaning. This indicated that the major foulants were generally deposited on the membrane surface during direct NF. The membrane fouling speed varied during the long-term test depending on the feed wastewater quality. Although the transmembrane pressure increased by up to 50 kPa in every filtration cycle (4–7 d), sponge cleaning removed all the membrane foulants, resulting in >30 d of operation without chemical cleaning. The NF concentrates (four times concentrated wastewater) were then used for biogas production in an anaerobic digester. The volume of biogas formed from the NF concentrates sufficiently compensated for the energy consumption of direct NF. This study realized a low-energy advanced wastewater treatment utilizing NF concentrates that can also be used for biogas formation.

Cardiovascular Drugs as Water Contaminants and Analytical Challenges in the Evaluation of Their Degradation

Cardiovascular drugs have been a burning topic in the field of environmental analytical chemistry in the last few decades. Growing modern healthcare has led to the widespread use of pharmaceuticals. Among these, antihypertensives (sartans, angiotensin-converting enzyme inhibitors) and lipid-regulating drugs (fibrates and statins) are the most frequently consumed and, thus, excreted into wastewater. Their chemical fate during conventional and advanced wastewater treatment, such as ozonation, remains unclear. Analytical chemistry, providing sample pretreatment followed by instrumental analysis, has a tremendous role in water treatment evaluation, mostly from the perspective of parent contaminants’ removals and also assessment of transformation pathways. Ultrasensitive liquid chromatography–mass spectrometry (LC-MS) systems provide many opportunities. By carefully using planned workflows for chromatographic and mass-spectrometric data processing, i.e., suspect and non-target screening approaches, LC-MS allows for the identification and structural elucidation of unknown, predicted, suspected or selected transformation products. Accordingly, some examples and case studies on selected cardiovascular drugs in this review are presented to show the applicability of the used analytical approaches and workflows.