Water Environment Research[JOURNAL]
Sun
200 papers
Statistical Optimization of Vegetable Washwater Treatment Using Electrocoagulation.
Tanoe AS, Drogui P, Khajvand M … +5 more , Palacios J, Mahy JG, Ndao A, Adjallé K, Godbout S
Water Environ Res · 2026 Jun · PMID 42338040 · Full text
This study investigates the application of electrocoagulation (EC) for treating vegetable washwater (VWW). Preliminary EC experiments were carried out to define the operational parameter ranges supporting a subsequent st...
This study investigates the application of electrocoagulation (EC) for treating vegetable washwater (VWW). Preliminary EC experiments were carried out to define the operational parameter ranges supporting a subsequent statistical optimization of the process. The optimization aimed to identify the most efficient operating conditions for pollutant removal while minimizing energy consumption. VWWs were sampled from four root vegetable washings (potatoes, leeks, and red beets). Various EC tests carried out using a 500-mL reactor and a response surface methodology of experiments enabled us to obtain optimum operating conditions for the treatment of VWW. Thus, optimal conditions of a current intensity of 0.32 A for 8.8 min with aluminum electrodes gave total suspended solid (TSS) and turbidity reduction rates of 99% and 98%, respectively, along with a total phosphorus reduction rate of 93% for Farm 1. EC VWW treatment generally met the regulatory discharge limit of 50-mg/L TSS. Only TSS of Farm 4 remained well above the limit. EC also reduced neonicotinoid insecticides present in VWW by 38%, and the true color of beet roots decreased from 283 to 60 UCV. The energy costs associated with VWW clarification treatment ranged between CAD$0.06/m and CAD$0.09/m.
A Modeling-Optimization-Validation Framework for Digital Transformation Decisions in Socio-Technical Systems: Evidence From Wastewater Treatment Projects.
Yu L, Li D, Song J … +3 more , Li L, Han W, Liu W
Water Environ Res · 2026 Jun · PMID 42333964 · Publisher ↗
Managers of socio-technical systems (STSs) lack quantitative tools to optimize digital technology (DT) selection. This study bridges this gap by developing a unified modeling-optimization-validation decision-making frame...
Managers of socio-technical systems (STSs) lack quantitative tools to optimize digital technology (DT) selection. This study bridges this gap by developing a unified modeling-optimization-validation decision-making framework, positioned as an upstream, preplanning tool complementary to operational digital twins. First, a time-varying network model is constructed with explicit mathematical definitions for task-information dynamics. Second, DT selection is formulated as a multiple-choice knapsack problem (MCKP) and solved using a genetic algorithm (GA) with formally defined fitness functions and constraints. Third, numerical simulations validate the approach. A case study of a wastewater treatment project demonstrates that the optimized DT portfolio yields an average efficiency improvement of 27.9% (calculated based on node-level productive and cost efficiency). This framework provides a transferable, quantitative basis for designing digital transformation roadmaps, offering a lower-effort alternative for initial investment prioritization compared to high-frequency operational calibration in traditional digital twins.
Valorizing Landfill Gas Condensate as an External Carbon Source for Denitrification in Sewage-Landfill Leachate Co-Treatment.
Ahmed MA, Brazil B, Zhang L … +1 more , Zhao R
Water Environ Res · 2026 Jun · PMID 42333917 · Full text
Landfill gas condensate (LFGC) is an underused byproduct that could reduce the cost and environmental impact of purchased external carbon for biological nitrogen removal. This study tested LFGC as a denitrification carbo...
Landfill gas condensate (LFGC) is an underused byproduct that could reduce the cost and environmental impact of purchased external carbon for biological nitrogen removal. This study tested LFGC as a denitrification carbon source in sequencing batch reactors (SBRs) co-treating municipal sewage and landfill leachate. Four lab-scale SBRs operated for 170 days with 98.5% sewage and 1.5% landfill leachate, supplemented with methanol, glycerin, sodium acetate, or LFGC. All reactors performed stably, achieving total nitrogen removal efficiencies of 93.1%-93.8% and effluent nitrate below 1 mg N/L. The LFGC reactor reached nitrate removal up to 99.2%, with effluent NO-N as low as 0.31 mg N/L. Although LFGC required more external COD (6.6 g COD/g NO-N removed) than the conventional carbon sources (3.6-3.7), it also enabled the shortest minimum denitrification time (2.2 h). EEM-PARAFAC and FTICR-MS analyses showed similar dissolved organic matter characteristics in all effluents, indicating that LFGC did not produce distinct fluorescent or molecular DOM signatures compared with conventional carbon sources. Overall, LFGC performed comparably to conventional liquid carbon sources while beneficially reusing a landfill byproduct.
Membrane-Based Dehydration of N-Methyl-2-Pyrrolidone-Contaminated Wastewater: Experimental and Techno-Economic Analysis.
Van Eygen G, Ibrahimi ME, Rubio LN … +4 more , Ismail N, Van Dael M, Vandezande P, Buekenhoudt A
Water Environ Res · 2026 Jun · PMID 42333878 · Publisher ↗
N-methyl-2-pyrrolidone (NMP), widely used in polymeric membrane production, generates over 50 billion liters of contaminated wastewater annually, posing major environmental and regulatory challenges. Because solvent subs...
N-methyl-2-pyrrolidone (NMP), widely used in polymeric membrane production, generates over 50 billion liters of contaminated wastewater annually, posing major environmental and regulatory challenges. Because solvent substitution is often impractical, reducing wastewater volume through dehydration is an attractive option. This study compares three membrane-based technologies, nanofiltration/reverse osmosis (NF/RO), pervaporation (PV), and membrane distillation (MD), for dehydrating aqueous mixtures of NMP and glycerol representative of industrial effluents. Tight NF/RO membranes (AFC80 and AFC99) quickly lost flux and rejection at higher solvent contents, limiting use to initial concentration steps at high water fractions. Pervaporation with an S-3011 membrane achieved 20-30 kg m h flux and 90.4% water recovery, while membrane distillation with a PE membrane yielded 10-15 kg m h flux and up to 83.7% recovery. Technoeconomic analysis showed that membrane distillation and, to a lesser extent, pervaporation outperform conventional thermal treatment processes. Membrane distillation cut costs by up to 63% compared to distillation, driven by low-cost membranes and simple operation. Overall, pervaporation and membrane distillation offer efficient and cost-effective options for NMP wastewater dehydration.
Hydrochemical and Isotopic Insights Into Source, Controlling Processes, and Quality of River Water and Groundwater in an Arid Agricultural Area, Qaidam Basin, Northwest China.
Yang N, He K, Song X … +7 more , Guo L, Zhao C, Wang G, Xiao Y, Di D, Zhang Y, Jiang W
Water Environ Res · 2026 Jun · PMID 42322057 · Publisher ↗
Water source and quality is the most important factor for region sustainable development, especially in the water-scarce arid agricultural regions. In the agricultural area of arid Qaidam Basin, water quality remains ina...
Water source and quality is the most important factor for region sustainable development, especially in the water-scarce arid agricultural regions. In the agricultural area of arid Qaidam Basin, water quality remains inadequately studied. Focusing on the Xiangride River Watershed in the southeastern Qaidam Basin, this research explores the recharge sources, hydrogeochemical evolution, and quality of river water and groundwater integrating correlation analysis, principal component analysis (PCA), and inverse geochemical modeling. Stable isotopic analysis indicates that river water and groundwater are derived from mountainous precipitation, and groundwater is recharged by lateral runoff and river seepage in the plain area. Most river water and groundwater samples exhibit relatively low TDS values of < 1000 mg/L, and groundwater exhibits more complex hydrochemistry compared with river water. Along the flow path, the hydrochemical types are marked by the HCO·Cl·SO-Na·Mg type for river water, which groundwater shows an evolution from Cl·HCO-Na·Mg to Cl·HCO·SO-Na·Ca·Mg and ultimately to HCO·Cl·SO-Na·Ca·Mg. The comprehensive analysis by PCA, major ions relationships and inverse geochemical modeling identifies that water-rock interactions including dissolution and precipitation of evaporites, carbonates, and silicates, together with cation exchange and mixing control the hydrochemical compositions. Water quality assessment based on EQWI, SAR, and Na% values classifies most river water and groundwater as "good" without obvious spatial variation, indicating that the overall water quality is adequate for domestic and agricultural uses. The attention needs to be made in certain area with relatively elevated groundwater NO . These findings provide a basis for the sustainable management of water resource in arid agricultural zones.
Computational Fluid Dynamics Reveals Mass Transfer Limitations in a Pilot-Scale Microbial Electrolysis Cell.
Guerrero-Sodric O, Navarro-Quispe RJ, Cortada-García M … +2 more , Baeza JA, Guisasola A
Water Environ Res · 2026 Jun · PMID 42318628 · Full text
The scalability of microbial electrochemical technologies (METs), particularly microbial electrolysis cells (MECs), is constrained by hydrodynamic and mass transfer limitations that hinder efficient resource recovery fro...
The scalability of microbial electrochemical technologies (METs), particularly microbial electrolysis cells (MECs), is constrained by hydrodynamic and mass transfer limitations that hinder efficient resource recovery from wastewater. This study presents a comprehensive computational fluid dynamics (CFD) model of a pilot-scale MEC (1 m), representing the largest MEC modeled to date and integrating fluid dynamics with bioelectrochemical substrate consumption. The model simulates the spatial distribution of the anolyte under various operational conditions to identify flow-induced limitations in substrate transport to anodic biofilms. Dead zones and preferential flow paths caused significant inefficiencies, resulting in poor acetate removal under laminar flow. When evaluating the influence of HRT, reaction kinetics, and diffusivity on MEC performance, simulations further underscore that reactor performance is predominantly governed by external mass transfer rather than intrinsic reaction kinetics. To mitigate transport limitations without reducing the volumetric treatment capacity, a recirculation strategy was implemented, enhancing acetate removal efficiency from 16% to 48%. Model predictions agreed well with experimental data from similar pilot-scale MECs, supporting the validity of the approach. This work is intended as a reduced-order framework to diagnose hydrodynamic and external mass transfer limitations in large-scale cassette-type MECs, offering practical insights for improving reactor design and operation.
Optimization of Aluminum Utilization in Ultrasonic-Assisted Chemical Leaching of Purified Sludge Based on Response Surface Methodology.
Li X, Zhang C, Wu D
Water Environ Res · 2026 Jun · PMID 42318599 · Publisher ↗
This study employed response surface methodology to optimize the ultrasonic-assisted chemical leaching process for the efficient extraction of aluminum from purified water sludge. Through two consecutive stages of optimi...
This study employed response surface methodology to optimize the ultrasonic-assisted chemical leaching process for the efficient extraction of aluminum from purified water sludge. Through two consecutive stages of optimizing chemical leaching parameters and ultrasound-assisted conditions, the system determines the optimal extraction conditions and evaluates the practical application potential of aluminum recovery. The results showed that the chemical leaching effect was optimal when using 2.0 mol/L sulfuric acid, with an aluminum extraction rate of 40.15%; subsequently, through ultrasound-assisted single-factor experiments combined with response surface fitting optimization, the aluminum extraction rate was significantly increased to 70.32% under the conditions of 1080 W ultrasound power, 56.53 min processing time, and 51.13°C extraction temperature.
Sol-Gel Synthesis of CaFeO Spinel Nanoparticles Using Marine Algae-Derived Calcium Oxide for Efficient Adsorption.
Bouchair A, Sayoud N, Benchouieb I … +4 more , Bousbia I, Amayreh MY, Sanil GT, Gulgun MA
Water Environ Res · 2026 Jun · PMID 42313708 · Publisher ↗
In this study, spinel CaFeO nanoparticles were fabricated for the first time via the sol-gel method using biogenic calcium oxide (CaO) derived from the marine alga Corallina elongata as a sustainable, available, and low-...
In this study, spinel CaFeO nanoparticles were fabricated for the first time via the sol-gel method using biogenic calcium oxide (CaO) derived from the marine alga Corallina elongata as a sustainable, available, and low-cost precursor. The synthesized nanoparticles were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and point of zero charge (pHpzc) analysis. Batch adsorption experiments were performed to evaluate Congo red (CR) dye removal by the fabricated spinel nanoparticles as an efficient adsorbent. The effects of pH, contact time, adsorbent dosage, and initial dye concentration were systematically optimized. Kinetic data followed the pseudo-second-order model, while equilibrium data fitted the Langmuir isotherm, confirming monolayer chemisorption on a homogeneous adsorbent surface. Thermodynamic analysis demonstrated a spontaneous, endothermic adsorption mechanism. A maximum adsorption capacity of 84.5 mg g and 94.7% CR removal were achieved within 50 min under optimized conditions, establishing marine biomass-derived CaFeO as a promising, sustainable, low-cost adsorbent for CR-contaminated wastewater remediation.
A Comparison of Biosolids Odorants and Odors Emitted from Belt Filter Press and Centrifuge Dewatering.
Vitko TG, Yin Z, Zhou Y … +1 more , Suffet IH
Water Environ Res · 2026 Jun · PMID 42313571 · Publisher ↗
Water resource recovery facilities (WRRFs) invariably question the timing and the advantages of modifying their biosolids dewatering systems from belt filter presses to centrifuges, as this change can reduce the water co...
Water resource recovery facilities (WRRFs) invariably question the timing and the advantages of modifying their biosolids dewatering systems from belt filter presses to centrifuges, as this change can reduce the water content from about 80% to 70%. The upgrade makes perfect sense keeping in mind the ever-increasing distances of transporting the biosolids to end users. However, a factor of concern that needs to be considered, besides the investment capital, is the alleged sharp increase of emitted odors by centrifuge dewatering, causing a negative public impact. This paper compares the chemical and sensory odor results from a large WRRF that originally dewatered its anaerobically digested biosolids through belt filter presses and then replaced this process with dewatering centrifuges. No major changes in the wastewater characteristics or in the unit operations occurred in the interval, which provides a unique opportunity to observe the changes in odor emissions. The results show that there is a change in the predominant chemical odorants emitted as well as a sharp increase in the variety of odor characters and intensities corresponding with the change in dewatering technology. Worst-case odorant concentrations (the maximum value observed) from belt filter press to centrifuge dewatering significantly increased from 52 to 4980 ppb for hydrogen sulfide, increased from 390 to 1100 ppb for methyl mercaptan, increased from 520 to 3200 ppb for dimethyl sulfide, and increased from 27 to 270 ppb for dimethyl disulfide. At the same time, whereas the worst-case rotten vegetable odor intensity remained the same, and earthy/musty decreased by one order of magnitude, the fecal and manure odor intensities increased by two orders of magnitude. Keeping in mind that odor intensity is reported in a log scale, these changes are significant, especially as they peak at the top end of the odor intensity scale.
Experimental Investigation of Simultaneous NaCl, SO , Turbidity, and pH Removal Using Limestone-Alumina Porous Broad-Crested Weirs.
Jabbar A, Al-Husseini TR, Ghawi AH
Water Environ Res · 2026 Jun · PMID 42309816 · Publisher ↗
Water quality deterioration in Iraqi rivers, characterized by elevated dissolved salts, sulfates, and suspended solids, represents a critical environmental challenge that conventional solid weirs cannot address. This stu...
Water quality deterioration in Iraqi rivers, characterized by elevated dissolved salts, sulfates, and suspended solids, represents a critical environmental challenge that conventional solid weirs cannot address. This study presents a systematic laboratory investigation of a porous broad-crested weir (PBCW) packed with limestone (Ls) and activated alumina (Al) in four configurations (Ls, Al, Al-Ls-Al, and Ls-Al-Ls) to achieve simultaneous removal of sodium chloride (NaCl), sulfate (SO ), turbidity, and pH correction. Experiments were conducted under four hydraulic regimes: through-flow, through-flow limit, transition flow, and overflow limit, with water samples collected at 10 intervals over 240 min. Results show that activated alumina consistently outperformed limestone for ionic removal, with the all-alumina configuration achieving peak NaCl and SO efficiencies of 10.6% and 9.8%, respectively, under through-flow limit conditions. Limestone configurations provided superior turbidity reduction (up to 69.3%) and pH correction (from 5.80 to 7.05). Among hybrid configurations, Al-Ls-Al delivered the most balanced multicontaminant performance and is recommended for practical deployment. Through-flow limit (Q = 1.85 m h, h = 10 cm) was identified as the optimal hydraulic condition across all configurations. Treatment efficiency declined progressively with time due to adsorption site saturation, with alumina exhibiting steeper decay than limestone. These results establish the PBCW as a viable passive treatment technology for decentralized, low-energy water quality improvement in water-scarce regions.
Sustainable Remediation of Antibiotic-Contaminated Groundwater Using Thermally Modified Bentonite Functionalized With Green-Synthesized Nanoparticles.
Hammood ZA, Ali ZTA
Water Environ Res · 2026 Jun · PMID 42304813 · Publisher ↗
In this study, Cono carpus leaf extract, a green antioxidant, was exploited to green-synthesize Fe/Cd nanoparticles, eliminating the need for harmful chemicals. The synthesized nanoparticles were immobilized using modifi...
In this study, Cono carpus leaf extract, a green antioxidant, was exploited to green-synthesize Fe/Cd nanoparticles, eliminating the need for harmful chemicals. The synthesized nanoparticles were immobilized using modified bentonite (MB) via thermal treatment, which improves the hydraulic properties of bentonite and makes it a suitable support material for nanoparticles, especially for continuous experiments. In a permeable reactive barrier (PRB), the synthesized nanocomposite (MB-Fe/Cd) was employed as reactive material to retain Penicillin G (PG), Kanamycin (KC), and Chloramphenicol (CP) in groundwater. The batch and continuous trials showed that the nanocomposite might enhance hydraulic characteristics and impede pollutant transfer. In addition, contaminant transport was simulated using COMSOL software. Accordingly, in the PRB method for cleaning up contaminated groundwater, the nanocomposite (MB-Fe/Cd) can be regarded as a promising reactive agent.
Pb (II) Biosorption by Ramalina conduplicans Biomass: Adsorption Behavior and Binding Mechanisms.
Singh K, Goswami RP, Kumar A … +2 more , Khati PS, Dhouni M
Water Environ Res · 2026 Jun · PMID 42304553 · Publisher ↗
This study presents a rigorous technical evaluation of the sequestration of Lead (Pb (II)), a representative potentially toxic element (PTE), using the biomass of the lichen Ramalina conduplicans Vain. Surface characteri...
This study presents a rigorous technical evaluation of the sequestration of Lead (Pb (II)), a representative potentially toxic element (PTE), using the biomass of the lichen Ramalina conduplicans Vain. Surface characterization conducted via SEM-EDX, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) confirmed that the lichen biomass possesses a heterogeneous, porous, and amorphous structure. The surface is rich in carboxyl, hydroxyl, and amino functional groups, which undergo distinct morphological transformations following Pb (II) adsorption. Batch experiments achieved a maximum removal efficiency of 99.15% at pH 5 and a dosage of 83.33 g L. Kinetic modeling via nonlinear regression identified the pseudo-second-order model (R = 0.965) as the superior fit, while nonlinear Boyd and Weber-Morris models confirmed film diffusion as the primary rate-limiting step. Equilibrium data were evaluated using five nonlinear equilibrium models, with the Hill model providing the most accurate description (R = 0.936). The Hill coefficient (n = 1.983) reveals positive cooperativity, indicating that the initial Pb (II) binding enhances the affinity of subsequent binding sites. While the Langmuir model (R = 0.894) estimated a maximum adsorption capacity (q) of 3.889 mg g, the superior fits of Hill, Redlich-Peterson, and Temkin models confirm a complex chemisorption mechanism occurring on a heterogeneous surface. Thermodynamic analysis further categorized the process as both spontaneous and endothermic. In conclusion, R. conduplicans biomass functions as a sustainable and cost-effective biosorbent for Pb (II) removal. While further optimization is required for industrial scaling, its cooperative binding mechanism and high removal efficiency highlight its potential as a green component in integrated PTE remediation strategies.
Study on the Influence of Temperature on Biogas-Coupled Anaerobic Ammonium Oxidation.
Cao Y, Ma Y, Sun Y … +3 more , Liu S, Tian X, Zhang K
Water Environ Res · 2026 Jun · PMID 42298806 · Publisher ↗
Temperature is widely recognized as a critical limiting factor for the stable operation of anaerobic ammonium oxidation (Anammox) systems, with low-temperature environments typically imposing severe inhibition on the met...
Temperature is widely recognized as a critical limiting factor for the stable operation of anaerobic ammonium oxidation (Anammox) systems, with low-temperature environments typically imposing severe inhibition on the metabolic activity of functional anaerobic ammonium oxidation bacteria (AnAOB) and the overall nitrogen removal performance. While Anammox has emerged as a promising low-carbon nitrogen removal technology for wastewater treatment, its full-scale application in temperate and cold regions is largely constrained by low-temperature suppression, and the mitigation potential of biogas coupling in this context remains poorly elucidated. To address this knowledge gap, this study systematically investigated the alleviation effect of intermittent biogas injection on low-temperature inhibition of Anammox systems under a gradient of temperature conditions (30°C, 25°C, and 20°C) using upflow anaerobic sludge blanket (UASB) reactors. Results demonstrated that the experimental reactor with intermittent biogas injection exhibited significantly superior nitrogen removal efficiency and long-term operational stability compared with the non-biogas control group at each tested temperature. Specifically, the total nitrogen removal efficiency of the biogas-amended reactor remained as high as 74.83% at 20°C, which was markedly higher than that of the control group. Mechanistic investigations revealed that intermittent biogas injection optimized the physicochemical characteristics of Anammox granular sludge, slowed the attenuation of specific Anammox activity (SAA), and enriched the dominant AnAOB genus Candidatus_Kuenenia via three synergistic pathways: continuous inorganic carbon supply from CO dissolution, pH buffering capacity, and shear force regulation. Collectively, these effects significantly enhanced the low-temperature resistance and operational resilience of the Anammox system. This work provides critical mechanistic insights and technical support for the stable operation of Anammox-based processes in low-temperature regions, advancing the practical application of low-carbon nitrogen removal technologies.
Analysis of Spatiotemporal Changes and Driving Forces of Vegetation Coverage in the Upper Reaches of the Hanjiang River Basin Based on Optimal Parameter Geographic Detector Model, China.
Ding Y, Sun J, Zhao H … +2 more , Hou X, Cao D
Water Environ Res · 2026 Jun · PMID 42281476 · Publisher ↗
The upper reaches of the Hanjiang River Basin (HJRB) are a crucial water source hub that connects the water resources between the south and north of China. Quantifying the spatiotemporal patterns and underlying drivers o...
The upper reaches of the Hanjiang River Basin (HJRB) are a crucial water source hub that connects the water resources between the south and north of China. Quantifying the spatiotemporal patterns and underlying drivers of vegetation dynamics in this region is indispensable for formulating targeted ecological management strategies. This study used MOD13Q1 (250 m) remote sensing data from May to September during 2000-2020, and comprehensively applied Theil-Sen + Mann-Kendall and Hurst index methods to analyze the spatiotemporal changes of NDVI, which was verified by stability analysis. When considering the impacts of natural and human driving forces, an innovative optimal parameter geographic detector (OPGD) model was utilized, effectively addressing the modifiable areal unit problem (MAUP) often overlooked by traditional methods, thereby enhancing the rigor of statistical evaluation and the precision of identifying NDVI drivers. It solves the deficiencies of traditional methods in handling spatially heterogeneous data and enhances the reliability of the model. The findings revealed the following: (1) The regional NDVI significantly increased from 2000 to 2020 (slope = 0.0033 a, p < 0.05) and is anticipated to maintain this upward trend going forward. (2) Altitude, surface temperature, slope, and air temperature are the main driving factors for NDVI changes (with q values uniformly surpassing 0.45). (3) The explanatory power of two-factor interactions on NDVI changes substantially exceeded that of single factors. Among these factors, the interaction between surface temperature and slope exerts the greatest influence on NDVI changes (q = 0.7266), and altitude interactions with other factors are dominant. (4) Except for specific combinations, the vast majority of the interactions of two factors have significant differences with NDVI. At the same time, the optimal threshold intervals or types of each factor conducive to vegetation growth have been determined.
Algae-to-Sludge Inoculation Ratio Regulates Organic Matter and Nitrogen Removal in Algal-Bacterial Symbiosis Systems Treating Shrimp Farming Wastewater.
Nguyen TM, Nguyet PN, Long NH … +5 more , Le NA, Anh LH, Hieu NP, Van Tri D, Le Luu T
Water Environ Res · 2026 Jun · PMID 42281342 · Publisher ↗
This study evaluated the influence of algae-to-sludge inoculation ratio on biomass development and pollutant removal in an algal-bacterial symbiotic system (ABSS) treating shrimp farming wastewater. Batch reactors operat...
This study evaluated the influence of algae-to-sludge inoculation ratio on biomass development and pollutant removal in an algal-bacterial symbiotic system (ABSS) treating shrimp farming wastewater. Batch reactors operated at ratios of 1:2-1:6, along with monoculture controls, were assessed for biomass characteristics, organic matter removal, and nitrogen transformation. The 1:3 ratio achieved the most balanced biomass growth (MLSS: +54.9%; MLVSS: +57.8%) and the highest removal efficiencies, reaching 60.5% ± 7.3%, 89.4% ± 2.9%, and 55.2% ± 15.2% for chemical oxygen demand (COD), ammonium (NH -N), and total nitrogen (TN), respectively. Co-culture reactors consistently outperformed monocultures, suggesting the benefits of coupling algal photosynthesis with bacterial metabolism. The results indicate that biomass balance is a key operational factor governing system performance, likely through its influence on oxygen availability, substrate utilization, and internal mass transfer. Optimizing the algae-to-sludge ratio provides a simple and effective strategy to enhance ABSS performance without increasing aeration demand, offering practical implications for sustainable aquaculture wastewater treatment.
Waterjet Injection Technology to Enhance Bioremediation of Chlorinated Solvents Contamination.
Chien SC, Liu JW, Wu PT … +2 more , Lee YH, Wang TP
Water Environ Res · 2026 Jun · PMID 42272321 · Publisher ↗
This 2-year pilot-scale study aimed to remediate chlorinated volatile organic compounds (cVOCs) in a low-permeability aquifer, with trichloroethylene (TCE) and 1,2-dichloroethane (1,2-DCA) as the target contaminants. To...
This 2-year pilot-scale study aimed to remediate chlorinated volatile organic compounds (cVOCs) in a low-permeability aquifer, with trichloroethylene (TCE) and 1,2-dichloroethane (1,2-DCA) as the target contaminants. To overcome the limitations of conventional amendment delivery methods, a high-pressure waterjet injection technique was applied to create fine circular slots within the aquifer, enabling the directional delivery of electron donor substrates and improving their distribution in low-permeability zones. The efficiency of substrate transport and reaction was evaluated using time-lapse cross-hole electrical resistivity tomography (TL-CHERT) and groundwater monitoring data, including total organic carbon (TOC), chloride, and metabolic by-products such as ethene and methane. Prior to injection, the aquifer at the site was under aerobic conditions with low organic carbon content, indicating insufficient electron donor availability and unfavorable conditions for reductive dechlorination. After waterjet injection, geochemical results indicated that reducing conditions were rapidly established, accompanied by the gradual depletion of dissolved electron acceptors. As anaerobic conditions developed, concentrations of TCE and 1,2-DCA decreased to below Taiwan's Groundwater Pollution Control Standards (0.05 mg/L) within 1 month, with no rebound observed during the subsequent monitoring period. In addition, the formation and subsequent transformation of intermediate dechlorination products, along with the detection of ethene and methane, further confirmed the ongoing reductive dechlorination process. Overall, these results demonstrate that waterjet injection is a robust and practical approach for delivering amendments in heterogeneous, low-permeability formations.
Decoupling Dissolution and Biological Kinetics in Polycaprolactone-Based Denitrification: Direct Determination of Yield and Maximum Specific Growth Rate.
Barkhordari D, Mathew J, Haroun B … +4 more , Rehmann L, Murthy S, Wadhawan T, Santoro D
Water Environ Res · 2026 Jun · PMID 42270136 · Full text
Solid-phase denitrification using biodegradable polymers such as polycaprolactone (PCL) is increasingly proposed as a sustainable alternative to conventional soluble carbon dosing. However, reported kinetic and stoichiom...
Solid-phase denitrification using biodegradable polymers such as polycaprolactone (PCL) is increasingly proposed as a sustainable alternative to conventional soluble carbon dosing. However, reported kinetic and stoichiometric parameters for PCL-based systems are often confounded by mass-transfer and dissolution limitations, hindering accurate determination of biological kinetics. In this study, the dissolution step was explicitly decoupled from microbial growth by presolubilizing PCL prior to use, enabling the direct experimental determination of biomass yield (Y) and maximum specific growth rate (μ) under strictly anoxic batch conditions. Methanol was investigated in parallel as a benchmark soluble carbon source. Yield assays conducted over 12 independent replicates produced statistically similar yields of 0.35 ± 0.08 and 0.38 ± 0.08 g COD per g COD for methanol and PCL, respectively, indicating comparable stoichiometric efficiency for biomass synthesis. Dynamic nitrate depletion profiles were resolved through high-frequency batch testing and fitted using SUMO process modeling. The resulting μ values were 1.3 day for methanol and 2.1 day for presolubilized PCL, indicating that when carbon availability is not limited by dissolution, under the tested decoupled batch conditions, PCL-derived substrates can support higher growth rates than conventional methanol. Long-term acclimation tests showed lower net biomass accumulation with PCL, attributable to its slower carbon release rather than to microbial capacity limits. These results provide the first direct determination of true biological kinetic parameters for PCL-based denitrification, independent of polymer hydrolysis effects. The findings demonstrate that the apparent kinetic constraints previously reported for solid PCL systems primarily reflect physicochemical mass-transfer limitations and not biological capacity. This work establishes design-ready kinetic parameters for integrating biodegradable polymers into predictive denitrification models, supporting the rational implementation of biodegradable polymeric carbon sources in sustainable nitrogen removal processes.
A Systematic Comparison of Multiple Models for Depth-Dependent Decay of Hydraulic Conductivity in Salt Lake Areas: A Case Study of Typical Boreholes in the Qaidam Basin.
Chen J, Zhang B, Chen J … +4 more , Dong Q, Li L, Zhang ZY, Han PF
Water Environ Res · 2026 Jun · PMID 42252487 · Publisher ↗
Hydraulic conductivity is an important hydrogeological parameter that characterizes the hydraulic properties of subsurface media, and the pattern of its variation with depth is of great significance for groundwater syste...
Hydraulic conductivity is an important hydrogeological parameter that characterizes the hydraulic properties of subsurface media, and the pattern of its variation with depth is of great significance for groundwater system simulation and resource evaluation. However, the applicability of some existing theoretical and empirical models describing how hydraulic conductivity varies with depth in salt lake areas still lacks systematic validation and evaluation based on measured data. In this study, seven typical boreholes in the West Taijinar Lake area of the Qaidam Basin were selected as the study objects. Several previous representative models describing the decay of hydraulic conductivity with depth, together with a newly proposed model using the geometric square root method, were selected for comparative analysis. The applicability of these models in a salt lake depositional environment was evaluated using the coefficient of determination (R) and root mean square error (RMSE). The results show that hydraulic conductivity in the study area generally exhibits a significant decreasing trend with depth. Different models for the decay of hydraulic conductivity with depth show different levels of applicability among the boreholes in the study area, and each model can reflect the variation characteristics of hydraulic conductivity with depth to a certain extent. Among them, the model using the geometric square root method shows the strongest applicability for all types of boreholes, although it requires the largest number of parameters. The model of Zhang et al. (2026) and the model of Kuang and Jiao (2014) rank next, and both can better describe the characteristic pattern of hydraulic conductivity in the complex salt lake depositional environment, with rapid decline in shallow layers and gradually slower change in deeper layers. The results of this study can provide a reference for the characterization of hydrogeological parameters and groundwater flow simulation in salt lake areas and also provide a scientific basis for the evaluation of deep brine resources in the Qaidam Basin.
Epoxy-Acrylate Functionalized Cellulose Aerogels: Physisorption-Driven Surface Engineering for Enhanced Dye Adsorption in Water Treatment Applications.
Tomo HSS, Mahanani MP, Fajriani FP … +5 more , Jamilah N, Santoso H, Winarto DA, Liza C, Riswoko A
Water Environ Res · 2026 Jun · PMID 42246129 · Publisher ↗
This study introduces a novel interface engineering strategy for high-performance cellulose/poly (vinyl alcohol) (PVA) aerogels derived from coir fiber waste. To address structural fragility, postsynthesis reinforcement...
This study introduces a novel interface engineering strategy for high-performance cellulose/poly (vinyl alcohol) (PVA) aerogels derived from coir fiber waste. To address structural fragility, postsynthesis reinforcement was achieved through conformal liquid epoxy-acrylate infiltration. Quantitative Barrett-Joyner-Halenda (BJH) analysis confirmed the existence of a pore-wall thickening mechanism that preserved the internal mesoporous network (radius: 1.9-2.6 nm) without interstitial blockage. The functionalized scaffold demonstrated significant thermal stabilization, with the maximum degradation temperature (T) shifting from 283°C to 307°C, coupled with superior mechanical resilience and a bulk density of 0.051 g/cm. Methylene blue (MB) adsorption tests achieved 97.3% removal at pH 10, accurately modeled by pseudo-second-order kinetics and the Freundlich isotherm (R = 0.980, RMSE = 1.507, and Χ = 0.884), indicating spontaneous and endothermic multilayer physisorption. Furthermore, regeneration studies established 70% capacity retention over three cycles while maintaining full macroscopic integrity. These findings indicate that strategic resin infiltration provides a robust and sustainable pathway for the development of durable adsorbents for industrial wastewater remediation.
Techno-Economic and Environmental Assessment of Magnesium-Impregnated Rice Husk Biochar for Nutrient Removal: A Scale-Up and Prospective Soil Application Approach.
Lugo-Arias J, Villa-Parejo J, Escorcia G … +3 more , Lugo-Arias E, Vargas S, González-Álvarez J
Water Environ Res · 2026 Jun · PMID 42240580 · Publisher ↗
This study evaluates the techno-economic and environmental performance of a sequential system based on fixed-bed column adsorption using magnesium-impregnated rice husk biochar (RHB-Mg) for nutrient removal from wastewat...
This study evaluates the techno-economic and environmental performance of a sequential system based on fixed-bed column adsorption using magnesium-impregnated rice husk biochar (RHB-Mg) for nutrient removal from wastewater, coupled with a prospective assessment of its reuse as a soil amendment in irrigated rice systems. Scale-up based on laboratory data resulted in a treatment capacity of 4.32 m/day and a biochar requirement of 56.91 kg/day. The system effectively reduced nitrate and phosphate concentrations below regulatory limits under continuous operation, demonstrating high adsorption performance. The techno-economic analysis over a 20-year period revealed that operational costs are primarily driven by magnesium chloride consumption, which strongly influences overall economic feasibility. Life cycle assessment (LCA) identified biochar production as the main environmental hotspot, contributing the highest impacts across multiple categories due to energy demand. Furthermore, literature-supported and LCA-based evidence indicates that the reuse of nutrient-enriched biochar could potentially reduce fertilizer demand (prospective scenario), decrease irrigation requirements, and contribute to a potential climate change benefit through carbon storage, with an estimated reduction of -1.34-kg CO eq per kg of RHB-Mg applied to soil. However, this stage was evaluated as a prospective scenario and was not experimentally validated. Overall, the proposed system demonstrates strong potential within a circular-economy framework; however, process optimization-particularly in reagent consumption and energy integration-is required to enhance large-scale sustainability and economic viability.
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