ACS ES&T water最新文献

This study developed an innovative system coupling iron–carbon microelectrolysis with a deep bed denitrification filter (DBDF) for the advanced treatment of secondary effluent. The key innovation lay in revealing the synergistic pollutant removal mechanisms through microbial community succession and metabolism pathway enhancement. Results showed that the effluent concentrations of total nitrogen, nitrate, and total phosphorus were stabilized below 2.5, 0.55, and 0.25 mg/L, and 41.05% of chemical oxygen demand was removed. Microorganisms in the microelectrolysis column (MEC) and DBDF all varied with the change of reactors height. The dominant genera in the MEC were Dechloromonas, Dechlorosoma, and uncultured_bacterium_f_Rhodocyclaceae, and the abundance of NO₃^– dependent Fe oxidizing Dechloromonas reached 20.15% at sampling point I. Acinetobacter, Hydrogenophaga, uncultured_bacterium_f_Rhodocyclaceae, Flavobacterium, and Thauera were the dominant genera in the DBDF. The pathways of N metabolic, carbohydrate metabolism, and energy metabolism all maintained high abundance in the combined process.

Relatively few published studies have assessed the microbiological or chemical quality of bottled water in the USA. We purchased all single and multipackage bottled water sold in grocery and retail stores in one county in Virginia. 107 samples, across 26 brands, were tested for pH, conductivity, dissolved oxygen, total coliform, E. coli, nitrate, sulfate, free chlorine, total trihalomethanes (THMs, a component of disinfection byproducts), fluoride, and heavy metals. 64.5% (n = 69) of samples were purified water and 35.5% (n = 38) were spring water. Contaminant concentrations were higher overall in spring water samples. Total coliforms and E. coli were not detected in any samples. 1.4% (n = 1) of purified bottled water samples exceeded regulatory standards for THM (80 ppb), and 7.2% (n = 5) and 10.5% (n = 4) of purified and spring samples exceeded 1/2 the THM standard, respectively. No spring water samples exceeded standards for heavy metals, but one purified bottled water sample exceeded the standard for cadmium. We observed considerable within-brand variability in concentrations for a number of parameters including THMs, calcium, silicon, and strontium. This is the first study we are aware of to analyze contaminant variability within bottled water brands. Our results indicate that monitoring and reporting requirements for bottled water should be improved.

Almost all tested bottled water samples complied with regulatory standards; however, a few did not, and we observed considerable within-brand variability for some parameters.

The effluent generated in car and motorcycle wash processes contains several contaminants, including metals, oils, greases, surfactants (MBAS), microorganisms, high chemical oxygen demand (COD), and turbidity. When not properly treated, these compounds can cause severe environmental damage. In this study, the EC process was applied to treat this effluent. A predictive model was obtained using an experimental design methodology. The effects of the area and distance between aluminum electrodes and treatment time on the percentage reduction of COD and MBAS in a real vehicle wash station effluent (VWSE) were evaluated. The process was tested for 30 to 330 min at an electrical potential of 10.0 V. A 3³ full factorial design was used to develop the mathematical model, which was experimentally validated. Under the best-predicted model conditions (1.0 cm electrode spacing, 18.0 cm² area, and 330 min), COD reductions of 90% and MBAS reductions of 97% were achieved. The validated models and optimized parameters support the sizing and design of the electrolytic reactors for VWSE treatment. The 3³ full factorial design with statistical validation provided predictive capability and process optimization, evaluating the efficiency of the EC process and also allowed the prediction of system behavior under different operating conditions.

Electrocoagulation treats car wash effluent with up to 97% pollutant removal, validating a predictive model through experimental design.

With the popularization and application of polymer flooding technology in oilfields, many problems have arisen for the walnut shell filter in service, such as poor regeneration of granular media, contamination of the filter bed, and low efficiency of oil/water separation. A new high-gravity backwashing system, based on the perspective of the “field”, has been established. This system primarily uses Bezier curves for parametric modeling of blade cross sections, and a theoretical mathematical model of the high-gravity backwashing velocity gradient G value in the efficient zone has been developed. Meanwhile, the interparticle collision regulation of the high-gravity backwashing process was simulated using the coupled FLUENT-EDEM method. The simulated velocity gradient G values were obtained for different high-gravity values and are in general agreement with the theoretical G values. The optimal high-gravity value for backwashing was determined through numerical simulation and experimental validation. The surface properties of walnut shell filter media before and after backwashing were analyzed using SEM and XPS methods to provide a reference for subsequent high-gravity backwashing studies. The high-gravity backwashing process breaks through the technical bottleneck of backwashing under a gravity field, which will promote technical iteration and upgrading in oilfields.

Abandoned mines are significant contaminant sources to rivers and lakes, with metal(loid) leaching and acid drainage impacting water quality and ecosystem function. While mine drainage is conventionally assumed to contribute contaminants continuously over decadal time scales, recent findings indicate episodic pulses of metal(loid) export with uncertain drivers. Here, we investigate a former lead–silver-zinc mine (Reiche Zeche, Germany) that drains directly into Elbe River tributaries, identifying spatial and temporal peaks in contaminant release, i.e., “hotspots” of reactivity. Through biogeochemical monitoring and molecular profiling of dissolved organic matter (DOM) and microbial communities, we reveal dynamic contaminant sources. One hotspot exhibited a release pattern controlled by density stratification, in which deeper, isolated layers with iron-oxidizing bacteria intensively accumulated metals and DOM. We demonstrate that specific molecular formulas within DOM are tightly coupled to metals, such that DOM can act as a persistent tracer of hotspot activity while also potentially enhancing metal(loid) complexation, stabilization, and release processes. A broader survey of abandoned mines (n = 28) revealed similar DOM signatures downstream of leaching sites, suggesting similarities in the contaminant release dynamics. These findings provide a framework for novel contaminant monitoring approaches and highlight the need for improved water management strategies at subsurface–surface interfaces in postmining landscapes.

This work provides a unique insight into the hydrological dynamic, biogeochemical functioning, and regional prevalence of contaminant release from (abandoned) subsurface mines.

The degradation of ozone (O₃)-recalcitrant organic micropollutants (OMPs) is limited by the selectivity of O₃ toward electron-rich moieties. This study investigates the dual role of natural organic matter (NOM) in ozonation, focusing on its ability to inhibit or promote hydroxyl radical (HO^•) formation, thereby influencing the degradation of O₃-resistant OMPs. Tannic acid (TA), gallic acid (GA), catechin (CAT), and tryptophan (Trp) were selected as NOM surrogates, representing phenolic, carboxylic, and amine functional groups. Atrazine (ATZ) served as a model OMP to evaluate the effects of NOM moieties, molecular weight, and concentration on degradation kinetics. During an initial phase (<20 s), aromatic, phenolic, and amine groups enhanced HO^• formation, achieving 50% ATZ degradation, with over 85% achieved within 200 s. However, higher NOM concentrations (>5 mg/L) exhibited inhibitory effects due to increased O₃ depletion and radical scavenging. Phenolic moieties strongly enhanced ATZ degradation, with their effect increasing proportionally with concentration, while carboxylic groups, especially GA, scavenged HO^•, resulting in low HO^• yields (0.08–0.12) at 3–10 mg/L. These findings provide critical insights into the role of NOM functional groups in ozonation, advancing the understanding of O₃ demand, OMP fate, and process optimization in water treatment.

The Red River Delta (RRD), Vietnam, like many large river systems worldwide, faces significant pollution due to human activities. Tracing pollution sources, quantifying waste flows, and assessing their distribution across regions remain major challenges. Material Flow Analysis (MFA) is an effective tool to address these issues, providing valuable insights for policymakers and supporting practical mitigation strategies. We employ MFA to assess the potential nitrogen pollution in the RRD estuary, providing an overview of nitrogen sources and pathways and quantifying their relative significance at the provincial level. Our analysis reveals that rice fields and fish ponds are the primary nitrogen sources, accounting for 53–74% and 21–32% of total nitrogen inputs to surface water, respectively. Based on sensitivity analysis, we propose mitigation measures, including a 10% reduction in chemical fertilizer use, improved fishpond drainage at harvest, increasing domestic wastewater collection to 50–70%, and enhancing treatment efficiency for livestock manure to 50%. These measures could reduce total nitrogen loads to the RRD by 13–58%. The accuracy of our simulations is supported by secondary data and field studies. A comparison of the simulated and estimated nitrogen loads suggests substantial nitrogen retention within the delta, estimated at approximately 63%.

The present work focuses on pectin (Pec) encapsulated with Senna obtusifolia leaf biochar (SBC) and cerium metal–organic frameworks (Ce-MOFs) namely, the Pec/SBC/Ce-MOFs composite developed by way of the hydrothermal method. Various techniques, including SEM, TGA, DTA, EDAX, and FT-IR, were used to analyze the physicochemical properties of the Pec/SBC/Ce-MOFs composite. Batch experiments were examined the effect of temperature, coexisting ions, contact time, and pH. The Pec/SBC/Ce-MOFs composite reached a maximum phosphate adsorption capacity of 43.00 mg/g within just 30 min. The adsorption process also affected the pH, and among coanions, sulfate had the most significant effect. Isotherm studies indicated that phosphate adsorption followed a multilayer process, aligning with the Freundlich isotherm model. Kinetic investigations found thatIntraparticle diffusion (IPD) and pseudo-second-order (PSO) models best describe the adsorption behavior. Thermodynamic analysis confirmed that phosphate adsorption on the Pec/SBC/Ce-MOFs composite was a spontaneous and endothermic way. The prepared Pec/SBC/Ce-MOFs composite was effective for up to 5 rounds, and its viability in field circumstances was assessed.

Enteric pathogens Salmonella, Campylobacter, and norovirus are the leading causes of gastroenteritis in the United States. The current study applies wastewater-based epidemiology (WBE) to detect and back-estimate the prevalence of these diseases in the tri-county Detroit area (TCDA), Michigan. Concentrations of Salmonella enterica, Campylobacter jejuni, and norovirus (GI and GII) were monitored by ddPCR between January and December 2024 for norovirus and between July and December 2024 for S. enterica and C. jejuni. Average norovirus concentrations peaked during winter and spring months (1.03 × 10⁵ genome copies (gc)/L) and were higher than S. enterica (1.71 × 10⁴ gc/L) and C. jejuni (7.39 × 10² gc/L) concentrations, which peaked primarily during summer months. Based on measurements in wastewater samples, back-estimation of clinical cases revealed that these enteric pathogens are likely underreported in the TCDA when benchmarked against the clinically reported cases. This study highlights the importance of using WBE to track and estimate enteric disease cases, especially for underreported ones. Moreover, we proposed an improved back-estimation model of S. enterica and C. jejuni, incorporating an adjustment factor β to estimate the rate of bacteria’s prevalence in animals and/or animal-derived products. Furthermore, this study demonstrates disparities in the population’s incidence of these enteric pathogens.

This paper describes one of the first case estimations of norovirus, Salmonella, and Campylobacter based on wastewater surveillance. A back-estimation formula was optimized by incorporating a parameter estimating the prevalence for bacteria in animals and/or animal-derived products.

Coupling nitrite- and nitrate-dependent anaerobic methane oxidation (n-DAMO) with anammox processes enables efficient biological nitrogen removal from wastewaters. However, the inherently slow growth and low activity of n-DAMO microorganisms have hindered their broader applications. Here, we investigated the impact of the exogenous quorum sensing signaling molecule dose on the performance of a lab-scale membrane biofilm reactor (MBfR) integrating n-DAMO and anammox. Long-term operation (∼380 days) demonstrated that the dosage of C6-HSL (N-hexanoyl-l-homoserine lactone, 0.2 μM) enhanced the total nitrogen removal rate of MBfR by 59.0%. In situ batch tests showed that the nitrate removal rate of n-DAMO archaea (Candidatus Methanoperedens) and the nitrite removal rate of anammox bacteria (Candidatus Brocadia) increased by 65.6 and 48.5%, respectively, while the nitrite removal rate of n-DAMO bacteria (Candidatus Methylomirabilis) exhibited a modest increase of 15.4%. qPCR and reverse transcription qPCR confirmed that C6-HSL promoted both growth and specific activity of n-DAMO archaea and anammox bacteria, while it had only manorial effects on n-DAMO bacteria. C6-HSL gradually accumulated in the biofilm and was sensed by these nitrogen-converting microorganisms, triggering gene regulatory responses associated with growth and metabolism. Notably, once the biofilm reached a threshold signaling molecule level, additional C6-HSL dosing became unnecessary. The findings reveal a quorum-sensing-mediated strategy to stimulate key microbial populations in n-DAMO–anammox systems, offering a practical approach for accelerating reactor start-up and intensifying its nitrogen removal capacity.