Environmental Science: Water Research & Technology最新文献

[This corrects the article DOI: 10.1039/D5EW00838G.].

Background: Wastewater-based epidemiology (WBE) enables the population-level surveillance of molecular and chemical targets. Despite the high prevalence of respiratory diseases, there is a lack of sensitive analytical methods for detecting associated medications in complex wastewater matrices. Methods: We developed and validated a liquid chromatography-mass spectrometry (LC-MS)/MS method using multiple reaction monitoring for 10 common respiratory pharmaceuticals. The workflow integrated freeze-drying for preconcentration, online solid-phase extraction for cleanup, and stable isotope-labeled internal standards (SILs) to compensate for matrix effects. Results: Detection and quantification limits ranged from 0.7 to 19 ng L^-1 and 3 to 125 ng L^-1, respectively, with recoveries of 82-194% and precision within 0.14-7.2% relative standard deviation. Matrix effects (64-228%) were effectively corrected using SILs. Application to 12 neighborhood-level wastewater samples detected 9 of the 10 target compounds, with 6 (albuterol, amoxicillin, azithromycin, cetirizine, diphenhydramine, and fexofenadine), detected above their quantification limits. Fexofenadine was the most abundant, reaching 3309 ng L^-1. Conclusion: This robust, low-volume, high-throughput LC-MS/MS method enables the reliable detection of respiratory pharmaceuticals in wastewater, supporting WBE applications for pharmaceutical use surveillance.

Ceramic membranes have emerged as a game-changing solution for oil–water separation, addressing important environmental and industrial concerns related to oily wastewater treatment. Ceramic membranes work by mechanisms such as straining, adsorption, and coalescence, with porosity, pore size distribution, and surface hydrophobicity all having a significant impact on their performance. Materials such as alumina (Al₂O₃), silicon carbide (SiC), and titanium dioxide (TiO₂) have exceptional chemical stability, heat resistance, and fouling resistance, making them suitable for demanding industrial conditions. Applications include industrial wastewater discharge, water recycling, and pre-treatment processes for desalination, demonstrating their versatility. The review assesses membrane performance parameters including flux, rejection rates, and long-term durability, while also evaluating issues such as fouling and high operational expenses. Surface engineering innovations, dynamic filtering modes, and self-cleaning technologies are being investigated as potential techniques to enhance efficiency and sustainability. Ceramic membranes have the potential to transform sustainable water treatment systems by combining advances in material science and engineering, providing long-term, efficient, and environmentally friendly solutions to global water concerns.

The leaching of nitrogen from agricultural fields into rivers substantially impacts the diversity, composition, and function of sediment microbial communities. However, how elevated nitrogen levels affect the assembly processes of these communities and, in turn, influence water quality remains lacking. This study decodes these causal pathways through a microcosm experiment that simulates nitrogen input using urea, focusing on the assembly mechanisms and the subsequent impact of the reassembled community on water quality. The results demonstrated that nitrogen input shifted the bacterial community assembly from stochastic to deterministic dominance (normalized stochasticity ratio <50%), forming a nested structure with a nestedness-resultant dissimilarity index of 0.02 (compared to 0.01 for the control), whereas fungi were less affected. The reassembled dominant bacterial community included anaerobic Bacillota and Bacteroidota. Mantel analysis revealed that Abditibacteriia, Fimbrifmonadia, and Desulfurellia were the core drivers of water quality changes and black-odorous substances. Structural equation modeling indicated that nitrogen input indirectly reduced dissolved oxygen levels (from 7.10 ± 0.01 mg L⁻¹ to 0.65 ± 0.05 mg L⁻¹) and increased chemical oxygen demand (from 4.81 ± 0.00 mg L⁻¹ to 159.45 ± 9.72 mg L⁻¹) and acid-volatile sulfide levels (from 169.22 ± 0.01 mg kg⁻¹ to 363.13 ± 7.30 mg kg⁻¹) by enriching Desulfurellia. Nitrogen input affected ammonium-nitrogen production (from 3.88 ± 0.03 mg L⁻¹ to 98.72 ± 3.93 mg L⁻¹) through direct chemical action and indirect biological action, while nitrate-nitrogen generation (from 1.55 ± 0.05 mg L⁻¹ to 15.35 ± 1.32 mg L⁻¹) was indirectly regulated by enriching Abditibacteriia, enhancing the potential for water self-purification. The findings of the study confirm that the reassembled microbial community driven by nitrogen input further regulated water quality, providing a theoretical basis for aquatic ecosystem restoration.

Water scarcity is an escalating global challenge driven by population growth and resource depletion. Conventional fresh water production methods typically require access to liquid water sources, limiting their applicability in remote or arid regions. Water-from-air technologies offer a potential solution but are often hindered by high energy demands and/or climatological conditions. This study introduces clathrate-based desalination of deliquescent salt solutions as a novel approach for atmospheric water harvesting, with potassium acetate selected as the model salt. Potassium acetate deliquesces at a relative humidity as low as 23.3%, producing a concentrated saline solution (17.8 wt% at 90% RH). By exploiting the clathrate creeping phenomenon, where hydrates grow along surfaces, enabling facilitated phase separation, 84% purification of this brine was achieved. Advanced architectures, further enhancing the crucial clathrate creeping potentially lead to further improvements of the obtained results. This process demonstrates the potential of an energy-efficient alternative to existing water-from-air technologies.

Trace levels of pharmaceuticals in sewage pose persistent environmental risks due to limited degradation in conventional wastewater treatment. This study addresses this by employing coconut shell-derived biochar (CBC) and its iron-modified variant (Fe-CBC) as activators of peroxymonosulfate (PMS) to degrade acetaminophen (ACP) in both aqueous and raw sewage matrices at low concentrations. Under optimized conditions (Fe-CBC: 500 mg L⁻¹; PMS: 400 mg L⁻¹), ACP removal exceeded 99% within 30 min, outperforming peroxydisulfate (PS) activation. Enhanced surface chemistry and iron sites in Fe-CBC substantially promoted reactive oxygen species (ROS) generation, particularly superoxide (O₂˙⁻) and singlet oxygen (¹O₂), which were confirmed via scavenging experiments to be dominant in driving ACP breakdown. The system maintained robust performance across a wide pH range (3–10) and demonstrated resilience against common inorganic ion interferents. Liquid chromatography mass spectroscopy (LC-MS) identification of degradation intermediates enabled the proposal of a mechanistic pathway. Importantly, Fe-CBC exhibited excellent regenerability over multiple reuse cycles, retaining high catalytic efficiency. In real sewage, the Fe-CBC/PMS combination significantly outperformed CBC/PMS in ACP removal and delivered strong biocidal effects, complete inhibition of E. coli, and evident structural damage to rotifers and nematodes after 90 min. Altogether, the Fe-CBC/PMS process shows strong promise as an integrated approach for simultaneous removal of trace pharmaceuticals and microbial contaminants from sewage.

In this work, a novel oxidation process combining nanoscale zero-valent iron (nZVI) and chlorine is reported for the efficient degradation of a model azo dye (CG-HG) in aqueous solutions. The originality of the process lies in the in situ generation of high-valent iron species (Fe(IV)) as the dominant selective oxidants, rather than classical hydroxyl or chlorine radicals. This provides enhanced selectivity and reduced susceptibility to common radical scavengers. Under optimized conditions (100 mg L⁻¹ nZVI, 250 μM chlorine), the system achieved >95% dye removal within 5 minutes, with a synergy index up to 14.43. Radical quenching experiments and mechanistic investigations confirmed Fe(IV) as the primary reactive species. The process remained effective across varying pollutant concentrations and demonstrated long-term durability with over 80% efficiency retained after 10 reuse cycles. The robustness of the system was further evaluated under realistic conditions, showing variable sensitivity to common inorganic ions (Cl⁻, SO₄²⁻, NO₃⁻, NO₂⁻, Br⁻), surfactants, and humic acids. Notably, Fe(IV)'s high reactivity with nitrite and bromide led to complete inhibition, while chloride and nitrate had minor effects. Unexpectedly, sulfate significantly suppressed performance at higher concentrations, likely due to oxygen salting-out, which reduced Fe(II) release. Finally, tests in natural mineral water, river water, treated wastewater effluent, and seawater demonstrated the system's practical relevance. While moderate salt content in mineral water enhanced dye removal, seawater imposed severe inhibition. Despite the strong primary degradation performance, the process achieved a moderate TOC removal of 38%, indicating the persistence of some by-products and the potential need for complementary post-treatments (e.g., biological processes) for full mineralization. These findings underline the importance of matrix composition and support the feasibility of the nZVI/chlorine process as a selective, rapid, and durable oxidation process for pollutant degradation in real water systems, especially, natural mineral water.

The aim of this paper was to examine the growth and mobilization behavior of early-stage biofilms in a pilot scale, controlled PVC drinking water system. An alternative method for biofilm growth used a concentrated solution of microorganisms sourced in tap water to inoculate the pipe system and allowed biofilms to be formed over a 28-day period. Biofilm development was also assisted with nutrient addition and disinfection depletion from the experimental system water. The pipe loop was then flushed to mobilize these biofilms. The growth and mobilization of the biofilms were assessed with molecular and fluorescence microscopy analysis of bulk water samples and removable pipe wall samples. Results showed that: (1) biofilms followed a rapid growth period on the pipe wall between 0 and 14 days, and 21 and 28 days; (2) biofilm growth was apparently halted between 14 and 21 days, likely because of a shift in bacterial community composition; (3) biofilms were observed to preferentially accumulate at the invert pipe position along the full longitudinal direction of the pipe but rapidly decreased for the springline and obvert circumferential positions of the pipe; (4) a flushing flow of 6.5 L s⁻¹ (1.2 Pa) was not able to fully remove the biofilms from the pipe wall; (5) biofilms were observed to form in clusters on the pipe wall which remained fully attached to the pipe wall even after flushing. Biofilms investigated here were likely impacted by the alternative growth method, but their physical structure still resembles biofilms from operational DWDSs. The research findings add to the emerging knowledge concerning the growth and mobilization of biofilms in drinking water systems. In addition, the alternative method to investigate biofilms is highly reproducible and can facilitate future studies in the field.

N-Nitrosodimethylamine (NDMA) is a probable human carcinogen that can be formed in drinking water treatment systems as a byproduct of chloramination and chlorination. Occurrence of NDMA and other N-nitrosamines in the United States has been previously assessed using a variety of techniques, but few studies have been able to distinguish between concentrations above and below suggested screening levels (e.g., 0.7 ng L⁻¹ for NDMA). This study evaluated the presence of NDMA and seven other N-nitrosamines in two drinking water distribution systems in the northeastern United States (n = 42 locations) and assessed factors influencing its occurrence. NDMA was present in 98% of water samples across both systems (MDL 0.15 ng L⁻¹) with higher concentrations in the system utilizing chloramination (0.39–1.32 ng L⁻¹) than the system utilizing chlorination (0.20–0.54 ng L⁻¹). Samples were collected before and after flushing taps, and higher concentrations of NDMA were observed in samples collected prior to flushing, suggesting increased formation due to temporary stagnation. N-Nitrosomorpholine was the only other N-nitrosamine detected in samples taken after tap flushing (5% detection rate; MDL 0.21 ng L⁻¹), though four additional nitrosamines were detected before flushing in at least one sample. Water quality parameters (i.e., chlorine residual, dissolved organic carbon, total dissolved nitrogen, specific UV absorbance, pH, temperature, specific conductance) and other disinfection byproducts (trihalomethanes) were measured to assess correlations with NDMA occurrence, and NDMA concentrations were negatively correlated with residual chlorine in both distribution systems. These observations illustrate the potential prevalence of low-level nitrosamine occurrence in disinfected drinking water and provide a framework for system-specific understanding of NDMA occurrence, which can aid in prioritizing locations where further investigation may be needed to mitigate potential exposure risks.

This study systematically compared four advanced oxidation processes (AOPs) for norfloxacin (NOR) degradation in aquatic systems: O₃, O₃/UV, O₃/H₂O₂, and UV–H₂O₂/O₃. The UV–H₂O₂/O₃ system demonstrated the highest degradation efficiency, achieving 83.85% NOR removal within 1.5 minutes with a reaction rate constant 125.09% higher than O₃ alone. Considering both economic feasibility and efficiency, the O₃/UV system showed superior practical value, exhibiting an 82.56% higher pseudo-first-order reaction rate than standalone O₃ treatment. The optimal operating conditions were determined to be an ozone concentration of 0.5 mg L⁻¹ and UV fluence of 44 mJ cm⁻². Radical scavenging experiments revealed that direct O₃ oxidation contributed 31.47% to overall degradation. The ·OH exposure in the O₃/UV system reached 3 × 10⁻¹⁰ mol L⁻¹ s⁻¹, representing an 8.98-fold increase over ozone treatment alone. LC–MS analysis coupled with DFT calculations identified four primary degradation pathways: piperazine ring cleavage, quinolone core ring-opening, decarboxylation/defluorination, and direct aromatic defluorination. Cytotoxicity assessment using CHO cells confirmed safety with >90% cell viability across all systems. Pilot-scale validation using real water matrices was conducted, achieving 84.21–90.34% NOR removal and significant UV₂₅₄ (52.71–58.36%) and total organic carbon (TOC) (27.47–31.34%) reduction. Background water matrix composition, reactive radical generations, significantly influenced performance, with Yellow River water getting the highest treatment efficiency due to lower dissolved organic carbon and turbidity. This investigation bridges the gap between laboratory research and practical application, providing both mechanistic insights and practical solutions for antibiotic contamination control in aquatic environments.