ACS ES&T engineering最新文献

Drinking water distribution systems contain chlorine and metals that can promote antibiotic resistance. Corrosion inhibitors are required to prevent the leaching of metals into drinking water. While utilities have a choice of which corrosion inhibitor they employ, the impact of corrosion inhibitor type when combined with chlorine on antibiotic resistance is unknown. The objective of this research was to understand the impacts of zinc orthophosphate, sodium orthophosphate, and sodium silicate, three commonly used corrosion inhibitors, on antibiotic resistance when mixed with chlorine. Culture-based plating was paired with metagenomics analysis on lab-scale microcosms. The addition of all three corrosion inhibitors resulted in a significantly higher absolute abundance of antibiotic resistant bacteria with resistance to rifampicin, sulfamethoxazole, and vancomycin, while the addition of phosphate-based inhibitors (sodium orthophosphate and zinc orthophosphate) at 1 mg/L also resulted in significantly higher absolute abundance of ampicillin-resistant bacteria. Exposure to all three types of corrosion inhibitors and free chlorine led to significantly higher abundances of ARGs conferring resistance to the target antibiotics used in the phenotypic assessment. Observed changes in the resistomes compared to the controls were influenced by an enrichment in ARGs responsible for multidrug resistance and resistance to peptide antibiotics. In general, most of the ARGs were associated with chromosomes, but a significant increase in the number of ARGs colocated with plasmid and integron sequences was observed. In contrast, the abundance of viral-associated ARGs decreased in the treatments compared to the controls. These results highlight the importance of corrosion inhibitor selection and the potential impacts on antibiotic resistance in potable water systems.

Microelectronics manufacturing generates substantial wastewater, containing toxic contaminants. Although the reverse osmosis (RO) membrane is a promising treatment technology, its suboptimal water permeance and limited rejection of low-molecular weight (MW) organic contaminants restrict its practical application. Herein, we present a simple approach for developing RO membranes fabricated via interfacial polymerization with boric acid as an additive, which enhances the water permeance and superior removal efficiency for low-MW contaminants in microelectronic wastewater. The boric acid-modified RO membranes exhibited a remarkable increase in water permeance up to ∼4.2 L/(m²·h·bar), a 3-fold enhancement compared to the pristine membrane thanks to the formation of smoother and thinner polyamide (PA) layers. Meanwhile, owing to the denser PA layers, the modified membranes reached a 2–18% higher removal efficiency for common low-MW contaminants in microelectronic wastewater compared to the commercial membranes. The penetration of organic substances through the modified membranes in real wastewater was decreased by 50% with respect to that of the commercial membranes. The hydrogen bonding interaction between the amine monomer and boric acid, along with the buffering effect of boric acid, collectively promoted the formation of denser and thinner PA layers. This study offers valuable insights into the development of RO membranes for the recovery of microelectronic wastewater or analogous effluents containing low-MW contaminants from the perspective of interfacial polymerization regulation.

The pollution of antibiotics to the environment has attracted more and more attention from society. Therefore, it is necessary to develop effective and practical methods to degrade antibiotics. In this study, micronano bubbles (MNBs) were employed as mechanical stress to induce piezoelectric potential in barium titanate/polyvinylidene fluoride (BTO/PVDF) composite membranes, enhancing piezo-photocatalytic degradation of tetracycline (TC). Under the synergistic piezo-photocatalytic effects, the system achieved 93% TC removal within 1.5 h, with a quasi-first-order reaction rate constant (k) of 0.022 min⁻¹. This value is 5.9-fold and 2-fold higher than those of standalone MNBs and BTO/PVDF systems, respectively. Finite element simulation analysis determined the influence of MNBs on the induced potential and piezoelectric field distribution in the composite membrane, indicating that the MNBs’ environment met the pressure conditions for BTO/PVDF to generate induced potential. Remarkably, changes in photocurrent and impedance data showed that MNBs not only enhanced light absorption but also reduced membrane impedance, improving carrier separation efficiency. Electron paramagnetic resonance (EPR) and free radical scavenging results showed that the contribution of hydroxyl radicals (•OH) in the degradation process was more significant. Therefore, the piezoelectric effect induced by MNBs is expected to provide a new idea for the treatment of antibiotic wastewater.

It is critical to balance the effective inactivation of microorganisms with the formation of disinfection byproducts and associated processing costs during ozone disinfection in water reuse. Through systematic ozone disinfection experiments, the specific ozone dose, ultraviolet (UV) absorbance at 254 nm, total fluorescence, and characteristic fluorescence peak A were identified as surrogate parameters for predicting the inactivation efficacy of indigenous fecal coliforms, heterotrophic plate count, and Pseudomonas aeruginosa by ozone in four different reclaimed waters. Corresponding empirical logistic regression models were established to correlate surrogate abatement with microbial inactivation (R² = 0.743–0.970) within a high ozone dosage range (0–8 mg/L). A spectral surrogate-based monitoring system for real-time surveillance and online control of ozone disinfection was designed and further validated through laboratory experiments, demonstrating that fluorescence peak intensities at the characteristic excitation wavelengths of 240, 280, or 335 nm could predict microbial inactivation properly by logistic regression models (R² = 0.793–0.991) using portable UV light sources and miniaturized fluorescence signal detection instruments. Taken together, this study provides a viable approach for reliable economical and quick-response ozone disinfection in reclaimed water.

Colistin, also known as polymyxin E, is an antimicrobial agent effective against various Gram-negative bacteria. The broad dissemination of colistin resistance over the past decade is concerning, given its importance as a last resort for treating carbapenem-resistant Enterobacteriaceae infections. Mobilized colistin resistance (mcr) genes were first discovered in 2015, and now 10 genes (mcr-1–10) have been identified worldwide. The present work aims to examine the response of mcr genes to increasing colistin selective pressure and associated shifts in the microbial community in anaerobic membrane bioreactors (AnMBRs) treated with low-strength wastewater. Colistin was added at incremental concentrations of 10, 50, and 100 μg/L for 10 d each to a bench-scale AnMBR in comparison to a control AnMBR without colistin addition. Quantification of mcr-1–10 using novel duplex-droplet digital PCR assays revealed the positive detection of mcr-1, mcr-2, mcr-3, mcr-4, mcr-5, mcr-6, mcr-9, and mcr-10 in biomass and membrane biofilm samples. While the abundance of mcr genes in the biomass and biofilm of AnMBR was generally unaffected by influent colistin concentration, all mcr genes were below the detection limit in the effluent. However, DNA- and RNA-based amplicon sequencing indicated a distinct shift in microbial community structure of the biomass, biofilm, and effluent upon exposure to colistin. Relative abundance and activity of Rectinema spp., Sulfurospirillium spp., Pseudomonas spp., and Dechloromonas spp. were significantly affected by colistin exposure.

Colloidal activated carbon (CAC) is a promising technology for the in situ remediation of groundwater impacted by perfluoroalkyl and polyfluoroalkyl substances (PFAS). The long-term performance of an engineered CAC barrier will depend, in part, on the emplacement and remobilization of CAC particles within aquifer media. We here explored the influence of calcium ions (Ca²⁺) and Suwanee River natural organic matter (SRNOM) on CAC deposition and remobilization within saturated sand columns. Our results showed that the presence of Ca²⁺ (e.g., >5 mM) under high ionic strength conditions (100 mM) enhanced CAC deposition and subsequently reduced its remobilization upon the introduction of a low ionic strength solution (i.e., DI water). A combination of cation bridging and electrostatic screening, driven by Ca²⁺, contributed to the increased retention of CAC in the sand column. In contrast, when SRNOM was present at concentrations above 5 mg/L, CAC exhibited reduced deposition under high ionic strength conditions (100 mM), followed by markedly enhanced remobilization upon flushing with a low ionic strength solution. This behavior is primarily driven by increased electrosteric repulsion at the CAC–sand interface when the sand surfaces are coated by NOM. Atomic force microscopy (AFM) force measurements showed that under the same ionic strength, Ca²⁺ increased the work of adhesion between CAC and silica surfaces, whereas NOM decreased it. Our work underscores the critical influence of both the presence and concentration of Ca²⁺ and NOM on the deposition and remobilization behaviors of CAC, providing valuable insights into the engineering design and practical implementation of in situ CAC sorptive barriers for effective PFAS remediation.

The inhibition of nitrite-oxidizing bacteria (NOB) has long been regarded as a major challenge for achieving stable partial nitrification (PN) process. However, the persistence of NOB, even under inhibitory conditions, suggests its potential functional importance in PN systems. This study comparatively analyzed the response of PN systems from reactor performance to gene expression, under ammonium and nitrite shock loadings to elucidate the hidden role of NOB. Results demonstrated that PN systems exhibited greater resistance to nitrite shock, maintaining a 58.2% ammonium removal efficiency even at a nitrite concentration of 300 mg L^–1. But this resistance impaired when NOB activity was suppressed. Unlike elevated ammonium, high nitrite concentrations stimulated the expression of amo, hao, nirSK, norBC, and nosZ genes, enhanced ammonia monooxygenase and nitrite reductase activities, and improved the overall activity of ammonia-oxidizing bacteria (AOB). Isotopic analysis using ¹⁵N-labeled nitrite revealed the production of ³⁰N and ²⁹N, indicating that nitrite reduction mitigated nitrite toxicity to AOB. Notably, NO was identified as a potential signaling molecular mediating synergistic interactions between AOB and NOB, contributing to support system stability. Overall, this study provides unique insights into the functional role of NOB in improving the resilience and stability of PN systems under stress conditions.

High-valent metal oxidants (HVMOs) have attracted considerable attention in advanced oxidation processes (AOPs) due to their high selectivity for oxidizing organic pollutants. However, the pursuit of green and efficient activators, together with the clarification of external factors affecting HVMO performance, remains a major challenge in practical applications. In this review, we present a comprehensive overview of the chemical properties of HVMOs, with a particular emphasis on their oxidation characteristics, focusing on permanganate (MnO₄^–), ferrate (FeO₄^–), dichromate (Cr₂O₇^2–). We further analyze energy changes and redox potential variations during the oxidation process. Recent advances in the activation of HVMOs by metal-free carbon materials are summarized, and the potential effects of common coexisting substances in environmental matrices, such as H⁺, OH^–, inorganic anions, metal ions, and natural organic matter (NOM), are critically examined. Moreover, potential risks associated with residual HVMOs after organic pollutant oxidation are discussed, along with relevant separation and purification strategies. This review aims to deepen the understanding of HVMOs in environmental catalysis, explore their potential for resource recovery, and provide perspectives on future research directions and practical applications.

Water reclamation facilities contribute to the emission of greenhouse gases during the treatment of wet waste and following the release of the treated water effluent in receiving water bodies due to the high concentration of greenhouse gas precursors dissolved in the effluent. Here, an electrochemical cell was used to capture inorganic carbon dissolved in the treated liquid effluent discharged from four wastewater treatment plants. A pH gradient was induced in the effluent flowing in the electrochemical cell, facilitating the transformation of bicarbonate ions into carbon dioxide and solid metal carbonates that were removed from solution with overall efficiencies exceeding 57 ± 2% (96 ± 0.5% as gaseous CO₂ at the anode and 19 ± 4% as CaCO₃ at the cathode). Understanding how solution chemistry and electrochemical parameters dictated the performance of CO₂ capture allowed to optimize operational parameters and reactor architecture to minimize energy demand to 3.4 kWh/kg CO₂ with real treated effluents, a value that makes this approach competitive with current technologies for commercial CO₂ capture from the ocean or the atmosphere. Finally, performance stability was investigated by operating the cell for 55 h, quantifying carbon capture efficiency and energy demand over time. This study demonstrates for the first time that electrochemical CO₂ capture from treated water effluents provides an end-of-the-pipe decarbonization approach that, when implemented in conjunction with the use of renewable electricity, can accelerate the decarbonization of the water infrastructure and reduce the emission of greenhouse gases in the environment.

Recent advances in the electric vehicle technology and industry caused a substantial growth of the LIB market, which increased the demand for the key resources such as lithium, nickel, and cobalt. There have been significant efforts to recycle spent LIB electrodes in order to secure the supply chains of the resources and make LIB production and utilization cycles more sustainable. In this study, we developed processes for the selective recovery of lithium and nickel from the black mass produced from spent LIBs. By using HCl solution at the optimized conditions, leaching of lithium and nickel from the black mass could be performed with high selectivity over other metallic species. A flow-type integrated electrochemical system was prepared by using lithium nickel manganese oxide (LiNi_0.5Mn_1.5O₄) and titanium foil electrodes for lithium electrosorption and nickel electrodeposition, respectively. By cyclic operation of the electrochemical process, both lithium and nickel could be recovered effectively with reasonable energetics and stability, corroborating the capability of the integrated system.