ACS ES&T engineering最新文献

The practical application of nanoscale catalysts in water treatment is hindered by challenges such as inefficient solid–liquid separation and aggregation-induced deactivation, while simultaneously the oxidation performance of peracetic acid (PAA) in complex wastewater matrices remains underexplored. Herein, we developed a fixed-bed continuous-flow reactor system utilizing millimeter-scale chitosan beads embedded with in situ synthesized cobalt–manganese spinel (CMO@CS). The beads exhibited enhanced catalytic activity (90.1% pollutant removal vs 66.1% for powdered CMO) and structural stability, effectively overcoming engineering bottlenecks of nanoparticle recovery and aggregation. The CMO@CS/PAA system achieved 85.6% removal of over 200 antibiotics, as confirmed by ultrahigh-resolution mass spectrometry (UHRMS), while simultaneously increasing the effluent C/N ratio through controlled carbon supplementation, thereby optimizing compatibility with downstream biological processes. UHRMS and three-dimensional fluorescence spectroscopy indicated that the system achieved a significant reduction in the dissolved organic matter molecular weight, effectively removing or converting macromolecules into small-molecule intermediates. Metagenomic analysis revealed a substantial 46% reduction in top 30 antibiotics resistance genes (ARGs) abundance, demonstrating the system’s capacity to mitigate ecological risks associated with horizontal gene transfer. This work establishes a scalable advanced oxidation process paradigm integrating pollutant elimination, microbial community regulation, and ARGs suppression, providing critical insights into the sustainable management of livestock wastewater.

Selective catalytic reduction of NO_x by ammonia under the exposure of alkaline and heavy metals in fly ash still remains a major challenge for NO_x elimination among air pollution control. Herein, self-protective NO_x reduction catalysts with remarkable alkaline and heavy metal resistance are originally designed by Ce and Cu dual active metal cations coexchanging attapulgite clays. It is revealed that the inherent Si–OH sites among attapulgite and partially exchanged Cu species effectively captured alkaline and heavy metal cation poisons through coordinate bonding or ion exchanging to protect the active components from being deactivated. Ultimately, highly efficient NO_x reduction for stationary source flue gas catalytic purification is realized via the ingenious design of dual metal exchanged clay catalysts that own self-protective capacity to resist alkaline and heavy metal poisoning. This strategy paves the way for the development of low-temperature and high-efficiency denitrification catalysts with alkaline and heavy metal resistance for stationary source flue gas purification.

Microalgae, particularly Chlorella vulgaris (CV), have gained increasing attention for their role in bioremediation and carbon sequestration due to their high photosynthetic efficiency, rapid biomass production, and ability to mitigate environmental contaminants. This study investigates the potential of an engineered nanoenabled microalgal system to enhance the simultaneous degradation of 2-nitroaniline (2-NA), a persistent nitroaromatic pollutant, and carbon sequestration under the influence of titanium dioxide nanoparticles (TiO₂ NPs). The experimental approach assessed the effects of TiO₂ NPs on CV growth kinetics, photosynthetic pigment synthesis, and CO₂ fixation rates while analyzing the degradation efficiency of 2-NA. Results revealed that 20 mg L^–1 TiO₂ NPs optimized algal growth and photosynthetic activity, leading to a 37.4% increase in biomass productivity and enhanced CO₂ sequestration rates compared to control. Extensive characterization including Raman and Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) confirmed TiO₂ NP interactions with algal cellular components, demonstrating maintained structural integrity and biocompatibility. However, coexposure to 2-NA induced oxidative stress, evidenced by significant upregulation of catalase (CAT) and superoxide dismutase (SOD) activities, indicating a defensive response. The TiO₂-integrated CV system demonstrated a 59.8% degradation efficiency of 2-NA at 10 mg L^–1, surpassing biological degradation alone (39%). These findings underscore the dual benefits of integrating nanotechnology with microalgal systems for environmental remediation, offering a circular bioeconomy approach that couples wastewater treatment with carbon capture.

Assessing the risks associated with antibiotic resistance genes (ARGs) in the environment remains challenging due to limited understanding of their distribution and transmission across various media, including wastewater, air, and biosolids. This study addresses this gap by systematically collecting samples from diverse environmental sources and investigating the dynamics of ARG transmission in wastewater treatment plants (WWTPs). A low-cost 3D-printed air sampler was developed using off-the-shelf components and evaluated alongside a commercial active air sampler under identical conditions. The custom sampler was equipped with interchangeable filters, including glass fiber and PVDF membranes, and showed comparable or better performance in terms of ARG detection. While only single 24-h sampling events were conducted per sampler, differences in ARG yield, microbial diversity, and assembly metrics were observed. Using metagenomic sequencing, air samples from locations near effluent discharge points and within biosolids processing areas, alongside wastewater samples, were analyzed. Genomic predictions and homology analyses revealed that ARGs are widely distributed across environmental media, with significant overlap between air and water samples. ARG abundance was higher in the biosolids processing area than at the effluent discharge point. This study introduces a cost-effective monitoring tool for airborne ARGs and provides novel insights into their environmental distribution and potential transmission in WWTPs, informing future risk assessment strategies.

H₂S reforming with CH₄ (H₂SMR) provides a viable approach for the elimination of hazardous H₂S and the direct utilization of sour natural gas, efficiently producing CO_x-free H₂ while simultaneously yielding high-value-added sulfur chemicals. Herein, MoS₂ catalysts enriched with edge sites and sulfur vacancy defects were fabricated via a cost-effective one-step solvothermal synthesis method and examined for the H₂SMR reaction. MoS₂ synthesized using ethylene glycol (EG) solvent (MoS₂-EG) presented oxygen doping and featured fewer layers and a larger interlayer spacing, thus possessing abundant active edge sites and sulfur vacancy defects. Consequently, MoS₂-EG demonstrated exceptional hydrogen production efficiency and stability, achieving a hydrogen yield of 8.5 mmol/(g min) at 900 °C and a H₂S/CH₄ molar ratio of 3. The abundant defects and edge sites in MoS₂-EG contributed to the facile H₂S activation to preferentially form reactive sulfur species for C–H bond activation, which is responsible for the superior H₂SMR activity. This study significantly advances the development of high-efficiency, scalable catalysts for H₂SMR, presenting a transformative approach to utilizing sour natural gas as a resource while addressing environmental challenges.

Microplastics (MPs) produced by human activities can enter the environment through wastewater systems. A significant quantity of MPs still reaches the environment via wastewater treatment plant (WWTP) effluent because the techniques commonly used in WWTPs are not effective at removing MPs, especially smaller particles. To address this, an electrosorption (ES) method was developed in this study to separate MPs (3–5 μm polyethylene particles) from water using graphite felt electrodes. Electrosorption experiments were conducted using a static water cell and a flow-through cell to examine the influence of hydrodynamic forces. Increasing the voltage (up to 12 V) enhanced electrostatic attraction, accelerating removal. Higher flow rates improved MP transport to the electrode, boosting the efficiency. The highest removal (96.9%) occurred at 80 mL/min, 12 V, and 20 mM KNO₃ after 150 min. By analyzing the influence of various parameters on MP removal efficiency and exploring the underlying mechanisms through DLVO theory, this study establishes a foundation for future advancements in ES for MP removal. Future studies could focus on investigating the removal of MPs using ES in more complex real-world environments.

To achieve highly efficient and energy-saving wastewater treatment, a novel process involving a pre-anaerobic/anoxic/aerobic nitrification sequencing batch reactor (pre-A₂NSBR) was developed herein. Further, this process was used to treat mainstream wastewater, and the functional microorganisms in the process were regulated. The results showed that the dual sludge denitrification and phosphorus removal system achieved simultaneous nitrogen and phosphorus removal, demonstrating a good treatment effect. After 300 days of operation, the system achieved chemical oxygen demand, PO₄^3–-P, NH₄⁺-N, and total inorganic nitrogen removal rates of 85.3%, 91.2%, 99.2%, and 70.5%, respectively, resulting in average effluent concentrations of 29.9, 0.7, 0.5, and 12.4 mg·L^–1, respectively. Microbial analysis showed that the main functional microorganisms of the nitrification sequencing batch reactor (NSBR) were Nitrosomonas and Nitrospira, with relative abundances of 13.6% and 15.7%, respectively. The main functional microorganisms of the anaerobic/anoxic/oxic sequencing batch reactor (A₂SBR) were Dechloromonas, Candidatus Accumulibacter, and Thauera, with relative abundances of 21.8%, 1.8%, and 6.2%, respectively. The proportion of the nitrification-related enzyme nxrA and the phosphorus-related enzyme ppk1 increased significantly, which was the main reason for the good nitrogen and phosphorus removal efficiency of the pre-A₂NSBR system. The above-mentioned results demonstrate that the novel pre-A₂NSBR process is a promising technique for energy-efficient wastewater treatment.

Drinking water distribution system (DWDS) necessitates sustainable, durable, and nonpolluting materials for enhanced water quality of the end-users. Stainless steel (SS) is gaining momentum in DWDS, particularly in end-point distribution facilities such as secondary water storage tanks, pumps, and household water pipes due to its high chemical stability and robust mechanical strength. However, SS’s susceptibility to corrosion in given defect areas is of great concern, and there is a lack of fundamental insight on SS corrosion from an interdisciplinary perspective of materials science and environmental science. Herein, the SS corrosion in the DWDS environment is critically assessed, encompassing the basic science of SS corrosion occurrence, its cascading influence on water quality, and anticorrosion strategies. Electrochemical corrosion mechanisms of SS corrosion are specifically differentiated, particularly those initiated at given SS defects, including welding points, grain boundaries, and areas with tensile stress. It is shown that SS corrosion influences water quality by destroying the Cr-rich passive film and releasing Cr, Fe, and other heavy metals from the corrosion scale. The critical factors influencing SS corrosion are subsequently identified, namely, SS elemental composition, SS manufacturing process (e.g., heat-affected zone, stress concentration), and water condition in DWDS (e.g., chlorine, oxygen, sulfate, hydraulic shock, pH). Corresponding strategies are elucidated to facilitate the anticorrosion resistance of SS and improve the water quality, including SS alloying enhancement, SS dispersion strengthening, SS surface treatment/modification, and tuning water condition in DWDS. Overall, this review highlights the importance of controlling SS corrosion, which could provide guidance on the rational design and utilization of SS in DWDS to enhance the ultimate water quality of the end-users and the overall resilience of the DWDS.

High-salinity wastewater contains a high concentration of sulfate (SO₄^2–), posing environmental risks while offering potential for resource recovery. This study developed an electromicrobial hybrid system to achieve simultaneous SO₄^2– removal and elemental sulfur (S⁰) recovery by integrating electrolytic hydrogen-mediated microbial sulfate reduction, H₂S stripping, and off-field electrochemical oxidation. Sulfate reduction occurred in the cathode of the electrolytic-hydrogen-fed reactor, where the generated sulfide was stripped as H₂S into an off-field oxidation unit using a FeCN₆^3–/FeCN₆^4– redox mediator. FeCN₆^3– oxidized H₂S to S⁰, while FeCN₆^4– was regenerated to FeCN₆^3– at the anode. The reactor performance was enhanced by introducing PU@RGO@MnO₂ carriers, with the optimal SO₄^2– removal current identified as 300 mA (6.7 A m^–2). SO₄^2– removal and S⁰ recovery performance was tested under this condition. H₂S stripping coupled with sulfate reduction and off-field sulfide oxidation eliminated the inhibition of high concentration sulfide on sulfate-reducing bacteria, achieving 100% H₂S-to-S⁰ conversion. Therefore, the system achieved an efficient SO₄^2– removal rate of 464.3 ± 7.1 mg of SO₄^2–-S L^–1 d^–1 and a S⁰ production rate of 450.6 ± 8.6 mg of S⁰-S L^–1 d^–1 (SO₄^2– removal efficiency = 92.6 ± 1.3%; S⁰ recovery efficiency = 89.8 ± 1.6%), with a remarkable electrical energy efficiency of 62.5 ± 1.9% and an energy consumption of 20 kWh kg S^0–1. The recovered S⁰ exhibited high purity (99.15%) and could be efficiently separated via gravity settling. The recovered S⁰ exhibited an electrochemical performance comparable to that of commercial S⁰ in the lithium–sulfur battery. This study provides a sustainable approach for wastewater treatment and sulfur recovery, bridging environmental remediation with energy storage application.

Ammonia oxidation plays a pivotal role in biological nitrogen removal from toxic petrochemical wastewater, but its microbial stability under prolonged toxic stress remains poorly understood. This study employed a membrane bioreactor with a gradient dilution approach to treat real petrochemical wastewater, demonstrating that gradual acclimation to toxicity enabled sustained ammonia removal at 0.26 ± 0.02 kg of N·m^–3·d^–1. Progressive dilution selectively enriched the Nitrosomonas and amo genes. However, exposure to low-diluted wastewater triggered a 68.9% reduction in ex-situ ammonia oxidation activity. Notably, Comammox Nitrospira exhibited ecological resilience under high-stress conditions, with its amoA gene abundance increasing 7.6-fold (to 1.3 × 10⁸ copies gVSS^–1) and network centrality surpassing most Nitrosomonas species. Concurrently, Nitrospira maintained a stable nxrB gene abundance and harbored genes for toxic compound degradation, enhancing their ecological versatility. As a genus member, Comammox Nitrospira might leverage these adaptive traits to gain a competitive edge in high-stress environments. These findings reveal toxicity-dependent niche partitioning between Nitrosomonas and Comammox and emphasize the need to integrate microbial community dynamics into early prediction of performance shifts for optimizing industrial wastewater treatment under fluctuating toxic loads.