ACS ES&T water最新文献

Iron sequestration by phosphate was examined from the perspective of mechanisms, water chemistry impacts, and inherent limitations. Phosphates slowed Fe²⁺ oxidation above about pH 7–8, but a combination of ferric complexation and colloid stabilization caused iron to remain invisible. Orthophosphate was a weak sequestrant, but at relatively low pH and hardness, it could be effective and is not thought to worsen corrosion control. Increased phosphate chain length, phosphate concentration, and silica concentration caused more effective sequestration, whereas calcium, magnesium, and increased pH could make it ineffective. When polyphosphate was dosed, the percentage of iron less than 10K apparent size decreased linearly by about 10% for every 100 mg/L increase in CaCO₃. Furthermore, up to 4× more tripolyphosphate was needed to effectively sequester iron at pH 9 versus pH 7. Contrary to some published guidelines, iron at concentrations above 1 mg/L could sometimes be sequestered effectively with exponentially increasing doses of polyphosphate, but at some point, higher chemical costs or precipitation (e.g., calcium phosphate or iron phosphate) became limiting.

The mechanisms, water chemistry effects, and limitations of iron sequestration are systematically investigated.

Produced water (PW) from energy extraction operations in the Permian basin is managed using a range of treatment, recycle, and disposal options. There is interest in the research community to evaluate the beneficial use of treated PW outside the oil field. The present work provides a detailed chemical characterization of the PW that has undergone treatment to remove salts, organics, and other constituents. The treated PW was further evaluated using a range of whole effluent toxicity test species, such as fish and invertebrates, terrestrial species, and in vitro bioassays. Toxicity modeling was used to integrate analysis of the chemical and toxicology data to estimate the relative contribution of different chemical constituents in the treated PW. The results indicate that ammonia is the largest contributor to the observed aquatic toxicity in the treated PW and that other constituent classes like hydrocarbons and metals are minor contributors to the observed toxicity to aquatic organisms. There was no observed cytotoxicity tested with extracts of the organic chemicals from the treated PW, which is consistent with the aquatic toxicity tests, and the terrestrial species were less sensitive than the aquatic species. These results can inform management options for the treated PW including potential end-use considerations.

We demonstrate that chemical concentration data can be used to interpret whole effluent toxicity data to evaluate safety of treated produced water.

This study developed a novel layered metal oxide–covalent organic framework (LMO–COF) membrane for the simultaneous removal of pharmaceutical micropollutants and nanoplastics from wastewater. The membrane was integrated with peroxymonosulfate (PMS) as an oxidant, achieving optimal performance at 20% COF (0.025 M) relative to the total LMO content. Under these conditions, complete removal of ranitidine (0.1 mM PMS) and 100% rejection of the nanoplastics were achieved. The membrane delivered a high water flux of 1300 L/m²/h/bar, ensuring efficient micropollutant mineralization even at low PMS levels. Stability tests confirmed consistent performance over 10 operational cycles with a 96% flux recovery ratio. Removal efficiency was sustained across a wide pH range (3–11) and in the presence of various anions, while cobalt leaching remained minimal (0.03–0.1 μg/L). These findings highlight the membrane’s robustness, durability, and potential for large-scale application in wastewater treatment plants.

The interaction of five systematically structured homologous phosphonated linear amino acids (PLAAs, HOOC-(CH₂)_n-N-(PO₃H₂)₂), glycine (PLAA-C2, n = 1), β-alanine (PLAA-C3, n = 2), γ-aminobutyric acid (PLAA-C4, n = 3), 5-aminovaleric acid (PLAA-C5, n = 4), and ε-aminocaproic acid (PLAA-C6, n = 5), with carbon steel in an aqueous solution is explored. The inhibition efficiency of the PLAAs was investigated through electrochemical impedance spectroscopy, potentiodynamic polarization, and gravimetric studies. Inhibitor adsorption onto the carbon steel surface and its impact on inhibitory performance were further studied through Density Functional Theory simulations. The inhibitory performance increased with the increase in the alkyl chain length due to enhanced orbital overlap and stronger binding interactions between the carbon steel surface and PLAAs. PLAA-C6 exhibited the best performance, significantly inhibiting corrosion at concentrations as low as 10 ppm, reaching the optimum performance at 50 ppm. The synergistic effects of two selected inhibitors (PLAA-C4 and PLAA-C6) with Zn²⁺ ions were investigated, showing substantially enhanced corrosion protection. This was ascribed to the formation of Zn-PLAA protective films on the carbon steel surface.

This study investigates the influence of nitrate-based electrolytes─specifically LiNO₃, NaNO₃, and KNO₃─on the performance, reproducibility, and operational efficiency of Photoelectrochemical Oxygen Demand (PeCOD) devices. A systematic evaluation was conducted across three operational concentration ranges to identify the interplay between ionic conductivity, charge transport dynamics, and reaction kinetics. The findings reveal that each electrolyte exhibits distinct advantages depending on the concentration regime, with KNO₃ offering superior conductivity and sensitivity in the high-concentration regimes, while preserving equivalent stability and reproducibility under lower concentration conditions than the alternatives. Modeling and analysis of the reaction rates highlight intrinsic electrolyte-specific variations which play a role in the overall sensitivity and selectivity of the system. These insights have significant implications for optimizing PeCOD devices in commercial and environmental applications, paving the way for further innovations in water quality monitoring and related fields.

Effective recovery of phosphorus (P) from water bodies can reduce the global shortage of P resources. Struvite formation represents one of the optimal strategies for P recovery and is widely used in wastewater treatment. However, recovery of P from P-rich groundwater via struvite remains underexplored. This study assessed three P recovery methods from groundwater containing elevated concentrations of phosphate, calcium, iron, and fulvic acid (FA). The results showed that high concentrations of calcium significantly inhibited the formation of struvite, while iron and FA exhibited comparatively limited inhibitory effects. The synergistic interaction of these three components constitutes a critical determinant for struvite formation in groundwater. Direct precipitation and ion exchange methods proved to be suboptimal for P recovery due to their low purity (∼10%). The dual-waste utilization method markedly enhanced the purity of struvite to about 35%, enabling the simultaneous recovery of solid and liquid P. The dual-waste utilization method showed superior or equivalent environmental impacts compared to the other two methods. Overall, integrating P-rich groundwater with P slag for struvite formation provides multiple benefits, including groundwater remediation, waste recycling, and fertilizer production through beneficial resource symbiosis.

Soil aquifer treatment (SAT) is operated by flooding and drying cycles, thus swiftly changing topsoil redox conditions. Currently, the links between the redox conditions, biofilm activity, and contaminants removal in SAT topsoil are not well understood. Here, two extreme-redox potentials (governed by oxic conditions) were evaluated while flooding occurred during two seasons. All tests were performed in 30 cm columns packed with SAT topsoil and flooded with artificial secondary wastewater. Redox conditions and removal efficiency of ammonia, ibuprofen, and bacteriophage, alongside bacterial activity and diversity, were determined. Biofilm activity was more intensive under aerobic than under anaerobic conditions during summer and winter (83 and 155%, respectively). Similarly, the removal of ammonia and ibuprofen was higher under aerobic conditions (82 and 54%, respectively). Differently, bacteriophage reduction was not affected by the redox conditions, as the main removal mechanism was adsorption. Additionally, biofilm richness was highly adaptive within 48 h of flooding (Shannon index: 4.7 ± 0.1) yet less diverse under anaerobic conditions. These results stress the importance of measuring and controlling the redox potential within the SAT topsoil. Moreso, continuous monitoring of the oxic conditions in the subsurface could optimize the tillage intervals as well as the wetting and drying cycles without sacrificing water quality.

Polymer-based nanomaterials have demonstrated potential as sustainable alternatives for environmental remediation. However, developing these polymer-supported nanomaterials with robust stability presents a significant challenge. The present review article summarizes different types of nanomaterials employed toward environmental remediation. These materials (adsorbents) manifest in diverse forms like particles, tubes, wires, and fibers. They form composites after being combined with polymers, which can be effectively employed to treat a range of inorganic and organic pollutants and biological agents including viruses, bacteria, parasites, and antibiotics. Nanomaterials outperform conventional environmental remediation methods due to their extensive surface area, significantly increasing their reactivity. The development of innovative polymer-supported nanomaterials (PSNMs) and techniques for treating drinking and industrial water contaminated by emerging contaminants (CECs), harmful metal ions, and organic pollutants has been underlined in recent studies. The operational mechanisms of PSNMs and their regenerative potential are closely examined to boost their reuse capabilities. Due to their superior efficiency in removing pollutants and their capacity for regeneration, PSNMs are viewed as viable replacements for current, costlier remediation technologies. The conclusions offer future perspectives, underlining the ongoing challenges and opportunities in the field and the importance of further research to enhance the efficacy and sustainability of polymer-based nanomaterials for sustainable environmental remediation.

Global warming has accelerated the degradation of alpine permafrost, significantly altering hydrological and hydrogeochemical processes in mountainous catchments. Among these changes, rock glaciers release spring waters with rising solute concentrations, including nickel levels that significantly exceed drinking water limits. This study investigates the geochemical processes driving solute mobilization in five rock glaciers in the European Alps, focusing on nickel enrichment and transport pathways. Geochemical and petrographic analyses show that high nickel concentrations in spring waters originate from sulfide minerals and their weathering products. Sulfur and oxygen isotope analyses of dissolved sulfate confirm mineral weathering as the primary solute source, while inverse hydrogeochemical modeling accurately reproduces the chemical composition of these spring waters. The hydrogeology of rock glaciers plays a critical role in these processes, as deformation and ice melt expose fresh mineral surfaces, while extended residence times of water in the subsurface create favorable conditions for natural acid rock drainage. Our study demonstrates that rock glaciers are active chemical reactors, enriching alpine streams and lakes with metals and raising concerns about water quality and ecological impacts. This work advances understanding of climate-sensitive metal contamination, informing integrated water management strategies in mountain regions.

Microplastics (MPs) can adsorb polycyclic aromatic hydrocarbons (PAHs) and potentially transfer them to biota in aquatic environments. However, the environmental fate of PAHs adsorbed on MPs remains unclear. Recent studies suggest that photolysis may dominate the fate of the MP-adsorbed PAHs. Here, we show that high temperature and snow-ice enhanced the photolysis of MP-sorbed PAHs, while their first-order photolysis rate constants were independent of the size of MPs (170–850 μm). A correlation between the enhancement factor of snow and activation energy demonstrated that the enhancement effect of snow strongly affected relatively stable PAHs adsorbed on MPs. A comparison of the quantum yields of PAHs adsorbed onto MPs and soil revealed that the suppressive effect of soil on the photolysis of PAHs was greater than that of MPs. Among the tested polymers, polypropylene (PP) showed the lowest quantum yields (3.3 × 10^–6 (benzo[a]pyrene) – 2.9 × 10^–4 (fluorene)), followed by polystyrene (PS), polyethylene terephthalate (PET), and polyethylene (PE). This study contributes to estimate the environmental fate of MPs-sorbed PAHs, as there is a concern about the environmental impact of photodegradation of MPs-sorbed PAHs in Southeast Asia, where there are high emissions of PAHs under high sea temperature, and in polar regions where they are covered by snow-ice, which enhances the photolysis.