Environmental Science & Technology Letters Environ.最新文献

Marine carbon dioxide removal (mCDR) is increasingly recognized as a potential mitigation pathway to achieve the goals of the Paris Agreement. Among the scalable and cost-effective options for mCDR, ocean alkalinity enhancement (OAE) stands out as a potential eco-friendly option. Herein, a novel OAE strategy on the basis of coupled electrochemical alkalinization and CaCO₃ dissolution is developed for the removal of influent CO₂ in ambient conditions. The laboratory strategy also considers the additional benefit of converting dissolved nitrite, which can be toxic at high concentrations in seawater. The protons produced in the anodic sector are neutralized by timely dissolution of CaCO₃ powders, which converts an equivalent mole of dissolved inorganic carbon. The alkalinity generated in the cathodic sector reacts with influent CO₂ to form bicarbonate anions in seawater. As a result, the integrated OAE design produces increased total alkalinity and dissolved inorganic carbon in seawater with a relatively moderate energy consumption of 104.5 kJ/mol of CO₂ and high electron efficiency. In addition, the anodic reaction converts nitrite to nitrate. The proof-of-concept module thus provides an eco-beneficial pathway for mCDR. A potential environmental scenario could be the integration of OAE and wastewater treatment in intensive and recirculating marine aquaculture.

Addressing the challenges of ion adsorption capacity and electrode stability in capacitive deionization (CDI), this research introduces a pioneering anion exchange membrane (AEM)-based rocking chair CDI (RCDI) system equipped with activated carbon electrodes. Designed to counteract co-ion effects, this AEM-RCDI system significantly enhances ion-selective adsorption through improved electrode surface charge dynamics. This study also elucidates how these dynamics influence electrode potential distribution, the potential of zero charge, and the mechanism facilitating differential adsorption of ions, bridging fundamental electrochemical insight with practical improvement in desalination performance. Our investigation reveals that the oxidation of the carbon electrode, both during desalination and through targeted preoxidation, significantly boosts desalination efficacy and electrode stability. Especially, preoxidation increases cation adsorption, achieving an impressive desalination capacity of 87.3 mg g^–1, rate of 12 mg g^–1 min^–1, and charge efficiency of 88.6%, with remarkable stability over 240 desalination cycles. This study not only unveils key insights into the deionization mechanisms and properties of carbonaceous electrodes in RCDI but also sets a new benchmark for commercial CDI development.

Time trends in atmospheric concentrations serve to evaluate how effective the Stockholm Convention is in reducing or eliminating environmental releases of persistent organic pollutants (POPs). Twelve years (2005–2016) of continuous monitoring with a global network of 20 sampling sites reveals that concentrations of the pesticide endosulfan began to drop coincident with its listing as POP in 2011. Concentrations of other POPs started to decrease prior to listing and during the sampling period declined very slowly or not at all. Concentrations of some unintentionally produced POPs (hexachlorobenzene, hexachlorobutadiene) increased to become the most abundant and most widely dispersed POPs in the global atmosphere. Their formation processes and release locations need to be identified to facilitate the Convention’s goal of curbing releases from unintentional production.

Despite the ubiquitous use of textiles, the chemical additives used in textile manufacturing, their human exposure, and their environmental release have been largely overlooked. Herein, we screened for numerous chemical additives, including synthetic antioxidants, organophosphate esters, and phthalate esters, detecting 93 of 98 chemicals in 78 items of clothing (sum concentration: 328 to 2.51 × 10⁵ ng/g, median: 2.77 × 10⁴ ng/g). Compared with organophosphate esters and phthalate esters, significantly high concentrations of synthetic antioxidants (median: 2.51 × 10⁴ ng/g) were found in clothes for both children and adults. Different chemical compositions were observed between cotton and artificial fabrics, with 3 times higher concentrations observed in clothing for children than for adults. Dermal contact via sweaty clothes may be a major exposure pathway for 2,4-di-tert-butyl-phenol (contributing 39.1% to total exposure); thus, it is recommended to avoid rewearing sweaty clothes to minimize human exposure. Additionally, environmental emissions of chemicals through laundry wastewater were estimated at 11.2 tons/year in China. The discharge of 2,6-di-tert-butyl-p-benzoquinone via laundry wastewater contributed 20.4% of the total input into wastewater treatment plants in China, indicating a non-negligible source of this chemical. This work provides comprehensive evidence of unwanted chemical additives in clothes and underscores the necessity for continuous monitoring of environmental and human risks associated with textile products.

Carboxylic acids play an important role in atmospheric photochemical reactions, aerosol nuclei, and climate change. Primary and secondary carboxylic acid emissions from various combustion scenarios were quantified. Coal combustion emitted more low-molecular weight (MW) monocarboxylic acids (<C9) (12.7–16.4%), while biomass burning released more ultrahigh-MW monocarboxylic acids (>C29) (15.5–32.3%). Ultrahigh-MW monocarboxylic acid abundance and hexadecanoic acid (C16) versus nonadecanoic acid (C19) remained stable between the primary emission and aging processes, suggesting that they could be ideal markers for source characterization. Significant correlations were observed between the decreasing of toluene and benzene and the increasing of oxalic acid (C2), malonic acid (C3), fumaric acid (C4), suberic acid (C8), azelaic acid (C9), and sebacic acid (C10) (p < 0.05) during coal combustion, suggesting that oxidation of toluene and benzene lead to the formation of dicarboxylic acids during photochemical aging. On the other hand, the oxidation of monocarboxylic acids occurs on carbons farther away from the −COOH group, leading to the formation of dicarboxylic acids. The secondary formation mechanism of dicarboxylic acids from biomass burning differed from that of coal because of the abundance of low-chemical reactivity, ultrahigh-MW monocarboxylic acids; further study is required.

Inhalation of viable airborne pathogens often leads to respiratory infections. Among the different factors that affect the survival of airborne pathogens, specific aerosol composition, such as secondary organic aerosol (SOA), may impact the severity of respiratory infection by stimulating host cell apoptotic responses. Here, we studied the in vitro effects of SOA (biogenic and anthropogenic) on respiratory infection of the human influenza A virus (H1N1). Viral gene copies in the human bronchial epithelial cell line (BEAS-2B) and human fetal lung fibroflast cell line (MRC-5) treated with SOA were measured to be significantly different from the control group. A maximum enhancement of 56%, 77%, and 45% in H1N1 replication was observed for BEAS-2B cells exposed to different doses of α-pinene SOA, toluene SOA, and naphthalene SOA, respectively. SOA from various precursors impacted viral replication differently, indicating the importance of emission source and composition. For BEAS-2B cells, anthropogenic SOA (toluene and naphthalene) significantly suppressed viral replication at low doses (1 μg mL^–1 and 5 μg mL^–1) and enhanced viral replication at higher doses. Interplay among the source, composition, oxidative stress, host cell apoptosis, and respiratory viral infection highlights the importance of having air pollution mitigation strategies out of a public health perspective.

Reducing methane (CH₄) emissions from natural gas (NG) pipeline leaks is crucial to minimize global warming while also providing key safety benefits to communities. What is not well understood about pipeline leak scenarios is the impact of different soil surface conditions on the belowground leak transport behavior and subsequently the NG leak classification. In this study, we conducted a series of controlled leak experiments, varying based on the surface conditions including snow, moist soil layers, asphalt, and grass. Data indicated that temporary rain and snow surface cover conditions result in CH₄ concentrations extending 3 times further than the equivalent leak scenario under dry soil conditions, resulting in levels that pose heightened environmental and safety risks. Furthermore, after leak termination, CH₄ trapped under snow, moist soil, and asphalt surface conditions persisted for up to ∼12 days, with 5–15% CH₄ (v/v) conditions persisting underground for 7.5 days. Even after leak termination, NG continued to migrate laterally away from the leak source, extending the plume boundary by 2–4%. While efforts to study a wider range of environmental conditions are underway, the findings of this study provide crucial insight into identifying and prioritizing leaks from the perspectives of both safety and the environment.

Fertilizer utilization is critical for food security. This study examines the occurrence of trace elements (TEs) and Sr isotope (⁸⁷Sr/⁸⁶Sr) variations in phosphate rocks and mineral fertilizers from a sample collection representative of major phosphate producing countries. We show high concentrations of several TEs in phosphate rocks (n = 76) and their selective enrichment in phosphate fertilizers (n = 40) of specific origin. Consistent with the concentrations in parent phosphate rocks, phosphate fertilizers from the U.S. and Middle East have substantially higher concentrations of U, Cd, Cr, V, and Mo than those in fertilizers from China and India. Yet, fertilizers from China and India generally have higher concentrations of As. The ⁸⁷Sr/⁸⁶Sr in phosphate fertilizers directly mimic the composition of their source phosphate rocks, with distinctive higher ratios in fertilizers from China and India (0.70955–0.71939) relative to phosphate fertilizers from U.S. and Middle East (0.70748–0.70888). Potash fertilizers have less Sr and TEs and higher ⁸⁷Sr/⁸⁶Sr (0.72017–0.79016), causing higher ⁸⁷Sr/⁸⁶Sr in mixed NPK-fertilizers. Selective extraction (Mehlich III) of soils from an experimental agricultural site shows relative enrichment of potentially plant-available P, Sr, and TEs in topsoil, which is associated with Sr isotope variation toward the ⁸⁷Sr/⁸⁶Sr of the local utilized phosphate fertilizer.