The Chinese Journal of Process Engineering•2026•DOI: 10.12034/j.issn.1009-606X.225221
The proliferation of lithium-ion batteries (LIBs) in portable electronics and electric vehicles has generated a pressing need for sustainable recycling of spent batteries. Conventional pyrometallurgical and hydrometallurgical routes suffer from low metal recovery efficiencies or require additional precipitants. This study introduces a clean and efficient process for recovering lithium (Li) and cobalt (Co) from spent LiCoO2 cathode materials using a choline chloride-oxalic acid-water (ChCl-OA-H2O) deep eutectic solvent (DES). The method exploits selective precipitation of Co as cobalt oxalate dihydrate (CoC2O4·2H2O) followed by water-content-regulated recovery of Li as lithium oxalate (Li2C2O4) via evaporation crystallization, eliminating the need for external precipitants. Under optimized conditions (molar ratio 1:1:8, solid-liquid ratio 100 g/L, 90 °C, 6.5 h), the leaching efficiency of Li reached 99.4%, with recovery efficiencies of 88.3% for Li and 97.8% for Co. The DES system demonstrated robust cycling stability, maintaining Li and Co recoveries of 78.1% and 92.8% after six regeneration cycles. This work provides a low-pollution, economically viable pathway for LIB recycling, contributing to resource sustainability and offering significant industrial potential.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202508050
This study investigated the spatial distribution and ecological risk of heavy metals (As, Cd, Cr, Cu, Ni, Pb, Zn) in soil beneath an informal waste dump in a pastoral area of Baingoin County, Nagqu City, Tibet, a high-altitude cold region with frequent freeze-thaw cycles. A total of 55 soil samples were collected from surface (0 cm), middle (10-30 cm), and deep (50 cm) layers. Single-factor index (Pi), geo-accumulation index (Igeo), Nemerow index (PN), and risk assessment code (RAC) were employed to evaluate contamination levels and potential ecological risks, while Kriging interpolation was used to map spatial distribution. Results showed that average concentrations of all seven heavy metals exceeded local background values. Horizontally, high-concentration zones were mainly located at five points within the dump. Vertically, Cd, Cu, Pb, and Zn were significantly enriched in the surface layer, whereas Ni exhibited higher concentrations in deeper layers, indicating downward migration driven by freeze-thaw processes. All evaluation methods identified Cd as the primary pollutant. Speciation analysis revealed that heavy metals were predominantly in the residual fraction, with Ni having the highest weak-acid-extractable fraction (5.55%), indicating strong mobility and potential biological toxicity. This study fills a gap in systematic research on informal waste dumps in high-altitude ecologically fragile areas and provides a case reference for environmental management and remediation of such sites in cold regions.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202605001
The lower reaches of the Yangtze River Basin, as a concentrated area of China's C5 petroleum resin industry, face critical bottlenecks in green and low-carbon transformation due to high-pollution, refractory wastewater and high carbon emissions. Traditional petrochemical wastewater treatment technologies suffer from low efficiency, high energy consumption, and insufficient resource utilization. This paper systematically analyzes the sources of wastewater in C5 petroleum resin production from principles and processes, and reviews research progress and carbon reduction potential of current technologies in three aspects: new materials, new equipment, and new processes. Integrated processes centered on efficient pretreatment, biological enhancement, and multi-technology coupling show significant advantages in improving treatment efficiency, reducing energy consumption and cost, and strengthening resource recovery. The study also prospects future research priorities for pollution and carbon mitigation through green technological innovation and intelligent upgrading, providing new solutions for 'near-zero discharge' and resource recycling of C5 petroleum resin wastewater, thereby promoting the green and low-carbon transformation of the petrochemical industry.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2026012804
This study conducted online monitoring of volatile organic compounds (VOCs) at a roadside site on a main arterial road in Haikou, a tropical city, during summer 2023 (June 25–September 30). A total of 56 VOCs were measured. The mean total VOC concentration (φ(TVOCs)) was (9.05 ± 6.24) nmol·mol−1, with concentrations in the order: alkanes > alkenes > aromatic hydrocarbons > alkynes, dominated by light alkanes. Alkenes and aromatic hydrocarbons contributed significantly to atmospheric chemical reactivity, while secondary organic aerosol formation potential (SOAFP) was limited, influenced by both VOC concentrations and temperature. VOC concentrations exhibited a pronounced bimodal diurnal pattern, consistent with traffic peaks. Ratio analysis indicated a Toluene/Benzene (T/B) ratio slightly higher than typical vehicle exhaust values, and an iso-Pentane/n-Pentane (i/n) ratio suggesting fuel evaporation influence. Positive Matrix Factorization (PMF) identified four sources: gasoline/LPG vehicle exhaust (49.9%), solvent use or vehicle evaporation (26.1%), diesel vehicle exhaust (14.9%), and biogenic sources (9.1%). SOAFP was mainly contributed by solvent use/evaporation (35.7%), gasoline/LPG exhaust (34.6%), diesel exhaust (22.0%), and biogenic sources (7.7%). These findings indicate that under tropical summer high-temperature conditions, roadside VOC pollution is predominantly traffic-related, with vehicle evaporation sources non-negligible, providing insights for evaluating vehicular impacts on particulate pollution.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4107-x
Aqueous fiber zinc-iodine batteries (FZIBs) with four-electron redox exhibit inherent safety and high energy density for wearable electronics. Nevertheless, their practical implementations are hindered by unsatisfactory cycling stability and low realistic energy density, mainly caused by severe H2O-induced nucleophilic attack toward iodine species and poor zinc anode reversibility. Here, we report a quaternary ammonium-mediated coordination strategy to simultaneously address the irreversible cathode/anode redox behavior and thus promote the electrochemical performance of four-electron FZIBs. The cationic choline ion (Ch+) induces complexation with ICl2− via electrostatic interaction, homogenizing the electron cloud density and suppressing irreversible hydrolysis of I+ species, enabling a reversible near-theoretical high capacity of 418.3 mAh g−1. Meanwhile, preferentially adsorbed Ch+ on the zinc anode surface creates positively charged shielding layers, mitigating the tip effect caused by localized electric field and achieving robust zinc stripping/plating. The enhanced cathode/anode reversibility and improved interfacial stability enable stable FZIBs operation for over 20,000 cycles at 20.0 A g−1. Moreover, successful integration of FZIBs into electronic textiles with glucose and cardiac rhythm sensors demonstrates great potential for next-generation wearable electronics.