State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China; Department of Chemical Engineering, Muhammad Nawaz Sharif University of Engineering and Technology, Multan 60000, Pakistan.
Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences (CAS), Suzhou 215123, China.
J Hazard Mater. 2021 Aug 15;416:125935. doi: 10.1016/j.jhazmat.2021.125935. Epub 2021 Apr 24.
Carbonaceous materials (CMs) have been applied extensively for enhancing the catalytic performance of environmental catalysts, however, the self-catalytic mechanism of CMs for groundwater remediation is rarely investigated. Herein, we unveiled the catalytic ability of various CMs via Fe(III) reduction through polyvinyl alcohol-coated calcium peroxide nanoparticles (PVA@nCP) for trichloroethylene (TCE) removal. Among selected CMs (graphite (G), biochar (BC) and activated carbon (AC)), BC and AC showed enhancement of TCE removal of 89% and 98% via both adsorption and catalytic degradation. BET and SEM analyses showed a higher adsorption capacity of AC (27.8%) than others. The generation of solution-Fe(II) and surface-Fe(II) revealed the reduction of Fe(III) on CMs-surface. The role of O-containing groups was investigated by the FTIR technique and XPS quantified the 52% and 57% surface-Fe(II) in BC and AC systems, respectively. EPR and quenching tests confirmed that both solution and surface-bound species (HO•, O• and O) contributed to TCE degradation. Acidic pH condition encouraged TCE removal and the presence of HCO negatively affected TCE removal than other inorganic ions. Both schemes (PVA@nCP/Fe(III)/BC and PVA@nCP/Fe(III)/AC) exhibited promising results in the actual groundwater, surfactant-amended solution, and removal of other chlorinated-pollutants, opening a new direction towards green environmental remediation for prolonged benefits.
碳质材料（CMs）已广泛应用于增强环境催化剂的催化性能，但 CMs 对地下水修复的自催化机制却很少被研究。在此，我们通过过氧碳酸钠（PVA@nCP）负载的纳米过氧化钙（nCP）还原三氯乙烯（TCE），揭示了不同 CMs 的催化能力。在所选择的 CMs（石墨（G）、生物炭（BC）和活性炭（AC））中，BC 和 AC 通过吸附和催化降解，使 TCE 的去除率分别提高了 89%和 98%。BET 和 SEM 分析表明，AC 的吸附能力更高（27.8%）。溶液-Fe(II)和表面-Fe(II)的生成表明 Fe(III)在 CMs 表面被还原。通过傅里叶变换红外光谱（FTIR）技术研究了 O 含量基团的作用，X 射线光电子能谱（XPS）定量分析表明，BC 和 AC 体系中表面-Fe(II)的含量分别为 52%和 57%。电子顺磁共振（EPR）和猝灭实验证实，溶液和表面结合的物种（HO•、O•和 O）均有助于 TCE 的降解。酸性 pH 条件有利于 TCE 的去除，HCO 的存在对 TCE 的去除比其他无机离子的影响更大。实际地下水、表面活性剂添加溶液以及其他氯化污染物的去除中，PVA@nCP/Fe(III)/BC 和 PVA@nCP/Fe(III)/AC 两种方案都表现出了良好的效果，为延长效益的绿色环境修复开辟了新的方向。
