School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418, China.
Key Lab of Eco-Restoration of Regional Contaminated Environment, Ministry of Education, Shenyang University, Shenyang 110044, China.
Molecules. 2023 Mar 31;28(7):3145. doi: 10.3390/molecules28073145.
1,1,1-Trichloroethane (1,1,1-TCA) is a typical organochloride solvent in groundwater that poses threats to human health and the environment due to its carcinogenesis and bioaccumulation. In this study, a novel composite with nanoscale zero-valent iron (nZVI) supported by polycaprolac-tone (PCL)-modified biochar (nZVI@PBC) was synthesized via solution intercalation and liquid-phase reduction to address the 1,1,1-TCA pollution problem in groundwater. The synergy effect and improvement mechanism of 1,1,1-TCA removal from simulated groundwater in the presence of nZVI@PBC coupling with CN32 were investigated. The results were as follows: (1) The composite surface was rough and porous, and PCL and nZVI were loaded uniformly onto the biochar surface as micro-particles and nanoparticles, respectively; (2) the optimal mass ratio of PCL, biochar, and nZVI was 1:7:2, and the optimal composite dosage was 1.0% (w/v); (3) under the optimal conditions, nZVI@PBC + CN32 exhibited excellent removal performance for 1,1,1-TCA, with a removal rate of 82.98% within 360 h, while the maximum removal rate was only 41.44% in the nZVI + CN32 treatment; (4) the abundance of CN32 and the concentration of adsorbed Fe(II) in the nZVI@PBC + CN32 treatment were significantly higher than that in control treatments, while the total organic carbon (TOC) concentration first increased and then decreased during the culture process; (5) the major improvement mechanisms include the nZVI-mediated chemical reductive dechlorination and the CN32-mediated microbial dissimilatory iron reduction. In conclusion, the nZVI@PBC composite coupling with CN32 can be a potential technique to apply for 1,1,1-TCA removal in groundwater.
1,1,1-三氯乙烷（1,1,1-TCA）是地下水环境中典型的有机氯溶剂，由于其具有致癌性和生物蓄积性，对人类健康和环境构成威胁。本研究通过溶液插层和液相还原法，制备了负载于聚己内酯（PCL）改性生物炭（nZVI@PBC）上的纳米零价铁（nZVI）复合材料，以解决地下水 1,1,1-TCA 污染问题。考察了 nZVI@PBC 与 CN32 偶联去除模拟地下水中 1,1,1-TCA 的协同作用及改进机制。结果表明：（1）复合材料表面粗糙多孔，PCL 和 nZVI 分别以微颗粒和纳米颗粒的形式均匀负载在生物炭表面；（2）PCL、生物炭和 nZVI 的最佳质量比为 1:7:2，最佳复合剂量为 1.0%（w/v）；（3）在最优条件下，nZVI@PBC+CN32 对 1,1,1-TCA 具有优异的去除性能，360 h 内去除率达到 82.98%，而 nZVI+CN32 处理的最大去除率仅为 41.44%；（4）nZVI@PBC+CN32 处理中 CN32 的丰度和吸附 Fe（II）的浓度明显高于对照处理，而总有机碳（TOC）浓度在培养过程中先升高后降低；（5）主要的改进机制包括 nZVI 介导的化学还原脱氯和 CN32 介导的微生物异化铁还原。综上所述，nZVI@PBC 复合材料与 CN32 耦合可作为一种潜在的技术，应用于地下水 1,1,1-TCA 的去除。
