Abstract：
Dibromoethane is a widespread, persistent organic pollutant. Biochars are known mediators of reductive dehalogenation by layered FeII-FeIII hydroxides (green rust), which can reduce 1,2-dibromoethane to innocuous bromide and ethylene. However, the critical characteristics that determine mediator functionality are lesser known. Fifteen biochar substrates were pyrolyzed at 600 °C and 800 °C, characterized by elemental analysis, X-ray photo spectrometry C and N surface speciation, X-ray powder diffraction, specific surface area analysis, and tested for mediation of reductive debromination of 1,2-dibromoethane by a green rust reductant under anoxic conditions. A statistical analysis was performed to determine the biochar properties, critical for debromination kinetics and total debromination extent. It was shown that selected plant based biochars can mediate debromination of 1,2-dibromoethane, that the highest first order rate constant was 0.082/hr, and the highest debromination extent was 27% in reactivity experiments with 0.1 µmol (20 µmol/L) 1,2-dibromoethane, ≈ 22 mmol/L FeIIGR, and 0.12 g/L soybean meal biochar (7 days). Contents of Ni, Zn, N, and P, and the relative contribution of quinone surface functional groups were significantly (p < 0.05) positively correlated with 1,2-dibromoethane debromination, while adsorption, specific surface area, and the relative contribution of pyridinic N oxide surface groups were significantly negatively correlated with debromination.
摘要：
二溴乙烷是一种普遍存在的,持久性有机污染物。生物炭是已知的通过层状FeII-FeIII氢氧化物（绿锈）还原脱卤的介体，可以将1,2-二溴乙烷还原为无害的溴化物和乙烯。然而,确定介体功能的关键特征鲜为人知。在600°C和800°C下热解了15种生物炭底物，通过元素分析表征，X射线光谱C和N表面形态，X射线粉末衍射,比表面积分析，并测试了在缺氧条件下通过绿锈还原剂对1,2-二溴乙烷的还原脱溴作用。进行统计分析以确定生物炭的性质，脱溴动力学和总脱溴程度至关重要。研究表明，选定的植物基生物炭可以介导1,2-二溴乙烷的脱溴，最高的一阶速率常数为0.082/hr，在0.1µmol（20µmol/L）1,2-二溴乙烷的反应性实验中，最高脱溴程度为27％，≈22mmol/LFeIIGR，和0.12g/L豆粕生物炭(7天)。Ni的含量,Zn,N,P,醌表面官能团的相对贡献与1,2-二溴乙烷脱溴反应呈显著正相关(p<0.05),而吸附，比表面积,吡啶N氧化物表面基团的相对贡献与脱溴反应呈显著负相关。
