生物炭负载纳米零价铁材料的制备及还原降解性能

Preparation and Reductive Degradation Properties of Biochar Loaded With Nano Zero-Valent Iron

选取花生壳、稻草秸秆和玉米秸秆为原料制备不同种类生物炭,合成不同生物炭负载纳米零价铁复合材料(BC/n ZVI)。采用比表面积分析、扫描电镜等多种表征方法获得不同BC/n ZVI的物理化学和结构性质,测试BC/n ZVI对水溶液中典型有机氯农药γ-六六六的还原降解效果。结果表明,花生壳、稻草秸秆和玉米秸秆均在300℃制备条件下有较高的产率和较好的吸附效果;制备的BC/n ZVI颗粒呈球状结构,以花生壳BC/n ZVI分散性为最好;在水相实验中,添加BC/n ZVI对γ-六六六的去除效果优于单独添加生物炭或者纳米零价铁的效果;3种生物炭基材料中,花生壳BC/n ZVI对水相γ-六六六6 h的去除率为87.53%,反应体系中污染物总降解率达82.33%。

Three kinds of biochars （BCs ） were prepared from peanut shell,rice straw and corn stalk,and further into three kinds of composites of the corresponding biochar-loaded with nano zero-valent iron （BC/nZVI ）,separately, of which physic-chemical properties and structures were characterized with BET and SEM, respectively. Moreover, effects of the BC/nZVI reductively degrading y-benzene hexachloride （ BHC）,a typical organochlorine pesticide （OCP） in aqueous so-lutions were deter^nined. Results show that peanut shell,rice straw and corn stalk pyrolyzed at 300 °C turned out the high-est amounts of BCs,which were high in adsorption capacity. The prepared BC/nZVI appeared to be in spherical particle, and the one prepared out of peanut shell was the highest in dispersivity. In aqueous phase experiments, BC/nZVI was much higher than BC or nZVI in effect of removing y-BHC. Among three kinds of composites,the peanut shell based BC/ nZVI was the highest in y-BHC removal rate,reaching up to 87. 53% in aqueous solutions for six hours and had the total pollutant degradation rate reach up to 82. 33% in the reaction system.