季铵盐阳离子表面活性剂改性活性炭对农药毒死蜱的吸附

活性碳具有多孔结构,对农药具有强烈的吸附作用.利用十六烷基三甲基溴化胺(HTAB)、溴代十六烷基吡啶(HPB)、四丁基溴化胺(TBAB)三种季铵盐阳离子表面活性剂对活性炭进行表面改性.利用比表面积测定、元素分析以及X射线荧光光谱等对吸附剂进行了表征,研究了改性活性炭对农药毒死蜱的吸附性能.结果表明,毒死蜱在活性炭上的吸附行为符合Freundlich方程.改性后的活性炭对水中毒死蜱的吸附量显著提高,与改性前相比,三种改性活性炭对有机物的吸附量分别提高了1.0、1.1、2.5倍,三种改性活性炭对毒死蜱吸附能力大小顺序为C-TBAB＞C-HTAB＞C-HPB,并且酸性条件有利于吸附的进行.     

活化过硫酸盐和芬顿反应修复有机磷农药污染土壤的比较研究

Organophosphorus pesticides (OPs) are one of the most regular pollutants and frequently detected in the contaminated sites,so developing an efficient method for the treatment of OPs is highly required.The aim of the present study was to compare the effectiveness of persulfate (PS) activation and Fenton reaction in remediating the soil polluted with OPs.The polluted soil used in this study was sampled from an abandoned insecticide factory in Nantong,Jiangsu Province of China,mainly containing chloropyrifos (CP) and 4-bromo-2-chlorophenol (BCP,the raw material of profenofos) with total concentration of about 30 000 mg kg-1.The results showed that both BCP and CP were efficiently degraded by base activation of PS,and increasing the ratio of NaOH/PS enhanced CP degradation,but slightly decreased BCP degradation.The greatest degradation rates for CP and BCP were 92％ and 97％,respectively,with 7.0 mol L-1 NaOH and 0.21 mol L-1 PS and a soil-to-liquid ratio of 1:1.Furthermore,ferrous iron activation of PS also degraded BCP efficiently,but only 60％ of CP was degraded under the same reaction conditions.These results indicated that base activation of PS was more feasible than Fe2+ activation and Fenton reaction in remediating the soil polluted with OPs.The high degradation rate for CP may be linked to the initial hydrolyzation of CP by base to 3,5,6-trichloro-2-pyridinol,which can be further rapidly degraded by free radicals generated from base activation of PS.