摘要
采用购买的纳米铁以及实验室合成的纳米钯化铁对3种高氯苯进行吸附和降解批量实验.结果表明,纳米铁在不同溶液体系下其吸附性能存在显著差异,其中采用pH=6.8的Tris缓冲体系时,纳米铁达到最大吸附值.纳米钯化铁在20 h内对浓度为1 mg.L-1的1,2,4,5-TeCB具有很好的降解效果,在纯水和缓冲体系中的降解率分别为75%和92%;而纳米铁对1,2,4,5-TeCB的降解效果较差,降解率只有25%左右;相同时间内,纳米钯化铁对PeCB和HCB的降解率仅为20%左右;降解产物仅检测到1,2,3,4-TeCB、1,2,3-TCB、1,2-DCB,说明纳米铁和钯化铁对高氯苯作用的优选脱氯位置是空间位阻少的氯原子;高氯苯的降解符合准一级动力学反应,速率常数介于0.014 4～0.115 2 h-1之间.
Adsorption and degradation of three typical chlorinated benzenes（CBs） were evaluated using commercial nanoscale Fe（nFe） and synthesized palladized Fe（Pd/nFe） via batch experiments.The results showed that the adsorption capacity exhibited significant difference between various conditions,of which its maximum adsorption amount reached with Tris-buffered solution of pH = 6.8.1,2,4,5-TeCB can be dechlorinated by Pd /nFe efficiently within 20 hours.The degradation rates were 75% and 92% in pure water system and Tris-buffered solution,respectively.However,nFe seemed to be inactive to 1,2,4,5-TeCB with final degradation rate of about 25%.Meanwhile,Pd /nFe also only had slight degradation capacities to HCB and PeCB when compared to 1,2,4,5-TeCB.1,2,3,4-TeCB,1,2,3-TCB and 1,2-DCB are the only products that were detected during the whole experiments,indicating that chlorine atoms of CBs with less steric effect were preferred to be dechlorinated.The degradation can be fitted by pseudo first order equations.The observed rate constants were ranged from 0.014 4 h-1 to 0.115 2 h-1.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2011年第3期692-698,共7页
Environmental Science
基金
国家自然科学基金项目(20707028
40701078
40771104)
国家高技术研究发展计划(863)项目(2009AA063103)
关键词
氯苯
厌氧降解
还原脱氯
纳米铁
钯化铁
chlorinated benzenes（CBs）
anaerobic degradation
reductive dechlorination
nanoscale iron
palladized iron
作者简介
作者简介：李杰（1984～），男，硕士研究生，主要研究方向为环境污鎏警劁技术，E-mail：jieli@issas．ac．cn
通讯联系人，E-mail：jiangxin@issas．ac．cn
