纳米Fe^0作用下4-氯酚的脱氯特性及机理  

Reductive Dechlorination of 4-chlorophenol Using Nanosacle Iron

作　　者：程荣[1] 王建龙[1] ZHANG Wei-xian 

机构地区：[1]清华大学核能与新能源技术研究院环境技术研究室,北京100084 [2]Department of Civil and Environmental Engineering,Lehigh University, Bethlehem, PA 18015-3176, USA

出　　处：《环境科学》2007年第3期578-583,共6页Environmental Science

基　　金：国家自然科学基金项目(50325824)

摘　　要：采用化学还原法制备了纳米Fe0,ESEM测定结果表明其颗粒在1～100nm内.实验表明这些纳米Fe0能在20h内将初始浓度为20mg/L的4-氯酚完全降解,Fe0对4-CP的还原脱氯是主要去除途径.苯酚是脱氯反应的主要产物.当4-CP的初始浓度由20mg/L增大到50,100,150mg/L时,其相对去除率明显降低,但绝对降解量有较大提高.温度不仅影响脱氯速率,而且影响4-CP去除的途径.30℃时,脱氯反应为主要反应;10℃时,较易产生氧化产物.Fe原子的迁移过程在4-CP的降解中也是一个重要的限速步骤.此外,纳米Fe0具有很好的稳定性,在受试的379h内,纳米Fe0能够应对不同浓度冲击及反复投加的4-氯酚冲击的能力.Nanoscale Fe^0 was synthesized through a reductive method and the size of the particles is in the range of 1 - 100 nm, observed by ESEM image. The experimental results demonstrated that these metal particles can reduce 4-chlorophenol （4-CP） completely in 20 hours, when the initial concentration was 20 mg/L. Dechlorination by Fe^0 is the main reaction pathway, and phenol is the main product. As the concentration of 4-CP increased from 20 mg/L to 50, 100, 150 mg/L, the relative dechlorination ratio decreased obviously. But the reduced amounts of 4-CP increased. Temperature can influence dechlorination rate and change the reductive pathway. Dechlorination is the main reaction at 30℃ while some oxidized compounds may be produced at 10℃ . The transfer of iron atom may be an important factor, limiting the dechlorination rate. Moreover, the stability and durability of nanoseale Fe^0 was assessed through batch studies over extended periods of time. The results indicated that nanoscale Fe^0 can resist the shock of 4-CP concentration during 379 hours.

关 键 词：纳米铁 4-氯酚 苯酚 脱氯 地下水污染 

分 类 号：X703.1[环境科学与工程—环境工程]