纳米Fe^0颗粒对三种单氯酚的降解

Degradation of 3 kinds of chlorinated phenols by nanoscale Fe^0.

采用化学还原法制备了纳米Fe0颗粒,研究了不同条件下纳米Fe0对3种单氯酚(2-CP,3-CP,4-CP)的去除作用.结果表明,纳米Fe0对单氯酚具有良好的去除效果,主要降解途径为先脱氯后开环,实现氯酚分子与Fe原子间的电子转移,达到还原脱氯的效果.3种单氯酚的脱氯难易程度为2-CP>3-CP>4-CP,脱氯反应活性与其分子最低空轨道能量(ELUMO)有关.随着氯酚初始浓度的增大,其相对去除率略有降低,但绝对降解量有较大提高.温度不仅影响脱氯速率,而且影响氯酚去除的途径,温度较高时,氯酚先脱氯后开环;温度低时,较易产生氧化产物.

Nanoscale Fe^0 particle was prepared adopting chemical reductive method and the reductive action of three kinds of chlorinated phenols （2-CP, 3-CP, 4-CP） by nanoseale Fe^0 under different conditions was studied. Nanoscale Fe^0 possessed good removal effect of chlorinated phenols （CPs）. The main degrading way was deehlorination first, and then cleavage of benzene ring took place, realizing the electron transfer between chlorinated phenol molecule and iron atoms, reaching the efficiency of reductive dechlorination. The dechlorination degree of 3 kinds of CPs was 2-CP〉3-CP〉4-CP. The deehlorination reaction activity was related with their energy of lowest unoccupied molecular orbit （ELUMO）. With the increase of initial concentration of CPs, its relative removal rate decreased a little; but its absolute quantity increased more greatly. Temperature could influence not only the deehlorination rate, but also influence the reaction pathway. Deehlorination was first and then the cleavage of benzene ring at higher temperature; but the oxidation product was formed more easily at lower temperature.