Fe^0-C微电解去除地下水中2,4-DNT的影响因素

Influencing factors of degradation of 2,4-DNT in groundwater by Fe^0-C

采用批实验研究初始pH值、溶解氧(DO)和地下水中常见的阴、阳离子等因素对Fe^0-C微电解对地下水中2,4-二硝基甲苯(2,4-DNT)去除率的影响,并分析Fe^0-C降解2,4-DNT的产物。结果表明,在pH=7,DO=0.23 mg·L^(-1)的条件下,Fe^0-C去除溶液中2,4-DNT有明显的效果,反应200 min时,去除率达到83.09%,比Fe^0和C的去除率提高了74.56%和9.89%;酸性条件下有利于2,4-DNT去除,初始pH=5的条件下,溶液中2,4-DNT的去除率为82%,而初始pH=10时,2,4-DNT的去除率分别为64%;反应体系中含有较高浓度的溶解氧有利于2,4-DNT的去除,在DO=9.26 mg·L^(-1)条件下,2,4-DNT的去除率比DO=0.23 mg·L^(-1)时提高了9.5%;地下水中一定浓度的阴(Cl-、SO_4^(2-))、阳离子(Ca^(2+)、Mg^(2+)、Na^+、K^+)可以提高2,4-DNT的去除率,提高率小于10%。反应过程中2,4-DNT降解的产物包括2-氨基-4-硝基甲苯(2A4 NT)、4-氨基-2-硝基甲苯(4A2 NT)和2,4-二氨基甲苯(2,4-DAT)。

In this study, batch experiments were conducted to investigate the impact of initial pH, dissolved ox- ygen （DO） , and common cations/anlons on the reductive capabilities of Fe0-C for 2,4-dinitrotoluene （2,4- DNT） , and the products from such a reaction were analyzed. Fe0-C removed 2,4-DNT remarkably at pH = 7 and DO =0.23 mg· L-1. The removal efficiency reached 83.09% after 200 min. Compared to Fe0 and C singly, 2, 4-DNT removal efficiency by the combined Fe0-C increased by 74.56% -1 9.89%. Acidic conditions favored the removal of 2,4-DNT. The results demonstrated that the removal rate of 2,4-DNT reached 82% when pH = 5. When pH = 10, the removal efficiency of 2,4-DNT was 64%. The removal rate increased 9.5% when DO in- creased from 0.23 mg · L-1 to 9.26 mg · L-1. Common cations and anions in groundwater influenced 2,4-DNT removal. The degradation products from 2,4-DNT reduction included 2A4 NT, 4A2 NT, and 2,4-DAT.