抗坏血酸还原降解土壤中的阿特拉津

DEGRADATION OF ATRAZINE IN CONTAMINATED SOIL BY ASCORBIC ACID

研究了抗坏血酸还原降解土壤中阿特拉津的效率、影响因素和途径。结果表明:抗坏血酸能有效降解土壤中阿特拉津。当抗坏血酸浓度为20 mmol/L,初始pH为7.0,温度为20℃时,土壤中阿特拉津降解率达到85.5%,降解速率为0.117 d-1。氧气会增加抗坏血酸的消耗量,从而抑制土壤中阿特拉津的降解。在20~50℃内增加反应温度能促进土壤中阿特拉津的降解,抗坏血酸降解土壤中阿特拉津的表观活化能为22.6 kJ/mol。抗坏血酸在碱性条件下降解阿特拉津的效率显著高于中性和酸性。抗坏血酸降解阿特拉津的途径主要包括脱氯、脱烷基和羟基化反应。

The degradation efficiency,influencing factors and degradation pathway of atrazine in contaminated soil by ascorbic acid was investigated in this study.The results showed atrazine in contaminated soil could be efficiently degraded by ascorbic acid.With addition of 20 mmol/L ascorbic acid,the degradation ratio and degradation rate of atrazine in contaminated soil reached 85.5%and 0.117 d-1 respectively,at pH of 7.0 and temperature of 20℃.The presence of oxygen could increase the consumption of ascorbic acid which led to the inhibition of atrazine degradation.In the range of 20~50℃,the increase of reaction temperature could enhance the degradation of atrazine in contaminated soil.The apparent activation energy of atrazine was 22.6 kJ/mol in ascorbic acid reduction process.The degradation ratio of atrazine in contaminated soil by ascorbic acid at alkaline pH was much higher than neutral pH and acid pH.The degradation pathway of atrazine by ascorbic acid included dichlorination,dealkylation and hydroxylation.