潮棕壤中DnBP和DEHP的降解及其对土壤呼吸作用的影响

Degradation of DnBP and DEHP in Aquic Brown Soil and Its Effects on Soil Respiration

以潮棕壤为供试土壤,采用土壤培养试验结合超声波提取法与气相色谱检测技术,研究了邻苯二甲酸正二丁酯(DnBP)和邻苯二甲酸二(2-乙基己)酯(DEHP)的降解动力学过程及其对土壤呼吸作用的影响规律,以期为邻苯二甲酸酯类(PAEs)污染土壤的修复与健康风险评估提供参考依据。结果表明:在试验浓度范围内,DnBP的降解半衰期为5.3~13.9 d,DEHP的降解半衰期为15.2~31.0 d,且半衰期随污染浓度的升高而延长,表明初始污染浓度对邻苯二甲酸酯类(PAEs)的微生物降解具有较大影响;土壤CO_(2)释放量随DnBP和DEHP的降解呈现动态变化,土壤呼吸作用强度与土壤中DnBP和DEHP的降解速率呈极显著正相关关系,表明DnBP和DEHP污染促进了土壤呼吸作用。

The degradation kinetics of DnBP and DEHP in tidal brown soil and their effects on soil basal respiration were studied by soil incubation experiments,ultrasonic extraction and gas chromatography,in order to provide reference for the remediation of PESa contaminated soil and health risk assessment.The results showed that the degradation half-lives of DnBP ranged from 5.3 to 13.9 days and those of DEHP ranged from 15.2 to 31.0 days in the tested concentration range.When the half-lives increased with the increase of pollution concentration,indicating that the initial pollution concentration had a great impacton the microbial degradation of phthalic acid esters(PAEs).The amount of soil CO_(2) released dynamically was changing with the degradation of DnBP and DEHP,and the intensity of soil respiration which had a very significant positive correlation with the degradation rate of DnBP and DEHP in the soil.It indicated that DnBP and DEHP pollution had promoted soil respiration.