Fenton氧化对土壤有机质及其吸附性能的影响

利用3种土壤在室内研究了Fenton氧化对土壤有机质含量和组成的影响,以及由此引起的土壤对有机污染物(芘)吸附性能的变化。结果表明,Fenton氧化处理后,土壤有机质含量和组成均发生了改变,总有机质含量下降,其中腐植酸含量降低最多,胡敏素的含量基本保持不变,而富里酸含量有升高的趋势。芘在氧化后的3种土壤中的分配系数(Kd)都有降低;将Kd与土壤有机质各成分进行相关分析研究发现,有机质中胡敏素和腐植酸一起决定有机污染物的吸附行为,其中胡敏素为关键因素。因为土壤有机质各成分的分布不同,所以有机碳含量标化分配系数(Koc)相差很大,特别是在腐植酸含量相对较高的土壤中,由于腐植酸大部分降解为吸附能力小的富里酸,Koc有明显降低,而在腐植酸含量相对较低的土壤中Koc变化不明显。

Influence of Fenton Oxidation on Soil Organic Matter and Its Sorption Characteristics

The influence of Fenton oxidation on soil organic matter(SOM)content and composition and the consequent change of sorption ability of organic pollutants(pyrene)were investigated in this study.3 types of soil samples were chosen as the tested soils.The results showed that contents of total SOM and humic acid in soil decreased after Fenton oxidation,while humin content in soil did not change significantly,and the content of fulvic acid had a tendency to increase.Sorption coefficient(Kd)values of pyrene on the three soils decreased after the soil oxidation.Correlation analysis between Kd value and different fractions of the SOM revealed that both humin and humic acid are 2 key factors in the sorption of organic pollutants,and the role of humin was more important.Sorption coefficient normalized by organic content(Koc)varied greatly after oxidation due to the different SOM composition distribution after oxidation.The decrease of Koc was significant in soils with high humic acid content because large part of humic acid was transformed to fulvic acid,whose sorption ability was low.And for the same reason,the change of Koc by oxidation in the soil with lower humic acid content was less significant.