施用污泥堆肥及其水溶性有机物对土壤中荧蒽解吸-淋滤的影响

以荧蒽（Fluoranthene）为多环芳烃（PAHs）的代表，通过序批试验及土柱淋洗试验研究了污泥堆肥及污泥堆肥水溶性有机物（DOM）对污染土壤中荧葸解吸和淋滤的影响．施用污泥堆肥实验结果表明，污泥堆肥施入土壤后的短时间内由于带入和产生的DOM而表现出促进土壤中荧蒽的解吸与淋滤，但随着DOM的降解，该作用逐渐消失．污泥堆肥充分腐熟后（腐熟堆肥）因DOM少而稳定的腐殖质等固相有机质含量相对较多，而表现出施用腐熟堆肥后土壤更易对荧葸吸持．单独施用污泥堆肥DOM后的试验，也进一步表明了污泥堆肥DOM的存在确实能促进土壤中荧蒽的迁移，且在相同DOM浓度下，腐熟堆肥DOM对土壤中荧蒽的解吸和淋滤的促进作用明显高于初始堆肥DOM处理，原因在于腐熟堆肥DOM中大分子组分和疏水性组分的含量比初始堆肥的DOM要多．因此，堆肥施用对土壤多环芳烃环境行为或活性的影响是堆肥施人土壤后固相有机质含量及性质和溶解性有机质的含量及性质等综合影响的结果．

Effect of sewage sludge compost and its Dissolved Organic Matter (DOM) on desorption and leaching of Fluoranthene from soil

Batch experiments and soil column experiments were performed to study desorption and leaching of Fluoranthene (FLT) from soil amended with sewage sludge compost. Results showed that the application of sludge compost raw material, instead of mature sludge compost, to PAH-polluted soil promoted the desorption and leaching of FLT within a short time after application, due to the presence of a higher concentration of Dissolved Organic Matter (DOM). However, application of the mature sludge compost facilitated soil adsorption of FLT owing to the lower concentration of DOM and higher content of solid humus in this mature compost. Comparing the result of application of DOM extracted from raw compost material with addition of mature compost to the polluted soil, showed that DOM did facilitate the mobility of FLT in the soil. Furthermore, DOM extracted from mature compost exhibited a higher ability to enhance FLT mobilization than that from raw compost material, under the same DOM concentration conditions, since the former mainly consisted of a higher molecular weight or hydrophobic fraction in comparison to the latter. Therefore, the effect of compost application on soil PAH environmental behavior is, to a great extent, dependent on the combined impact of the content and properties of solid organic matter and dissolved organic matter in the compost.