农村固体废弃物堆肥胡敏酸还原土壤Fe3+矿物研究

Structure Evolution of Compost-derived HAs from Rural Solid Waste and Corresponding Reduction of Fe3+ Mineral from Soil

摘要:

堆肥胡敏酸作为农村固体废弃物资源化处置的重要产物，除具有保水保肥的功能外，还具有氧化还原特性。针对农村固体废弃物堆肥胡敏酸结构特性，进行了堆肥全过程胡敏酸结构演变对土壤Fe3+矿物还原特性研究。结果表明，随堆肥进行，堆肥胡敏酸芳香化、腐殖化加剧，氧化还原功能基团、组分含量增加，可有效促进土壤Fe3+矿物还原。醌基团是堆肥胡敏酸重要的氧化还原功能基团，堆肥中后期木质纤维素降解释放醌基团，经缩合作用与堆肥胡敏酸结合加速堆肥腐殖化进程，增强堆肥胡敏酸氧化还原性能，提升Fe3+矿物还原能力。

Abstract:

Low efficiency of resource utilization of rural solid wastes resulted in more and more serious environmental pollution in rural areas. As a significant resource approach of rural solid wastes, compost has been widely used. Compost-derived HAs as the important products of solid waste compost were confirmed to be redox recently. Whether compost-derived HAs were similar to natural HAs to be able to promote the reduction of Fe3+ mineral was unclear. The rural solid wastes compost continued 40d in an indoor composting reactor. Physical and chemical indexes changes during composting confirmed the successful rural solid waste compost. Spectra results of compostderived HAs indicated that the aromaticity, humification and content of redox functional groups of compostderived HAs were all increased during composting, which would facilitate the reduction of Fe3+ minerals. Specific UV absorbance values of compost-derived HAs demonstrated that quinones were the main redox functional groups within compost-derived HAs, which were mainly derived from the degradation of lignocellulose in compost materials in middle- and later-stage compost. Then these quinones would combine with the compost-derived HAs which would accelerate the humification of compost-derived HAs, increase their redox properties and the reduction of Fe3+ minerals and facilitate the degradation of organic contaminants in soil.