改性碳纳米材料钝化堆肥重金属过程吸附解吸动力机制与钝化材料环境释放效应-以草坪用地为例

垃圾堆肥与污泥堆肥含有大量的有机质和植物营养元素，土地利用是实现其资源化利用的有效方式。但堆肥中还含有重金属，为了避开食物链，两种堆肥被广泛用于绿化用地（如草坪）。堆肥的土地利用，成为加剧土壤重金属污染的重要因素之一。另外，碳纳米材料具有极大的比表面积和丰富的孔结构，经改性处理后表面含有大量的含氧功能团，对重金属具有较强的吸附性，在重金属污染治理方面应用前景广阔。鉴于此，将两种纳米碳材料-石墨烯和纳米碳黑改性后添加到堆肥中，通过草坪建植，研究改性纳米碳材料对堆肥重金属的吸附动力学机制及其环境释放效应，主要包括：堆肥重金属在土壤-植物体系迁移的空间变异行为；堆肥重金属有效态与残渣态转化的吸附解吸平衡动力学机制；土壤性质、土壤酶、土壤生态指示生物类群响应特征，以达到认识改性纳米碳材料钝化堆肥重金属的机理及其环境释放效应的目的。研究最终为各类含重金属堆肥的安全利用及重金属钝化修复提供科学依据。

Municipal solid waste (MSW) and sewage sludge (SS) compost contain valuable plant nutrients and organic matter that can improve soil fertility and crop yield. Land application of MSW and SS compost is an effective waste disposal technique. However, However, MSW and SS compost often contains potentially toxic elements that can cause soil contamination, phytotoxicity and undesirable residues in plant and animal products. In order to avoid food chain, MSW and sewage sludge compost has often been utilized in green land (for example lawn), leading to heavy metal pollution in urban soil. Additionally, carbon-based nano-materials have great specific surface area and the structure of rich pores. After modification, carbon-based nano-materials have a lot of oxygen functional groups in surface with a strong adsorption of heavy metals. Therefore, by adding two modified carbon-based nano-materials- graphene and carbon black in compost and planting turfgrass in compost-amended soil, the objective of this research is going to investigate the kinetic mechanism of heavy metal adsorption and the effect of environmental release. Microscopic analytical technologies and culture experiments are applied to investigate compost heavy metal migration in soil-plant system, the kinetic mechanism of adsorption/desorption of heavy metals from available to residual state, the responses of soil properties, soil enzymes and ecological indicators of soil taxa to carbon-based nano-materials. The results of this study will provide scientific basis for safe application of compost products as well as heavy metal remediation.