污泥农用的土壤生物风险及调控原理研究

Large quantities of sewage sludge are produced due to the rapid development of urbanization and the increasing amount of wastewater treated. Safe disposal of large amounts of sewage sludge is urgently required. However, there has been no systematic investigation in China on the distribution or spatial and temporal variation and ecological effects of pollutants in sewage sludge. Few studies have been done focuseing on the risk assessment for soil biology and the factors affecting sewage sludge-amended soils. Based on the investigation of the distribution of pollutants (antibiotics, antibiotic resistance genes, organic pollutants and heavy metals) in the sewage sludges of provincial cities, according to sludge composition and disposal methods, this program aims to determine the effects of sludge application on: (i) the translocation and availability of pollutants in soil profiles and the relationships with soil physic-chemical properties; (ii) soil microbial diversity and functions; and (iii) plant growth and the behaviour of rhizosphere microorganisms. The purpose is to evaluate the biological risk of sewage sludge amended soils, adaptative mechanisms of plants and microbes exposed to high concentrations of pollutants in the soil environment after sludge application, and to reveal biological control measures and remediation principles that can be developed to help ensure the safety, efficient disposal and resourceful use of sewage sludges.

随着我国城市化和污水处理率的提高，污水污泥处置已成为亟待解决的突出环境问题。目前，我国对污水污泥中污染物的分布特征、时空变异规律与生态效应等尚缺乏系统调查，在污泥土地利用的土壤生物风险及评价、污泥农用土壤污染的调控原理等方面也鲜有研究。本项目拟针对我国污泥农用可能导致的土壤生物污染问题，在调查国内主要城市污水污泥中抗生素、抗性基因、有机污染物及重金属等污染物分布特点的基础上，根据污泥的污染物特征、暴露途径和危害方式，研究污泥土地利用后污染物的迁移、转化、有效性及其与土壤性质的关系，污泥中污染物对生物多样性及生物功能的影响，污泥大量/长期农用对植物生长和根际微生物特性的影响。以期探明污泥农用的土壤生物风险及农用后高污染环境下植物、微生物的适应机制，揭示污泥农用型土壤污染的生物调控与修复原理，为污泥资源化利用、安全利用提供理论依据。

随着我国城市化和污水处理率的提高，污水污泥处置已成为亟待解决的突出环境问题。项目针对我国污泥农用可能导致的环境问题，探明了我国主要城市污泥的重金属、抗生素等污染物分布与含量状况；通过盆栽和田间试验，探明了污泥连续农用下土壤重金属和抗生素的积累和消减规律、重金属的形态分布及食物链风险、对土壤微生物群落结构的影响；明确了抗生素在不同土壤上的吸附特征及主控因子；针对长期施用污泥导致锌镉污染土壤，开展了植物修复效应研究，探讨了污泥农用土壤污染的生物调控修复原理；为污染资源化和安全利用提供理论依据。