生物炭负载稳定化δ-MnO2修复雌激素污染洞庭湖湿地表层沉积物的行为机理与微生物群落响应研究

With the rapid development of intensive livestock farming, Dongting Lake Wetland has been polluted by estrogens in various degrees at different levels. Carbonaceous materials such as biochar can be used as an important in-situ remediation technology to remediate organic polluted wetland via immobilization/stabilization. However, this process is just an enrichment method and cannot remove pollutants completely. It has been demonstrated that δ-MnO2 nanoparticle can effectively degrade organic pollutants such as estrogen. Thus, biochar loaded with δ-MnO2 may be a novel material to repair estrogen pollution in surface sediment, while the related mechanisms are unclear. Consequently, during the remediation of estrogens polluted surface sediment by stabilized δ-MnO2 loaded biochar, their remediation effects and mechanisms in the ecological toxicology, microenvironment and molecular levels will be researched. Main investigation contents include: Preparation, optimization and characterization of stabilized δ-MnO2 loaded biochar will be surveyed. We will study the procedure optimization and behavior mechanisms during the remediation of estrogens polluted surface sediment by stabilized δ-MnO2 loaded biochar. To illustrate the remediation effects, the bioavailability of contaminants during remediation procedure will also be investigated. Moreover, we will study the responses of microbial community structure, gene diversity and metabolic capacity to stabilized δ-MnO2 loaded biochar. All in all, this research will offer theoretical supports for the development of remediation technology for estrogens polluted surface sediment in wetland using stabilized δ-MnO2 loaded biochar.

集约化养殖业的快速发展导致洞庭湖湿地受到不同程度的雌激素污染。生物炭等碳质材料用于固定/稳定化湿地有机污染物是一类重要的原位修复方法，但其只能浓缩富集而不能从根本上去除污染物。目前已证实纳米δ-MnO2能有效降解雌激素等有机污染物，但利用生物炭负载稳定化δ-MnO2修复雌激素污染表层沉积物的有关机理尚不清楚。为此，本项目拟以湖南省东洞庭湖为对象，从生态毒理学、微环境和分子水平，综合揭示生物炭负载稳定化δ-MnO2修复雌激素污染表层沉积物的行为机理与微生物群落响应机制，包括：优化生物炭负载稳定化δ-MnO2的制备及表征；研究其修复雌激素污染表层沉积物的过程优化与行为机理；探讨表层沉积物中污染物的生物有效性变化；解析修复过程表层沉积物微生物群落结构、基因多样性和代谢功能的动态响应机制。本研究可为发展生物碳负载稳定化δ-MnO2修复雌激素污染湿地表层沉积物关键技术提供重要理论依据。

水体中有机物的长期污染对生态环境和人类健康造成严重损害，是亟待解决的问题。生物炭作为一种价格低廉的碳质材料已广泛应用于土壤改良和污染物处理，其作为吸附剂用于水体污染修复潜力巨大。本文主要研究了改性生物炭材料的制备方法，基本物理化学性质，及其在水体中有机物固定转化中的应用。采用化学改性方法对生物炭进行活化处理，通过化学沉降法将铁锰氧化物负载在生物炭表面，合成生物炭/镁铝水滑石复合材料，进一步提高生物炭对水体中有机物的固定转化能力。研究结果能为生物炭基材料用于水环境修复工程提供理论基础和实用指导。