生物质腐殖化制备的有机质对水中有机污染物的非线性吸附机制及规律研究

Nonlinear sorption of organic compounds by soil organic matter (SOM) is an key distribution behavior between soils and water, controlling the fate, transfer, transport, bioavailability and eco-environmental risks of these organic contaminants. The nonlinear sorption behavior is governed by SOM characteristics and compound properties. SOM investigated in the most previous studies regarding sorption of organic contaminants were extracted from soils using base solution. These extracted SOM are very complex because they are the mixture originated from various biomass including plants and animal remains with different humification degrees, resulting in that the effects and mechanisms of SOM characteristics on nonlinear sorption is still unclear yet. Therefore, in this study, we will prepare organic matter with different humification degrees from single biomass such as straw, sawdust, bamboo chips, activated sludge, lignin, and cellulose under various hydrothermal conditions. We will identify the characteristics of these organic matter, and, investigate the sorption-desorption and competitive behaviors of PAHs, nitrobenzenes and phenols by these organic matter. With these experiments and the expected results, we hope to find correlations and effect mechanisms of SOM characteristics on nonlinear sorption for better understanding of the nonlinear sorption behavior of organic compounds by SOM. These information will be helpful for predicting the fate, transfer, transport, bioavailability and eco-environmental risks of organic contaminants in soil environment.

土壤有机质对有机物的非线性吸附行为是有机污染物在土壤中累积储存的主要机制，决定着它们在土壤环境中的迁移、转化及生物可利用性等环境归宿及生物生态效应。由于现有研究从土壤中通过碱提取的有机质是不同生物质前驱物在不同腐殖化条件和不同腐殖化程度下形成的混合物，其结构组成性质十分复杂，导致有机质结构组成性质对有机物非线性吸附的影响及机制方面的研究至今仍然没有明确的结论。因此，本项目拟用秸秆、木屑、竹屑、活性污泥、木质素、纤维素等生物质前驱体水热制备不同程度腐殖化的有机质，通过研究PAHs、硝基苯类、酚类等典型有机物在它们上的吸附-脱附行为及竞争吸附行为，分析生物质前驱体及腐殖化程度不同导致的有机质结构性质差异，从而探明有机质组成结构性质对有机物非线性吸附的影响及机制规律，提高人们对有机污染物非线性吸附行为本质的认识。研究结果将为预测评估有机污染物在环境中的迁移、转化、归宿和环境风险提供理论基础。

土壤有机质对有机物的非线性吸附行为是有机污染物在土壤中累积储存的主要机制，决定着它们在土壤环境中的迁移、转化及生物可利用性等环境归宿及生物生态效应。本项目研究了秸秆、木屑、竹屑、活性污泥、木质素、纤维素等生物质前驱体制备的不同程度腐殖化程度有机质对 PAHs、硝基苯类、酚类等20多种典型有机物的非线性吸附-脱附行为及竞争吸附行为，建立了非线性吸附容量及吸附作用力与有机质结构性质、有机污染物物理化学性质间的定量线性关系规律和预测模型，分析了有机质组成结构性质对有机物非线性吸附的影响及机制规律，并深入开展了模拟有机质非线性吸附研究和生物质制备生物炭非线性吸附的比较研究，证实了非线性分配是有机质对有机污染物非线性吸附的主导机制的观点，探明了非线性分配吸附机理特征，发展了非线性分配吸附理论体系，提高了学界对有机污染物非线性吸附行为本质的认识并丰富了吸附理论。此外，对非线性吸附理论及预测模型指导下的有机污染土壤修复技术开发和有机污染物环境迁移行为评估预测进行了探索研究。研究结果将有助于预测评估有机污染物在环境中的迁移、转化、分布、传输、生物可利用性、归宿和环境风险，并可为开发或选择有效的有机污染土壤修复技术提供理论基础，已发表SCI论文16篇，培养毕业博士生3人、硕士生6人，项目负责人2021年入选了国家万人计划科技创新领军人才。