载铁生物炭强化人工湿地中多环芳烃去除机制的研究

In recent years, polycyclic aromatic hydrocarbons (PAHs) are extremely harmful to the ecological environment and human health, and has been widely studied. Although the constructed wetland (CW) has been employed increasingly in PAHs removal, there are still two technical problems of insufficient dissolved oxygen and low efficiency of microbial degradation. Based on the special dissolved oxygen environment of constructed wetlands, this project utilize iron-loaded biochar to enhance the removal capacity of PAHs by the CW according to the adsorptive capacity of biochar, as well as the exogenous electron acceptor provided by iron for microbial degradation of PAHs. Use wetland plants to produce new iron-loaded biochar, and construct iron biochar-enhanced CW systems. Explore the transformation of PAHs in CW system and the iron cycle influenced by FeRB . And analyze the effects of iron biochar on microbial degradation of PAHs. The long-term stable operation of new CW under complex conditions was systematically evaluated. the economic feasibility and scalability of the CW were also studied. The development of this research will provide a scientific basis for controlling the PAHs pollution in water and promoting the water purification technology of CW.

近年来，有关水体中多环芳烃（PAHs）污染的研究逐渐增多，PAHs对生态环境和人类健康危害极大。采用人工湿地技术去除PAHs虽取得一定的成效，但是仍存在基质吸附能力不足和微生物降解效率低两大技术难题。本项目基于人工湿地特殊的溶解氧环境，充分利用生物炭的截留和吸附能力以及铁离子作为微生物降解PAHs的外源电子受体，提出了载铁生物炭强化人工湿地去除PAHs的解决方案。资源化利用湿地植物研发新型载铁生物炭填料，构建并优化载铁生物炭人工湿地系统；探究PAHs在人工湿地系统的迁移转化规律，结合铁氧化及异化还原菌介导的铁循环规律，分析载铁生物炭对微生物降解机制的影响，掌握系统中铁离子氧化还原对PAHs降解的内在规律；系统评价载铁生物炭人工湿地在复杂条件下的长期稳定运行能力，评估本项目成果的经济可行性及可推广性。本研究工作的开展，将为控制水体PAHs污染、推广人工湿地净水技术提供科学依据。

项目破解了人工湿地处理PAHs存在的基质吸附能力差和微生物降解效率低的两大难题，资源化利用湿地废弃植物制备生物炭，通过水热法负载氧化铁合成载铁生物炭填料，系统评估了载铁生物炭理化性质及对PAHs吸附降解性能，为载铁生物炭作为基质填料提供理论依据；构建了载铁生物炭垂直流人工湿地污水生态处理系统，探究了系统中溶解氧分布规律，分析了氧传质与PAHs降解之间的动态响应关系，比较了填料不同投加量对PAHs去除的影响，优化了人工湿地系统工艺运行条件；分析了进水中PAHs的分配过程和流向，揭示了人工湿地系统中PAHs的降解及归趋途径，探究了人工湿地系统中PAHs的物质、能量流向与空间分布特征，量化了人工湿地系统中植物吸收、基质吸附、微生物降解等路径的贡献，掌握了基质中铁的价态转换及铁循环对PAHs转化路径的影响，明确人工湿地系统中PAHs的迁移转化规律；采用现代分子生物学技术，解析了投加载铁生物炭填料后人工湿地中微生物的群落结构、数量、活性的响应规律，分析了系统中铁氧化物的结构和表面化学成分，研究了系统中PAHs和一般污染物的浓度变化关系，揭示了人工湿地系统中微生物对PAHs降解机制，掌握了基质吸附、铁循环、微生物降解三者的关系。相关研究成果共计发表SCI论文14篇，申请/授权发明专利8项，参加国内外学术会议3次，培养研究生4名，其中1名研究生获得山东大学校长奖（山东大学学生最高荣誉）。