新型生物电化学系统高效处理垃圾渗滤液的机理研究

Waste leachate is the main secondary pollutant produced in the process of waste incineration and landfill. It can pose a serious threat to the ecological environment and human health. The harmless treatment and resource recovery of waste leachate are of great national needs and practical significance. Bioelectrochemical system, with a great potential for wastewater treatment, waste energy and resource recovery, is a new wastewater treatment technology developed in recent years. In this project, in order to solve the problems of low charge recovery rate, low charge utilization rate and energy reuse during the waste leachate treatment in bioelectrochemical system, a new DMDC (Dual stream microbial desalination cell) was developed. Meanwhile, the following mechanisms for simultaneous waste leachate high-efficient treatment and resource recovery will be investigated: (1) the enhanced degradation mechanism of organic pollutant of waste leachate in the DMDC system; (2) the transformation and transportation of organic pollutant, ammonia and typical heavy metal; (3) the relationship between removal process (such as redox process, electrodialysis removal and cathode accumulation) of ammonia/typical heavy metal and the degradation/energy production process of organic pollutant; (4) the performance enhancement strategies and mechanisms of the DMDC system, such as increasing the number of ions exchange chamber, applying external voltage and combining the electro-fenton system.

垃圾渗滤液是垃圾焚烧和填埋过程中产生的主要二次污染物，对生态环境和人体健康造成严重威胁，其无害化与资源化，具有重大的国家需求和现实意义。生物电化学系统是近年发展起来的新兴的废水处理技术，同时具有废水能量和资源回收的潜力。本项目主要针对生物电化学系统处理垃圾渗滤液过程中，电荷回收率低、电荷利用率低、产生能量无法有效利用的问题，构建了双流式微生物脱盐池生物电化学系统，研究垃圾渗滤液中典型有机污染物在系统中的生物、电化学协同强化降解机制；通过解析氨氮和典型重金属的迁移转化规律，探讨氨氮和重金属的氧化还原、电渗析脱除、阴极累积等过程与有机物降解产电过程之间的内在关系；并进一步通过增加离子交换室数目、提供外加电压、引入电芬顿旁路等方法，探求系统效能强化机制，为实现生物电化学系统对垃圾渗滤液的高效处理与资源化提供理论基础。

垃圾渗滤液是垃圾焚烧和填埋过程中产生的主要二次污染物，对生态环境和人体健康造成严重威胁，其无害化与资源化具有重大的国家需求和现实意义。生物电化学系统是近年发展起来的新兴的废水处理技术，同时具有废水能量和资源回收的潜力。课题组在三年的执行期内：构建了双流式微生物脱盐池（DMDC）生物电化学系统，并通过提高阴极液pH、外加电压、提高阴极液曝气强度等方法实现系统的强化，可使垃圾渗滤液COD下降70%以上、氨氮的去除率和回收率达50%和20%以上，重金属去除率达70%以上；探讨了DMDC系统中电场促进有机离子定向移动的有机污染物生物与电化学协同强化降解机制；揭示了DMDC系统中氨氮的阳极生物硝化反硝化、阴阳极的离子交换膜分离作用、氨氮的扩散、电荷移动、氨氮转化和氨氮吹脱等高效脱除与回收的机理机制；解析了DMDC系统中重金属的阳极生物吸附、生物吸收、离子交换等高效脱除机制；明确了产电对铵根离子定向转移、游离氨转化等作用，以及氨氮脱除对有机物降解产电的弱促进作用；进一步研发了堆叠式电芬顿技术，以解决DMDC系统处理后垃圾渗滤液的后续处理问题。该研究为实现生物电化学系统对垃圾渗滤液的高效处理与资源化提供理论基础。