生物产电加速厌氧堆肥污泥降解及产电性能

Performance of sludge degradation and electricity production accelerated by bioelectrogenesis in sludge anaerobic composting

为解决污泥厌氧堆肥系统(AnC)运行周期长的问题,在AnC中设置电极引入生物产电技术加速污泥降解同时实现电能回收,构建微生物燃料电池(MFC)型厌氧堆肥系统(MFC-AnC),考查MFC-AnC对污泥降解及产电性能.结果表明,以脱水污泥为堆肥底物、铁氰化钾为阴极电解液的MFC-AnC堆肥45d后污泥有机质去除率达22.4%,对照组AnC中为17.7%.MFC-AnC开路电压可达0.84V,最大功率密度为5.3W/m3,内阻为98Ω.增大污泥含水率可显著降低MFC-AnC内阻,提高产电性能.餐厨垃圾的添加可改善脱水污泥降解特性,促进厌氧堆肥顺利进行,降低MFC-AnC内阻.当餐厨垃圾∶脱水污泥体积比为0.5∶1时,获得系统最低内阻和最高输出电压,继续增大餐厨垃圾比例将使内阻升高.

In order to solve the problem of long operation period in anaerobic composting system, an MFC- AnC system was constructed by introducing bioelectrogenesis into AnC system to enhance the sludge degradation and recovery power simultaneously. The performance of sludge degradation and electricity generation was investigated. After 45 days composting, the organic matter w （OM） removal efficiency of dewatered sludge in AnC was 17.7%, while in MFC-AnC achieved 22.4% and the maximum power density was 5.3 W/m^3 , the open circuit potential （OCP） was 0.84V and the internal resistance was 98 ohm with potassium ferricyanide as its electron acceptor. Increasing the moisture content （MC） of the raw dewatered sludge can significantly reduce the internal resistance of MFC-AnC and enhance the electricity generation. Adding food waste in the raw dewatered sludge can improve the performance of sludge degradation and reduce system internal resistance. The lowest internal resistance and the highest voltage output of MFC-AnC were obtained when the ratio of food waste, dewatered sludge was 0.5 ：1. Improving the food waste proportion more than that would increase the internal resistance.