聚噻吩改性阴极强化电极生物膜反应器去除硝酸盐机制研究

为进一步提高电极生物膜反应器的脱氮效能,采用导电聚合物聚噻吩(PTh)和电子穿梭体蒽醌-2,6-二磺酸二钠(AQDS)改性阴极材料石墨毡,系统研究了不同碳氮比(C/N)条件下,改性电极的应用对BER体系的脱氮效能、电极表面生物相和体系微生物群落结构等方面的影响.结果表明,应用PTh与AQDS协同处理石墨毡的BER体系的NO~-_3-N去除速率和效能均明显优于未处理电极体系,在HRT=4 h、C/N为2.0时NO~-_3-N的去除率达到90.0%以上.PTh/AQDS改性石墨毡电极的生物膜与电极的比重为0.26±0.04,其值为对照组的2.4倍,证明了PTh/AQDS改性后电极具有更优的生物相容性.应用PTh/AQDS改性电极的BER具有更好的微生物丰富度和多样性,AQDS促进了特定微生物Thauera_mechernichensis(24.6%)的富集和亚硝酸盐还原酶的活性,保障了BER体系的反硝化效能.

Cathode modified by polythiophene to enhance the nitrate removal in biofilm electrode reactor(BER)

In order to improve the denitrification efficiency of the BER, conductive polymer polythiophene (PTh) and electronic shuttle anthraquinone-2, 6-disulfonate disodium (AQDS) were used to modify graphite felt. The effects of modified electrode on denitrification performance, biological phase of electrode surface and microbial community structure of BER systems were systematically investigated under different C/N conditions. The experimental results showed that the denitrification perfoemance in BER system with PTh/AQDS modified graphite felt was much better than the control BER and the nitrate removal efficiency was higher than 90.0% as C/N was 2.0.The ratio of biofilm to electrode of PTh/AQDS modified graphite felt electrode was 0.26±0.04, 2.4 times higher than that of the control group, which proved that PTh/AQDS modified electrode had better biocompatibility. The proportions of biofilm and electrode of PTh/AQDS modified graphite felt cathode was 0.26±0.04, which was 2.4 times higher than unmodified electrode''s. This demonstrated that PTh/AQDS modified graphite felt has better biocompatibility.The BER with PTh/AQDS modified electrode showed better microbial richness and diversity. Furthermore, AQDS addition was in favor of Thauera_mechernichensis (24.6%) enrichment and nitrite reductase activity, which contribute to the higher denitrification efficiency of BER system.