Electrochemical biofilter enhances performance of volatile organic compounds abatement

An electrochemical biofilter (EBF) was developed for enhancing the removal of volatile organic compounds (VOCs) through current. The removal efficiency (RE) of toluene exhibited a notable increase of 15% while the biomass growth rate exhibited a corresponding decline of 46% under an optimal current intensity of 50 mA. Meanwhile, the efficacy of the EBF system was markedly enhanced upon the removal of n-hexane, styrene, dichloromethane, and diisobutylene. The results indicated that there was an 11% to 49% increase in RE and a 0% to 64% reduction in biomass growth rates under the influence of the current. The current stimulation inhibited the accumulation of microorganisms, thereby alleviating biofilm clogging. The relative abundance of gram-positive phyla, including Firmicutes and Actinobacteria, increased by 15% and 23%, respectively, while the traditionally dominant genera within the Proteobacteria phylum, such as Rhodococcus and Dokdonella, exhibited a decline. In addition, the presence of hydrogen peroxide, free chlorine, and superoxides in the leachate indicated that the oxidative reaction increased in EBF system. This study provides an attractive pathway for current stimulation to enhance degradation of VOCs and alleviate biofilm clogging.

本研究开发了一种电化学生物滤池（EBF），用于通过施加电流强化挥发性有机物（VOCs）的去除效果。在最优电流强度为50 mA的条件下，甲苯的去除效率（RE）显著提升15%，而微生物生长速率则相应下降46%。与此同时，该EBF系统对正己烷、苯乙烯、二氯甲烷及二异丁烯的去除效能得到显著增强。研究结果表明，在电流作用下，目标污染物的去除效率可提升11%~49%，微生物生长速率则降低0%~64%。电流刺激可抑制微生物的增殖，从而缓解生物膜堵塞问题。厚壁菌门（Firmicutes）与放线菌门（Actinobacteria）等革兰氏阳性菌的相对丰度分别提升15%和23%；而变形菌门（Proteobacteria）内的传统优势菌属，如红球菌属（Rhodococcus）和Dokdonella属，其相对丰度则出现下降。此外，渗滤液中检出过氧化氢、游离氯与超氧化物，表明EBF系统内的氧化反应有所增强。本研究为通过电流刺激强化VOCs降解、缓解生物膜堵塞提供了一条极具应用前景的技术路径。