Abstract:
Septic tanks are widely adopted in decentralized household wastewater treatment systems serving billions of people globally. Due to the lack of effective electron acceptors, insufficient nutrient removal and the emission of harmful gases, e. g. H2S, CH4, etc., are the common drawbacks. In the present work, we attempted to supplement nitrite into septic tanks as an electron acceptor, via nitrifying human urine source-separated from blackwater, to overcome these drawbacks. Partial or complete nitritation of source-separated urine was achieved in a sequencing batch reactor. The addition of nitrified urine into septic tanks improved organic and nitrogen removals in blackwater up to 90 % and 70 %, respectively. The emission of harmful gases from the septic tanks was stably diminished, with more than 75 % of CH4, CO2 and H2S reductions. Nitrite addition significantly reduced the abundance of hydrogenotrophic methanogens in septic tanks. Though the activity of sulfate-reducing bacteria recovered after the initial inhibition upon nitrite addition, the bio-generated H2S was retained in water since the increased wastewater pH after nitrite addition promoted the disassociation of H2S in aqueous solution.
摘要:
化粪池广泛用于分散的家庭污水处理系统,为全球数十亿人提供服务。由于缺乏有效的电子受体,营养去除不足和有害气体的排放,H2S,CH4等,是常见的缺点。在目前的工作中,我们试图在化粪池中补充亚硝酸盐作为电子受体,通过从黑水中分离的人尿液来源的硝化,克服这些缺点。在序批式反应器中实现了来源分离的尿液的部分或完全亚硝化。在化粪池中添加硝化尿液可提高黑水中有机和氮的去除率达90%和70%,分别。化粪池有害气体排放稳定减少,减少超过75%的CH4、CO2和H2S。亚硝酸盐的添加显着降低了化粪池中氢营养型产甲烷菌的丰度。虽然硫酸盐还原细菌的活性在亚硝酸盐添加的初始抑制后恢复,生物产生的H2S保留在水中,因为亚硝酸盐添加后废水pH值的增加促进了H2S在水溶液中的解离。