铁碳内电解耦合蕹菜(Ipomoea aquatica)对黑臭污水脱氮效果的研究

构建了铁碳内电解耦合蕹菜技术体系，用于原位净化河道黑臭污水，采用单因素模拟实验，探究耦合体系植株密度、铁碳填料用量和陶粒用量对黑臭污水脱氮效果的影响规律.结果表明，在植株密度为80株/m2、铁碳填料用量为18 g/L和陶粒用量为52 g/L的适宜组合下，处理22 d后，TN和NH₄+-N的去除率分别为74.1%和99.6%，其质量浓度分别稳定在(13.65±1.24) mg/L和(0.18±0.04) mg/L.水体微生物丰度和多样性有了显著提高，主要优势细菌门是Proteobacteria、Firmicutes和Bacteroidetes，主要优势细菌属为Pseudomonas、Escherichia-Shigella和Diaphorobacter，微生物群落演化更适宜脱氮.耦合体系通过协同作用净化水质，其作用过程包括:铁碳内电解产生质子H]和Fe2+提供电子促进自养反硝化、蕹菜根际泌氧促进微生物硝化、陶粒生物膜与根际微生物之间的硝化反硝化作用、陶粒吸附氮.该研究为采用铁碳内电解耦合挺水植物净化河道黑臭污水提供了依据.

Effects of Nitrogen Removal in Black and Odorous Water Using Iron-Carbon Interior Electrolysis Combined with Ipomoea Aquatica

Iron-carbon interior electrolysis combined with Ipomoea aquatica was established to treat black and odorous water. The single factor experiment was adopted through variable-controlling to study the effects of different planting density, dosage of iron-carbon, dosage of ceramsite on denitrification. After 22 days, the removal rates of TN and NH₄+-N were 74.1% and 99.6% respectively and their contents were stabilized below (13.65±1.24) mg/L and (0.18±0.04) mg/L respectively under the suitable conditions of the planting density at 80 plants/m2, the dosage of iron-carbon at 18 g/L and the dosage of ceramsite at 52 g/L. Besides the abundance and the diversity of microoganisms were increased, the dominant bacterial phyla being Proteobacteria, Firmicutes and Bacteroidetes and the dominant bacterial genera being Pseudomonas, Escherichia-Shigella and Diaphorobacter, enabling the microbial community to be more suitable for the removal of nitrogen. The synergistic mechanism of the coupled system included: iron-carbon interior electrolysis could generate H] and Fe2+ as electron donor of autotrophic denitrification, radial oxygen loss in Ipomoea aquatica could promote the nitration reaction, biofilm of ceramic and rhizospheric microorganism could denitrify, and ceramsite could absorb nutrient. This study provided the basis for the treatment of black and odorous water with iron-carbon interior electrolysis combined with Ipomoea aquatica.