内电解-沉水植物-微生物耦合体系处理黑臭水体效能及机制研究

Study on treatment efficiency and mechanism of black-odorous water by coupling system of internal electrolysis-submerged plant-microbe

采用内电解-沉水植物-微生物耦合的方法进行黑臭水体原位生态修复效能的单因素影响研究,考察了苦草种植密度和铁碳填料用量对耦合体系除污复氧的影响,并对耦合体系协同作用机理进行了分析。结果表明,耦合体系具有良好的除污复氧能力,最佳苦草种植密度和铁碳填料用量分别为143株/m^(2)和20 g/L,此条件下运行25 d的溶解氧(DO)、氨氮转化率以及化学需氧量(COD)、总氮(TN)和总磷(TP)的去除率分别为3.87 mg/L、91.09%、79.30%、84.31%和98.40%。苦草根际微生物群落分析结果显示,耦合体系运行稳定后,优势菌为兼有自养和异养反硝化及聚磷作用的Pseudomonas,反硝化作用的Chryseobacterium,具有脱氮作用的Delftia和unclassified_f_Comamonadaceae,表明耦合体系具有自养反硝化能力,这与试验结果的计算分析相一致;具有降解有机物作用的Sphingomonadaceae和Nitrosomonadaceae的丰度都大于系统启动初期,Nitrosomonadaceae是试验过程中亚硝态氮积累的主要原因,表明耦合体系存在短程硝化反硝化脱氮过程。

The single factor effect on in-situ ecological restoration of black-odorous water was studied by the coupling system of internal electrolysis-submerged plant-microbe.The effects of the Vallisneria natans planting density and the dosage of iron-carbon filler on decontamination and reaeration of the coupling system were studied,and the synergistic mechanism of the coupling system was analyzed.The experimental results showed that the coupling system had good ability of decontamination and reaeration.The optimum Vallisneria natans planting density and iron carbon filler dosage were 143 stems/m^(2) and 20 g/L,respectively.The DO,ammonia conversion rate and the removal rates of COD,TN and TP were 3.87 mg/L,91.09%,79.30%,84.31%and 98.40%,respectively,when the coupling system was operated for 25 days.The results of microbial community analysis in the rhizosphere of Vallisneria natans showed that the dominant bacteria at the genus level were Pseudomonas with autotrophic and heterotrophic denitrification and phosphorus accumulation efficiency,denitrifying bacteria Chryseobacterium,Delftia and unclassified_f_Comamonadaceae.The results showed that the coupling system had the ability of autotrophic denitrification,which was consistent with the calculation analysis of the experimental results.At the family level,the abundance of Sphingomonadaceae and Nitrosomonadaceae was greater than that at the initial stage of test startup.Sphingomonadaceae has the ability to utilize a wide range of organic compounds.Nitrosomonadaceae was the main reason for nitrite accumulation during the experiment,which indicated that there was a short-cut nitrification and denitrification process in the coupling system.