污水处理厂尾水硝酸盐抑制水体黑臭反复的效果及机理研究

Effectiveness and mechanism of nitrate in wastewater plant tailwater to inhibit recurrent black-odorous rivers

防治河道返黑返臭是城市河道生态环境改善的关键,研究考察了污水处理厂尾水硝酸盐(NO_(3)^(-))对水体返黑返臭的影响,探究了在污水处理厂尾水NO_(3)^(-)作用下氮形态、硫形态的变化,解析了污水处理厂尾水NO_(3)^(-)抑制水体返黑返臭的机理。结果表明:污水处理厂尾水NO_(3)^(-)作用下上覆水DO和ORP得到明显提升;在第90天NH_(3)-N降低至0.9 mg/L;底泥AVS减少了45.5%,水体黑臭的潜在风险降低。利用扩增子测序分析发现污水处理厂尾水NO_(3)^(-)作用下沉积物中硫氧化菌Thiobacillus、Bosea、Nitrobacter及Pseudomonas的丰度明显增加,硫酸盐还原菌Desulfobacterium、Syntrophus的丰度显著降低。Sterolibacterium、Denitratisoma及Silanimonas等反硝化菌丰度也有所提升。

Preventing the return of black-odorous rivers is the key to improving the ecological environment of urban rivers.This study investigated the effect of nitrate(NO_(3)^(-))in the tailwater of wastewater treatment plants on the black-odorous return of the water body,explored the changes of nitrogen and sulfur under the action of NO_(3)^(-)in the tailwater of wastewater treatment plants,and analyzed the mechanism of the inhibition of the black-odorous return of the water body under the action of NO_(3)^(-)in the tailwater of wastewater treatment plant.The results showed that the DO and ORP of the overlying water were significantly enhanced by NO_(3)^(-) activated wastewater tail water,NH_(3)-N was reduced to 0.9mg/L on the 90th day,and the AVS of the substrate was reduced by 45.5%,which reduced the potential risk of black-odorous in the water body.Analysis using amplicon sequencing revealed a significant increase in the abundance of the sulfur-oxidizing bacteria Thiobacillus,Bosea,Nitrobacter and Pseudomonas and a significant decrease in the abundance of the sulfate-reducing bacteria Desulfobacterium and Syntrophus,in the sediment under the action of NO_(3)^(-)in the tailwater of the wastewater treatment plant.The abundance of denitrifying bacteria such as Sterolibacterium,Denitratisoma and Silanimonas also increased.