硫自养反硝化深度处理污水厂生化出水中的NO_(3)^(-)-N

Sulfur Autotrophic Denitrification for Advanced Treatment of NO_(3)^(-)-N in Effluent from Biochemical Treatment Process of Wastewater Treatment Plant

针对呼和浩特市某污水处理厂A^(2)O工艺出水中残余的NO_(3)^(-)-N,利用生物滤池进行单质硫自养反硝化中试研究。结果表明,单质硫自养反硝化工艺启动周期短(15 d)、去除NO_(3)^(-)-N能力强,NO_(3)^(-)-N去除负荷(以N计)基本可保持在200 g/(m^(3)·d)以上。在启动过程中,Thiobacillus逐渐成为优势菌属,硫自养反硝化反应成为了生物滤池的主要代谢路径。此外,水温对该工艺性能有一定影响,当水温<15℃时生物滤池内的微生物群落结构会受到一定影响,平均NO_(3)^(-)-N去除负荷迅速降至122.7 g/(m^(3)·d),即使延长水力停留时间,系统亦无法恢复至最佳状态。

A pilot scale test of elemental sulfur autotrophic denitrification in the biofilter was carried out to remove the residual NO_(3)^(-)-N in the effluent from A^(2)O process of a wastewater treatment plant(WWTP)in Hohhot.Elemental sulfur autotrophic denitrification process had a short start-up period(15days)and a strong NO_(3)^(-)-N removal capacity.The NO_(3)^(-)-N removal load(calculated by nitrogen)could remain above 200 g/(m^(3)·d).During the start-up process,Thiobacillus gradually became the dominant bacterium,and sulfur autotrophic denitrification became the main metabolic pathway of the biofilter.In addition,water temperature had a certain impact on the performance of the process.When the water temperature was less than 15℃,the microbial community composition in the biofilter was affected to a certain extent,and the average NO_(3)^(-)-N removal load decreased rapidly to 122.7 g/(m^(3)·d).Even if the hydraulic retention time was extended,the system could not recover to the optimal state.