基于固体碳源反硝化的低碳源污水生物硝化技术

Novel Technology of Low-carbon Wastewater Biological Nitrification Based on Solid Carbon Denitrification

在污水处理工艺末端嵌入固体碳源反硝化滤池,可以不改变污水处理厂的原有工艺并提高对总氮的去除效率,方便应对污水厂的提标压力和低碳源污水的脱氮问题。以序批式生物膜反应器(SBBR)为对象,探究有利于低碳源污水生物硝化的运行模式和固体碳源反硝化滤池的脱氮效果。结果表明:对于COD为93~140 mg/L、TN为41~45 mg/L的低碳源污水,在SRT为20d、充水比为0.4、周期时间为3 h、氨氮负荷为0.112 kg/(m^3·d)、曝气量为3.8 m^3/(h·m^3)的情况下,SBBR的出水氨氮为1.5 mg/L,出水硝态氮为16 mg/L,出水硝态氮占出水总氮的70%,实现了高效稳定硝化。富含硝态氮的SBBR反应器出水通过固体碳源反硝化滤池后,出水总氮平均值为4.23 mg/L,COD平均值为25 mg/L,均低于《城镇污水处理厂污染物排放标准》(GB 18918—2002)的一级A标准,系统总的脱氮率大于90%,获得了优异的低碳源污水生物脱氮效果。

Embedding the solid carbon denitrification biofilter （SCDNBF） at the end of the wastewater treatment process could improve the total nitrogen removal efficiency without changing the original process of the wastewater treatment plant, and conveniently deal with the pressure of the reconstruction of wastewater treatment plant for upgrading, as well as the difficulty in nitrogen removal of the low- carbon wastewater. The running mode of sequencing batch biofilm reactor （SBBR） for low-carbon wastewater biological nitrification and the nitrogen removal efficiency of the SCDNBF were investigated. The results showed that when the iniluent COD and TN concentrations were 93 to 140 mg/L and 41 to 45 mg/L respectively and the operating conditions of SBBR were SRT of 20 d, water filling ratio of 0.4, cycle time of 3 h, ammonia loading rate of 0.112 kg/（ m^3 ·d） and aeration rate of 3.8 m^3/（ h· m^3 ）, the effluent NH3 -N and nitrate nitrogen concentrations were 1.5 mg/L and 16 mg/L respe^tively, and the nitrate nitrogen accounted for 70% of the TN, achieving a stable and efficient nitrification. The nitrated effluent of SBBR was denitrificated by the SCDNBF, the average total nitrogen and COD concentrations in the effluent were 4.23 mg/L and 25 mg/L respectively, both were below the first level A criteria specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant （GB 18918 - 2002 ）. The nitrogen removal efficiency of the SBBR - SCDNBF system could exceed 90%, achieving excellent biological nitrogen removal effect of low-carbon wastewater.