不同氮浓度冲击对颗粒污泥脱氮过程中N2 O产生量的影响

采用好氧-缺氧SBR污水生物处理系统,考察不同进水NH4+-N浓度冲击对同步硝化反硝化型颗粒污泥脱氮过中N2O的释放规律和脱氮效果的影响.结果表明,当进水NH4+-N浓度分别从稳定的30 mg·L-1突然提高到40、60和80 mg·L-1时,氨氮去除率从80.04%降至61.40%、39.65%和31.02%,但氨氮的去除量变化不大,都在25 mg·L-1左右;另外,N2O产生量受进水NH4+-N冲击较小,在4个不同的进水NH4+-N浓度下,典型周期N2O产生量分别为3.019、3.489、3.271和3.490 mg·m-3,而且N2O释放速率都在0.004 5 mg·(m3·min)-1左右.同步硝化反硝化型颗粒污泥系统的好氧阶段和缺氧阶段均有N2O产生.不同的NH4+-N浓度冲击下,同步硝化反硝化型颗粒污泥系统对NH4+-N的去除量没有变化,但由于进水NH4+-N浓度的提高引起系统脱氮率显著下降.

Impact of Different Nitrogen Concentrations on the N2 O Production in the Denitrification Process of Granular Sludge

The aerobic-anoxic SBR biological wastewater treatment systems were used to examine the impact of different influent NH₄⁺-N concentrations on the release of N₂ O and nitrogen removal in the simultaneous nitrification and denitrification of granular sludge. The results showed that when the influent NH₄⁺-N concentration suddenly increased from the stable concentrations of 30 mg·L^-1 to 40 mg·L^-1,60 mg·L^-1 and 80 mg·L^-1, the ammonia removal rate decreased from 80.04% to 61.40%,39.65% and 31.02%, respectively, however, the ammonia nitrogen removal amount underwent little change, being about 25 mg·L^-1 in all cases; in addition, there was little influence of influent NH₄⁺-N on the N₂ O production, under the four different influent NH₄⁺-N concentrations, the N₂ O production in a typical cycle was 3.019 mg·m^-3, 3.489 mg·m^-3, 3.271 mg·m^-3, and 3.490 mg·m^-3, respectively, and the N₂ O emission rates were all around 0.0045 mg·(m³·min)^-1. N₂ O was produced in both the aerobic stage and anoxic stage of the granular sludge simultaneous nitrification and denitrification system. Under different influent NH₄⁺-N concentrations, the amount of NH₄⁺-N removal by the granular sludge simultaneous nitrification and denitrification system was not changed, but significant decrease in nitrogen removal rate was observed with the increase in the influent NH₄⁺-N concentration.