不同碳源对颗粒污泥反硝化过程中N2O产生量的影响

在好氧颗粒污泥系统稳定运行的基础上,考察不同碳源变化对好氧颗粒污泥脱氮过程的N2O的释放量和脱氮效果的影响。当以甲醇作为碳源,在整个缺氧过程中随着氨氮、亚硝酸盐、硝酸盐浓度的降低,系统中的N2O浓度也随之下降,反硝化过程中N2O浓度最高值为0.42mg/L,在缺氧条件下甲醇作为外部碳源所产生溶解态的N2O浓度最高为0.082mg/L。以乙醇作为投加碳源,当好氧结束时,释放气体中N2O浓度为1.21mg/L,在整个缺氧过程中N2O浓度逐渐下降,产生的N2O浓度最高值为0.87 mg/L,同时所产生溶解态的N2O浓度最高仅为0.077 mg/L。结果表明,在反硝化过程中向系统投加的作为外部碳源的甲醇与乙醇在充足的情况下,均能在好氧颗粒污泥反硝化过程中检测到有N2O生成,但是N2O生成量很小,可以忽略不计。因此,投加不同的碳源对好氧颗粒污泥反硝化过程中N2O生成影响不大。

Effect of Different Carbon Sources on Amount of N2O Emission from Denitrification Process of Granular Sludge

Based on stable operation of aerobic granular sludge system,the effect of different carbon sources on the process of aerobic granular sludge denitrification and the amount of N2O emission was studied.When methanol was taken as the carbon source,with the decrease of hypoxia ammonia,nitrite and nitrate concentrations,the concentration of N2O was also decreased in the whole process.During denitrification process,the highest concentration of N2O was 0.42mg/L.Under hypoxic conditions,the highest concentration of dissolved N2O produced by methanol as external carbon source was up to 0.082 mg / L.Adding ethanol as the carbon source,the concentration of N2O in its gas release was 1.21mg / L when the aerobic end.N2O decreased in the whole oxygen concentration process,and the highest value of the produced N2O was 0.87 mg / L,with highest dissolved N2O of 0.077 mg / L.Results show that,with adequate methanol and ethanol added into the denitrification process of aerobic granular sludge,the generation of N2O can be detected,but the amount is quite small that can be ignored.Therefore,adding different carbon sources into denitrification process of aerobic granular sludge has little effect on N2O generation.