高浓度氨氮消化污泥脱水液半短程硝化试验研究

采用A/O工艺考察了消化污泥脱水液半短程硝化及维持的影响因素和控制方法.结果表明，在温度9～20℃、平均DO浓度5.4 mg/L、SRT 30 d左右时，进水氨氮负荷（以N计，下同）0.64 kg/(m³·d)的条件下启动，经过29 d实现了短程硝化，此后的65 d内，动态控制反应器游离氨FA>4 mg/L时，70%亚硝氮累积率的短程硝化得以维持；在实现短程硝化的基础上，进而实现了半短程硝化，出水氨氮与亚硝氮浓度比维持在1∶1.32左右；当氨氮负荷降至0.19 kg/(m³·d)时(FA<1 mg/L)，短程遭到破坏，在不同FA下取样做FISH分析，进一步证明了高FA是维持半短程硝化的主要因素；在进水中COD为282 mg/L， C/N仅为0.85的条件下，由于实现了短程硝化，系统TN去除量约为91 mg/L.结果分析表明，消化污泥脱水液在中低温、高DO浓度、长SRT下，通过动态控制氨氮负荷和pH值等运行参数，在系统中维持适宜的FA浓度(>4 mg/L)，可以实现并维持半短程硝化，为后续的厌氧氨氧化提供进水或回流到污水厂主流区而节省反硝化碳源.

Half-nitrosofication of Dewatering Liquid of Digested Sludge with High Ammonia

The affecting factors and controlling methods of how realizing and maintaining half-nitrosofication of dewatering liquid of digested sludge were investigated in an A/O process. The experimental results showed that the nitritation was obtained in 29 d under bulk liquid temperature of 9-20℃,average DO of 5.4 mg/L,SRT of about 30 d and influent ammonia loading rate of 0.64 kg/(m3·d). The nitritation with 70% nitrite accumulation efficiency was maintained during 65 d when average FA concentration in A/O reactor was more than 4 mg/L. Furthermore,the half-nitrosofication with effluent ammonia and nitrite ratio of 1∶1.32 was obtained. When the ammonia loading rate reduced to 0.19 kg/(m3·d) (FA<1 mg/L),the nitritation disappeared,and the high FA as a main factor of maintaining half-nitrosofication was proved again with FISH under the condition of different FA. TN removal concentration was about 91 mg/L under influent COD of 282 mg/L and raw C/N ratio of 0.85 in the A/O system,which due to nitritation saving much carbon sources. The study showed that the half-nitrosofication of the dewatering liquid was obtained and stably maintained when FA was more than 4 mg/L in the A/O reactor by dynamic controlling influent ammonia loading rate and pH value in the system under middle or low temperature,high DO,long SRT.