双重抑制下亚硝化系统的启动及运行特性

Start-up and operating performance of nitritation system with dual inhibition

采用连续进水(feed-batch)方式的SBR在高氨氮负荷(1 kg·(m^3·d)^(-1))和双重抑制下实现了亚硝化系统的启动及稳定运行。采用荧光原位杂交技术(FISH)对活性污泥中氨氧化菌(AOB)和亚硝酸盐氧化菌(NOB)种群及数量变化进行测定。结果表明在温度(35±1)℃,进水氨氮浓度为1000mg·L^(-1)的条件下对NOB的抑制由游离亚硝酸(FNA)和DO的双重抑制转变为游离氨(FA)和DO的双重抑制,污泥亚硝酸盐氧化速率由28.16mg·(g·h)(以MLVSS计)降到0.3 mg·(g·h)^(-1)(以MLVSS计)以下,成功实现了高氨氮废水的稳定亚硝化。反应器出水NO_2^--N平均浓度为466.45 mg·L^(-1),NO_2^--N/NH_4^+-N接近1,NO_3^--N浓度低于20 mg·L^(-1),満足厌氧氨氧化(ANAMM0X)的进水基质要求。FISH结果表明,富集培养阶段AOB、NOB的优势种属由亚硝化单胞菌属(Nitrosomonas)及硝化螺旋菌属(Nitrospira)转变为Nitrosomonas及硝化杆菌属(Nitrobacter),抑制过程中NOB逐渐被淘汰最终硝化菌以Nitrosomonas为主,从微生物学角度佐证了亚硝化的稳定运行。

Partial nitrification was achieved and maintained stably under high ammonia loading（1 kg·（m^3·d）^-1） and dual inhibition in a SBR with feed-batch.The quantities and communities of ammonium oxidizing bacteria（AOB） and nitrite oxidizing bacteria（NOB） were detected using fluorescence in situ hybridization（FISH）.The results of the experiment showed that the inhibition of NOB changed from the dual inhibition of FNA and DO to FA and DO in the partial nitrification process at（35 ± 1）℃,with an ammonia concentration of1 000 mg·L^-1.The nitrite oxidizing rate reduced from 28.16 mg·（g·h）^-1（calculated by MLVSS） to 0.3 mg·（g·h）^-1（calculated by MLVSS）.The average effluent NO2^--N concentration and effluent NO2^--N/NH4^＋-N ratio were about 466.45 mg·L^-1 and 1,respectively.The effluent NO3^--N concentration was lower than20 mg·L^-1,which was suitable for use as the influent for ANAMMOX.The FISH results indicated that the dominating bacteria of AOB and NOB switched from Nitrosomonas and Nitrospira to Nitrosomonas and Nitrobacter in the enrichment phase.During the inhibition period,VOB was eliminated gradually,while Nitrosomonas dominated the system,which clearly indicates stable partial nitrification from the point of microbiology.