硝化微颗粒污泥的快速培养及其对硫化物的响应特性

Rapid cultivation of nitrifying microgranular sludge and its response to sulfides

在连续流气提内循环反应器中接种城市污水厂脱水污泥,考察硝化颗粒污泥快速培养及其对硫化物的响应特性.结果表明,在高接种污泥浓度(19.3g/L)条件下,通过逐步缩短HRT(7h降至2h)和提升进水氨氮负荷(0.5kg/(m^(3)·d)升至3.1kg/(m^(3)·d)),30d内基本实现污泥颗粒化,SVI3=SVI30为(16.8±0.3)mL/g,颗粒污泥平均粒径266μm;高浓度硝化颗粒污泥[(11.9±0.2)g/L]保证了系统的高负荷运行(氨氮去除负荷(2.4±0.3)kg/(m^(3)·d)).硫化物对颗粒污泥中氨氧化细菌(AOB)和亚硝酸盐氧化细菌(NOB)均有明显抑制,但AOB活性恢复明显快于NOB,硝化微颗粒污泥实现亚硝化功能,当硫化物浓度升至10mg/L时,亚硝化率达80%左右;然而,进一步提高硫化物浓度至20mg/L,亚硝化率无显著提升;第82d时的批次实验表明,AOB活性随初始硫化物浓度的升高而降低,NOB活性却呈上升趋势,推测与颗粒污泥中AOB(外层)和NOB(内层)的分层分布密切相关.此外,硫化物对小粒径(<0.3mm)硝化颗粒污泥的影响更为显著.

The dewatered sludge of municipal wastewater treatment plant was inoculated in a continuous flow gas lift internal circulation reactor,and the rapid culture of nitrified granular sludge and its response to sulfides were investigated.The results showed that under the condition of high inoculation sludge concentration(19.3g/L),sludge granulation was basically achieved within 30 days by gradually shortening HRT(7h to 2h)and increasing influent ammonia nitrogen load(0.5kg/(m^(3)·d)to 3.1kg/(m^(3)·d)).The SVI3=SVI30 was(16.8±0.3)mL/g,and the average particle size of granular sludge was 266μm.The high concentration nitrification granular sludge[(11.9±0.2)g/L]ensured the high load operation of the system(ammonia nitrogen removal load(2.4±0.3)kg/(m^(3)·d)).Sulfides in the influent significantly inhibited ammonia-oxidizing bacteria(AOB)and nitrite-oxidizing bacteria(NOB)in granular sludge,but the recovery of AOB activity was faster than that of NOB,so nitrifying micro-granular sludge achieved the function of nitrification.When the sulfide concentration increased to 10mg/L,the nitrification rate reached about 80%.However,when the sulfide concentration was further increased to 20mg/L,the nitrification rate did not increase significantly.The batch experiments on the 82nd day showed that AOB activity decreased with the increase of initial sulfide concentration,while NOB activity increased,which was closely related to the stratified distribution of AOB(outer layer)and NOB(inner layer)in granular sludge.In addition,the effect of sulfides on nitrifying granular sludge with small particle size(<0.3mm)was more significant.