高氨氮对具有回流的PN-ANAMMOX串联工艺的脱氮影响

采用具有气升回流的部分亚硝化-厌氧氨氧化串联工艺研究了进水氨氮浓度对其氮素转化特性和微生物群落的影响.结果表明,在恒定氮容积负荷2.8 kg·(m3·d)-1的条件下,当进水氨氮浓度上升到700 mg·L-1时,好氧区和厌氧区的p H值波动很小,FA浓度分别维持在5 mg·L-1、10 mg·L-1左右,未对功能微生物产生抑制.好氧区的亚硝酸盐生成速率稳定在1.5kg·(m3·d)-1,厌氧区的氮去除速率稳定在31.49 kg·(m3·d)-1,联合工艺的总氮去除速率稳定在1.67 kg·(m3·d)-1.当进水氨氮浓度上升到900 mg·L-1时,各区域FA和FNA浓度才出现上升,联合工艺的总氮去除速率稳定在1.52 kg·(m3·d)-1.厌氧区出现亚硝酸盐的积累,厌氧氨氧化细菌的活性未出现明显的抑制现象.说明在联合工艺运行过程中,回流可有效地缓解各区域p H值的大幅波动,同时稀释了高氨氮浓度所形成的FA对功能微生物的毒性作用.

Effect of High Ammonium on Nitrogen Removal in an Partial Nitritation-ANAMMOX Process with Reflux System

The effect of influent ammonia on nitrogen transformation characteristics and microbial communities in partial nitrification-anaerobic ammonia oxidation (PN-ANAMMOX) process was studied by using a series of partial nitrification and ANAMMOX process with air-lift reflux device.The results showed that when the influent ammonia concentration was increased to 700 mg·L^-1 and the nitrogen volume load was stabled at 2.8 kg·(m³·d)^-1, the fluctuation of pH value was very small in aerobic and anaerobic zone.In the aerobic and anaerobic zone, FA concentrations were maintained at 5 mg·L^-1, 10 mg·L^-1, respectively, which did not inhibit the growth of microorganisms.Nitrite produce rate was stabled at 1.5 kg·(m³·d)^-1 in the aerobic zone, and nitrogen removal rate was stabled at 31.49 kg·(m³·d)^-1 in anaerobic zone, the total nitrogen removal rate was stabled at 1.67 kg·(m³·d)^-1 in combined process.When the influent ammonia concentration was increased to 900 mg·L^-1, the FA and FNA concentration were increased in each areas, total nitrogen removal rate was decreased and stabled at 1.52 kg·(m³·d)^-1.The nitrite was accumulated in the anaerobic zone, and there was no significant inhibition of ANAMMOX bacteria.Our findings indicated that the reflux can effectively alleviate the fluctuation of pH in each area, and dilute FA concentration which is toxic to microorganisms.