不同污泥浓度下缺氧FNA对硝化菌活性的影响

为了考察不同污泥浓度(MLSS)下缺氧游离亚硝酸(FNA)对氨氧化菌(AOB)和亚硝酸盐氧化菌(NOB)活性的抑制影响,采用序批式反应器(SBR),基于4种MLSS(8 398、11 254、15 998和19 637 mg·L~(-1))的全程硝化污泥条件下,通过批次试验深入研究4种MLSS下的全程硝化活性污泥经过缺氧FNA(初始浓度为1. 3 mg·L~(-1))处理48 h后,AOB和NOB活性的变化情况.结果表明,缺氧FNA处理活性污泥48 h后,p H值升高0. 9左右,NO2--N浓度并未明显下降;过曝气下,NH4+-N浓度逐渐降解至0 mg·L~(-1),NH4+-N去除速率逐渐升高至4. 4～6. 8 mg·(L·h)-1,并随着抑制MLSS的升高,其所用时越短;抑制MLSS为8 398、11 254、15 998和19 637 mg·L~(-1)时,分别过曝气0～396、0～396、0～372和0～168 h内,亚硝酸盐累积率(NAR)均大于92%,当分别曝气至468、468、444和264 h时,NO2--N浓度和NAR分别降为0 mg·L~(-1)和0%,NO3--N浓度均升高至最高,其值分别为42. 6、49. 9、42. 9和47. 9 mg·L~(-1).

Effect of Free Nitrous Acid on the Activity of Nitrifying Bacteria in Different Sludge Concentrations Under Anoxic Conditions

This study investigated the inhibitory effect of free nitrous acid (FNA) on the activity of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) under anoxic conditions with different mixed liquid suspended solids (MLSS). Sequencing batch reactors were used to study the changes in the activity of AOB and NOB in nitrifying activated sludge based on four different MLSS (8398, 11254, 15998, and 19637 mg·L^-1), after treatment, under anoxic conditions with FNA (at an initial concentration of 1.3 mg·L^-1) for 48 h. The results showed that the pH increased by approximately 0.9, but the concentration of NO₂^--N did not decrease significantly. With over-aeration, the concentration of NH₄⁺-N gradually degraded to 0 mg·L^-1, and the removal rate of NH₄⁺-N gradually increased to a maximum of 4.4-6.8 mg·(L·h)^-1 which time used was shorter with the increase of the inhibition MLSS. The nitrite accumulation rate was more than 92% when the sludge concentration was 8398, 11254, 15998, and 19637 mg·L^-1 and with over-aeration for 0-396 h, 0-396 h, 0-372 h, and 0-168 h, respectively. When aerated for 468 h, 468 h, 444 h, and 264 h, the NO₂^--N concentration and NAR decreased to 0, and NO₃^--N concentrations increased to their highest with the values of 42.6, 49.9, 42.9, and 47.9 mg·L^-1 respectively.