为了研究低溶解氧微膨胀前后污泥硝化活性的变化,采用SBR反应器,平均DO浓度为0.6mg/L-0.9mg/L,测定污泥微膨胀前后污泥氧消耗速率曲线。结果表明:发生污泥微膨胀后,活性污泥对COD的去除能力有较大的提高,而对氨氮去除能力却有一定的下降。污泥微膨胀前后的氧消耗速率曲线显示,微膨胀前活性污泥总活性为67.72mgO2/gVSS·h,其中硝化活性为43.12mgO2/gVSS·h,占其总活性的63.67%;而微膨胀后活性污泥总活性为90.49mgO2/gVSS·h,其中硝化活性为23.98mgO2/gVSS·h,占其总活性的26.51%。低DO成为微生物生长的限制性基质,污泥微膨胀的状态下,活性污泥中丝状菌成为优势菌种,而硝化细菌成为非优势菌种,污泥的总硝化活性降低。
In order to investigate the variation of sludge nitrification activity before and after micro-bulking with low dissolved oxygen(DO), with mean DO value of 0.6mg/L-0.9 mg/L,the sequence batch reactor (SBR) was employed to test the oxygen consumption velocity curves before and after micro-bulking. The results showed that COD removal ability increased, whereas the ammonia nitrogen removal effect was decreased with micro-bulking of sludge. The oxygen consumption velocity curves before and after micro-bulking showed that the total activity of activated sludge was 67.72 mgO2/gVSS · h before micro-bulking, of which nitrification activity was 43.12 mgO2/gVSS · h, that is, 63.67% of the total activity. And the total activity of activated sludge was 90. 49 mgO2/gVSS· h after micro-bulking, of which nitrification activity was 23. 98 mgO2/gVSS · h, that is, 26. 51% of the total activity. The low DO value was the limited substrates for microorganism growth. When activated sludge was in the state of micro-bulking, the filamentous bacteria were the dominant bacteria, whereas the nitrification bacteria were subordinate. Thus the total nitrification activity of activated sludge decreased.