pH对微生物絮团氨氮转化效率及细菌活性的影响

Effects of pH on ammonium nitrogen conversion efficiency and bacteria activity of microbial flocs

摘要:

研究不同pH （6.5、7.5和8.5）对利用高体革（鱼刺）（Scortum barcoo）淡水养殖系统中的固体废弃物培养的微生物絮团的氨氮转化效率和絮团细菌活性效果的影响，实验温度为29~32℃。结果表明，3个处理组均无亚硝酸盐、硝酸盐的明显积累，对活性磷的平均去除率分别为1.29、0.92、0.80 mg/（L·d）。pH对絮团氨氮转化有明显影响：实验结束时pH 6.5、pH 7.5、pH 8.5组的总氨氮浓度分别为37.71、12.74、17.55 mg/L，pH 7.5、pH 8.5组氨氮向有机氮转化效率均显著高于pH 6.5组。pH对微生物絮团的总微生物活性、微生物含量、异养细菌及硝化细菌的活性无显著影响。pH 6.5组的微生物絮凝团胞外聚合物（extacellular polymeric substances，EPS）的胞外蛋白质、胞外多糖明显高于其他两组。pH 6.5组的微生物絮团的平均粗蛋白含量为20.61%，高于pH 7.5组（18.83%）和pH 8.5组（19.04%）。结果表明：在6.5～8.5的范围内，pH对微生物絮团氮素转化效率有明显影响，对微生物活性影响不显著；pH为7.5和8.5时更有利于微生物絮团对水体中氨氮的同化。

Abstract:

The paper studied the effects of different pH values on the cultivation of microbial floccules utilizing the waste sludge from the recirculating aquaculture system that reared Scortum barcoo. It was carried out in fresh water at 29-32℃. The results showed that there were no obvious nitrite and nitrate accumulations when the pH values were 6.5, 7.5 and 8.5, and the average removal rates of soluble active phosphorus were 1.29, 0.92, and 0.80 mg/L·d. At the end of the experiment, the average concentrations of ammonium nitrogen in the three groups were 37.71, 12.74 and 17.55 mg/L, respectively. It was found that pH value had no significant effect on the total microbial activity of microbial flocs, microbial content and activity of heterotrophic bacteria and nitrifying bacteria. Crude protein and polysaccharide of extracellular polymeric substances of microbial flocs at pH 6.5 were significantly higher than those of the other two groups; the crude protein content of microbial flocs of group pH 6.5 was 20.61%, which was higher than 18.83% of pH 7.5 group and 19.04% of pH 8.5 group. It could be concluded that:pH significantly affected the ammonium nitrogen conversion efficiency, but had no obvious effects on the activity of bacteria on the flocs. the pH 7.5 and 8.5 were more beneficial to the ammonium nitrogen conversion.