BB菌对赤泥pH的降低机理及改良效果探究

Mechanism and Improvement Effect of Pannonibacter Phragmitetus BB on Reducing pH Value of Red Mud

降低赤泥pH是赤泥进行下一步利用和生态修复的重要前提。探索利用了耐盐碱菌株(Pannonibacter phragmitetus BB,以下简称BB菌)对赤泥进行改良。研究发现,BB菌主要通过产生有机酸的方式降低溶液及赤泥pH,最佳产酸条件为:葡萄糖15 g/L、酵母膏9 g/L、培养液与赤泥比例2∶1。震荡和静置培养时BB菌均产生草酸和柠檬酸,但震荡培养时BB菌还产生了乙酸。相关性分析显示,震荡培养时pH的下降主要是由草酸和乙酸引起的,而静置培养时主要是由草酸引起的。BB菌可有效降低赤泥pH,最佳条件下可将赤泥pH由11.71降至8.3左右。此外,BB菌的添加还可明显增加赤泥有机质的含量,最大增加幅度高达72.52%。

Reducing pH value of red mud is a significant prerequisite for utilization and ecological restoration of red mud.Improvement of red mud by saline-alkali tolerance tolerant bacterial(Pannonibacter phragmitetus BB)was explored.The results show that P.phragmitetus BB reduces pH value of red mud by producing organic acid.The optimum organic acid production conditions include glucose of 15 g/L,yeast extract of 9 g/L,ratio of culture solution to red mud of 2∶1.P.phragmitetus BB produces oxalic acid and citric acid under shaking and static condition,while P.phragmitetus BB also produces acetic acid under shaking condition.Correlation analysis shows that reduction of pH value of solution and red mud is mainly caused by oxalic acid and acetic acid in shaking culture;while reduction of pH value is mainly caused by oxalic acid when P.phragmitetus BB is cultured under static condition.Besides,P.phragmitetus BB reduces pH value of red mud from 11.71 to 8.3.