[pH regulation to continuous treatment system of high-sulfur antibiotic wastewater]

With the pH regulation to the batch-treatment system as a control, the effect of different pH levels, i.e., 7.0, 5.1, 4.1, on the treatment efficiencies and the contents of yeast and bacteria content in aerated column were investigated for the continuous micro-aerobic treatment system of the antibiotic wastewater. With the decrease in pH levels in aerated column, the COD removals reached 53%, 42% and 45%, respectively, BOD5 removals were 79%, 58% and 50%, respectively, and the DHA activities (TF/MLSS x t) of the sludge were 47,088, 10,506 and 14,390 mg/(g h), respectively, during the three experimental stages. The results on the basis of scanning electron microscope (SEM) and fluorescent in-situ hybridization (FISH)-flow cytometry (FCM) showed that different pH levels didn't affect the contents of yeast and bacteria in the aerated column content at three different pH levels, and bacteria were the dominant microbes with a content of above 98% throughout the experimental periods. In addition, the variation of pH levels had the same influence on the treatment efficiencies of both continuous treatment system and batch treatment system, although different changes of microbial ecologies happened in these two systems.