| This subject is the branch of "Physiological and Ecology, and Regulation Methods for PAOs (Phosphorus Accumulation Organisms) and GAOs (Glycogen Accumulation Organisms) in Biological Phosphorus Removal System" (50408039) supported by National Natural Science Foundation of China. The adverse environment for the growth and metabolism of GAOs was determined by studying the influences of long-term cultivation and short-term changes under different propionic/acetic acid ratios and pH conditions. The study has a certain guiding significance for enhancing phosphorus removal efficiency of Wastewater treatment plant and maintaining stability and high performance of system operation.Synthetic Wastewater of different propionate/acetate C-mol ratios of 0.1, 0.5, 1, 2 and 10 was applied for long-term cultivation of enriched culture of GAOs, and influences of propionic/acetic acid on sludge cultivation, metabolism, enzyme activity, and stoichiometry were studied. The conclusions are as follows:1) In the long-term cultivation of GAOs at different propionic/acetic acids, it was observed that concentrations of organic acids in anaerobic phase in each reactor were all changed exponentially with time. Meanwhile, with the same concentrations of organic acids per unit microbe, GAOs have faster uptake rate on acetate. With the decrease of propionic/acetic acid, the synthesis and degradation of PHA and the content of PHB in PHA increased, and the anaerobic degradation and aerobic synthesis of glycogen also increased. Microbial growth decreased with the increase of propionic/acetic acid. In addition, different propionic/acetic acid ratios have no significant effects on settling performance of microbe.2) In the case of short-term changes of organic acid ratios, GAOs cultivated with high propionic/acetic acid can immediately uptaked large amount of acetate and used it for metabolism, but for GAOs cultivated with high acetate/propionate ratio, its uptake...
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