Study on Production of Polyhydroxyalkanoates (PHAs) by Bacterial Consortium from Excess Sludge

Abstract

In this experiment, the synthesis of PHAs is studied by the microbial flora in the activated sludge, the aim is to reduce the production cost of PHAs and realize the reduction and resource recovery of residual sludge. The remaining sludge from this experiment was taken from the second sink of Lizhigou sewage purification plant, the PHAs was synthesized by using glucose and sodium acetate as carbon source culture and acclimatization sludge. Under normal temperature, the control PH was between 6.9 and 8.4, and COD was in the first stage: N: P=100:5:1, continuous cultivation of 7-15d, and the second stage controlled COD: N: P=200:10:2. By regulating COD, the accumulation of PHAs reached 7.24% when COD=1000. By controlling the time of N source and P source respectively, it is found that the synthesis quantity of PHAs increased with the control time, up to 4.03% and 5.01%. The experiment is also found that the higher the C/P ratio, the greater the synthesis amount of PHAs, which can reach to 6.53%, but the sludge is easy to expand at this time.