ABSTRACT
ABSTRACT: To identify and prioritize the addition ratio of rice straw and vermiculite as raw materials during sewage sludge composting, the physico-chemical parameters and the changes of microbial communities analyzed by phospholipid fatty acids (PLFA) were investigated. Four runs containing sewage sludge were used: adding only rice straw (Run A; addition ratio (dry weight) rice straw:vermiculite = 1:1 (Run B); addition ratio (dry weight) rice straw:vermiculite = 3:1 (Run C) and adding only vermiculite (Run D). The results showed that the physico-chemical parameters except C/N ratio among four runs have not obvious difference. The totPLFA was abundance in Run C. While in Run D it reached the peak value on day 6, then decreased and was lower than that in other runs after day 12. Based on the PLFA markers of Gram-positive bacteria (G+), Gram-positive bacteria (G−) and fungi, the dominant speices were respectively G− in Run A, fungi and G+ in Run B, fungi and G+ in Run D before day 18. In the later stage all speices began decreasing, exept for a slight increase of bacteria G+ and G− in Run A appeared. It suggested that the addition ratio in Run C was more proper.
