Nowadays

the researches of VFAs production by excess sludge focused mainly on the utilization of the excess sludge from wastewater treatment plant (WWTP) in east and north areas of China

and few on the sludge in south China. Meanwhile

the related on-site experimental research for VFAs production property by sludge from WWTP in south China was rarely reported. Research on VFAs production by excess sludge was conducted at alkaline condition by semi-continuous anaerobic reactor

which was located at Dinghu wastewater treatment plant in Zhaoqing

Guangdong Province. The results showed that great hydrolysis and acidification properties of the system could be achieved at alkaline condition (pH 10.0). The percentage of VFAs-COD/SCOD was 73.89% in average

which was about 2%—15% higher than that of existing similar researches. Meanwhile

only small amount of polysaccharide and protein were accumulated (5%—15% of SCOD). Acetic acid was the main component of VFAs with the proportion of 51.43%. And the dominant microbial species in the system were all nearly acid production microorganisms including Acetoanaerobium sp.

Clostridiales bacterium Z-810

Proteinivorax tanatarense strain Z-910 and Tissierella sp.

among which Acetoanaerobium sp. and Clostridiales bacterium Z-810 were not reported in other similar researches. The excess sludge reduction rate of 33.5% could be achieved.