[Investigation of PHA polymer production from sludge of municipal wastewater treatment plant and its effect on sludge volume reduction]

Owing to the fact that the major environmental problem is production of surplus sludge in wastewater treatment plant, reducing the volume of produced sludge was objective of this research. An anaerobic-aerobic SBR with working volume of 10 L was used to make micro-organism adapted and a polymer production reactor [PPR] with working volume of 1.5 L was used for producing polymer munisipal wastewater which contained different concentration of volatile fatty acids was consodered as the feed source [acetate and propionate] and this system was evaluated with SRT of 5, 7 and 10 days. The maximum polymer production efficiency observed within 5 days [SRT=5 days] though this efficiency was not significant in comparison with the two others time courses study. In this research the maximum polymer production efficiency at optimum condition was 25% of the sludge dry weight. Experiment revealed that producing polymer from activated sludge reduced the volume of sludge and the maximum reduced sludge volume was obtained 19%