Microbial degradation of polyacrylamide by aerobic granules.
To deal with polyacrylamide (PAM) wastewater, granular sludge formed in glucose-fed sequencing batch reactors (SBR) was employed to cultivate PAM-degrading granules. Three replicated SBRs were operated with increasing PAM concentration in the influent from 67 to 670 mg L(-1), and the hydraulic retention time was increased at the same time from 1 d to 6 d during the six-phase of the 43 d acclimation period. The well-acclimated PAM-degrading granules were different from the seeding granules in colour, mean diameter, biomass density and settle ability, and could use PAM as the sole carbon and nitrogen source. In the batch experiments, PAM degradation rate by granules was determined as 2.23 mg PAM g(-1) MLSS h(-1). According to the analysis of the intermediates of PAM biodegradation, PAM was degraded initially through hydrolysis of the amide group, and no acrylamide monomer was detected. With the help of LC/MS, the main intermediate was identified as polyacrylic acid with a low molecular weight. Therefore, the PAM-degrading granular sludge may be employed for removing PAM in the wastewater produced from tertiary oil recovery that uses polymeric flooding technology.
State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, College of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, P.R. China. lilyliu@ecust.edu.cn
Lili
L
Liu
Zhiping
Z
Wang
Kuangfei
K
Lin
Weimin
W
Cai
D000064:Acclimatization; D000180:Acrylic Resins / Q000378:metabolism*; D000332:Aerobiosis; D004785:Environmental Pollutants / Q000378:metabolism*; D061329:Oil and Gas Fields; D012722:Sewage / Q000382:microbiology*; D018508:Water Purification / Q000379:methods; D000099166:Polyacrylamides
D000180:Acrylic Resins; D004785:Environmental Pollutants; D012722:Sewage; D000099166:Polyacrylamides