title: Kinetics and thermodynamics of biodegradation of hydrolyzed polyacrylamide under anaerobic and aerobic conditions.
abstract: Kinetics and thermodynamics of hydrolyzed polyacrylamide (HPAM) biodegradation in anaerobic and aerobic activated sludge biochemical treatment systems were explored to determine the maximum rate and feasibility of HPAM biodegradation. The optimal nutrient proportions for HPAM biodegradation were determined to be 0.08g·L(-1) C6H12O6, 1.00g·L(-1) NH4Cl, 0.36g·L(-1) NaH2PO4 and 3.00g·L(-1) K2HPO4 using response surface methodology (RSM). Based on the kinetics, the maximum HPAM biodegradation rates were 16.43385mg·L(-1)·d(-1) and 2.463mg·L(-1)·d(-1) in aerobic and anaerobic conditions, respectively. The activation energy (Ea) of the aerobic biodegradation was 48.9897kJ·mol(-1). Entropy changes (ΔS) of biochemical treatment system decreased from 216.21J·K(-1) to 2.39J·K(-1). Thermodynamic windows of opportunity for HPAM biodegradation were drawn. And it demonstrated HPAM was biodegraded into acetic acid and CO2 under laboratory conditions. Growth-process equations for functional bacteria anaerobically grown on polyacrylic acid were constructed and it confirmed electron equivalence between substrate and product.
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China; College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Lanmei
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China; College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China. Electronic address: mtbao@ouc.edu.cn.
authors.forename: Mutai
authors.initials: M
authors.lastname: Bao
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China; College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Miao
authors.initials: M
authors.lastname: Yan
authors.affiliation: College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Jinren
authors.initials: J
authors.lastname: Lu
mesh_terms: D000085:Acetates / Q000378:metabolism; D000180:Acrylic Resins / Q000378:metabolism*; D000332:Aerobiosis; D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D004583:Electrons; D019277:Entropy; D006859:Hydrogen / Q000378:metabolism; D006868:Hydrolysis; D007700:Kinetics; D012722:Sewage / Q000382:microbiology; D013816:Thermodynamics; D014783:Viscosity; D062065:Wastewater / Q000737:chemistry; D000099166:Polyacrylamides
chemical_list: D000085:Acetates; D000180:Acrylic Resins; D006859:Hydrogen; D012722:Sewage; D062065:Wastewater; D000099166:Polyacrylamides
keywords: Biodegradation; Hydrolyzed polyacrylamide; Kinetics; Thermodynamics