Biochemical Treatment of Wastewater Containing Partially Hydrolyzed Polyacrylamide

Abstract

Partially hydrolyzed polyacrylamide (HPAM) in production water after polymer flooding in oil filed causes environmental problems, such as increases the difficulty in oil-water separation, degrades naturally to produce toxic acrylamide and endanger local ecosystem. Two hydrolyzed polyacrylamide-degrading bacterial strains, named P-1 and P-2, were isolated from the produced water of polymer flooding. The influence factors on mixed bacteria to degrade hydrolyzed polyacrylamide-containing wastewater were optimized. The optimum process conditions were as follows: polyacrylamide (i.e., hydrolyzed polyacrylamide) which comes from waste water could serve as nitrogen source, K₂HPO₄ serve as phosphorus source, the microorganisms activation times was 2 h, incubation time was 3 d, initial pH was 7, the inoculum size was 5 % (v/v), incubation temperature was 35 ºC, the mineralization degree was 4000 mg L^-1. The main factors affecting degradation rate were nitrogen source, time, pH, activation times, inoculum size and mineralization degree.