The Study Of Phenols Degradation By Immobilized Microorganisms

As the most typical endocrine disrupting chemicals, phenolic pollutants can be harmfulof almost all organisms and have a widely sources. Akylphenols, bisphenol compounds,phenols drugs and natural steroid hormones are common phenolic pollutants. The degradationmethod of the pollutants include physical, chemical and biological method. Physical methodrequired a combination of biological toxicity tests and the chemical methods needed, higheroperating costs. The biodegradation method has the advantage of low cost, a wide range ofaction, higher removal rate. The polyvinyl alcohol carrier was used to immobilize the A111engineering bacteria that is the degrading bacteria to degraded the typical phenolic pollutants,bisphenol A and phenol.The polyvinyl alcohol(PVA) cross-linked by glutaraldehyde was prepared tomicrospheres carriers. The carriers was characterized by FT-IR, XPS, and SEM. The rate ofPVA immobilized A111engineering bacteria was determined by the method of Coomassiebrilliant blue and the rate was10.7%. The option of BPA degradation discussed was that pHwas7, temperature28°C and the initial BPA concentration was50mg/L as the BPAdegradation rate is0.14mg/(L h). The coefficient(r2) was0.959as the kinetics of BPAdegradation by immobilized A111engineering bacteria simulated by the Monod equation.Hydroxybenzoic acid and hydroquinone were the mainly products of BPA degradation withthe GC-MS analysis.PVA microspheres carrier was functionalized by quaternary ammoniumn to FPVAM withpositive charge. The quaternary ammonium showed characteristic absorption peak at996cm-1as FT-IR characterization FPVAM and the N-element was2.47%as the XPS analysis theFPVAM ingredients. The immobilization rate of FPVAM was23.7%, as SEM observationproved this point. There were small toxic effects of the both microspheres carriers withdetermination of microbial respiration rate.The A111engineered bacteria was domesticated by phenol as the sole carbon source andimmobilized with FPVAM carrier. The conditions of phenol degradation showed that thephenol has a higher removal rate under the conditions of pH5-9and temperature of20°C-50°C. The phenol removal by the immobilized A111was optimized by the responsesurface methodology.The most important factors affected the phenol removal were the initialconcentration of phenol and the added immobilized microorganisms. The optimal simulatedresults were at pH of6.94, temperature of29.5°C, initial phenol concentration of48.75mg/Land the immobilized microorganism in a proportion of0.95%. The optimal analog8h phenol degradation rate was up to96.8045%and the verification experiment proved the reliability ofthe model. The coefficient(r2) was0.9515as the kinetics of phenol degradation byimmobilized A111engineering bacteria simulated by the Monod equation.