Isolation, Identification And Characterization Of Aniline Aerofloat-biodegradation Bacteria

Aniline aerofloat (dianilino dithiophosphoric acid), with its molecular formula(C6H5NH)2PSSH, is an organic flotation reagent used frequently in lead sulfide mineral (PbS) flotation. It’s a refractory organics in floatation wastewater for it’s hard to be degraded and remain for long. Chemical and physical method is widely used for treating aniline aerofloat, but it will bring high cost and secondary pollution.Activate sludge which came from Lijiao Sewage Plan was cultivated and acclimated by aniline aerofloat in SBR (sequencing batch reactor) system in laboratory. Strain AAF039which degraded aniline aerofloat was separated and selected from it. The optimal condition for growth of strain AAF039and biodegradation of aniline aerofloat was researched, contained substrate concentration, pH and temperature. Strain AAF039was detected in community DNA fingerprints generated by PCR coupled with denaturing gradient gel electrophoresis. physiological, biochemical. The biodegradation pathway of aniline aerofloat was inferred by relationship between substrate concentration and COD with physicochemical phenomena of medium.The results showed that strain AAF039could used aniline aerofloat as sole carbon source. The colony characteristics of it were round, transparent white and wet. It was gram-positive bacilli and100%related to Bacillus vallismortis with the morphology which was short rhabditiform, flagellated and having gemma. The optimal pH and temperature for cell growth and aniline aerofloat biodegradation were7.0and35℃, respectively. It degraded aniline aerofloat by89.11%in21hours. The relationship between substrate concentration and COD indicated that intermediate products were generated and contributed stable COD during biodegradation. The biodegradation pathway of aniline aerofloat was based on the biodegradation mechanism of aniline with physicochemical phenomena of medium.In a short word, strain AAF039was detected as the most perspective strains in this study. The optimal pH and temperature for cell growth and aniline aerofloat biodegradation were7.0and35℃, respectively. It supported theory for biological treatment of floatation wastewater.