Study On The Microbial Flocculant And Cell Fusion Technology In Dyeing Wastewater Treatment

Dyeing wastewater is one kind of high-concentration organic waste water withbad biodegradability and high chromaticity.These characteristics make it hard to treatand cost highly.This thesis based on highly efficient multiple microorganisms andused the degradability of the fusant built by PEG Cell Fusion technology to treatdyeing wastewater for the first time.Eight strains with high flocculating capacity were screened from the outfall ofdyeing company.Two arbitrary strains were mixed and cultivated to build multiplemicroorganisms.28 kinds of bacteria were obtained,and the best was namedDXFH-1.The optimal cultivating condition for MBF production was listed asfollowing:1.5ml MBF,pH 7.0,30℃,and 160 rpm.Under this situation,theflocculating activity could reach 90.2%.Dyeing wastewater was treated by MBF produced by DXFH-1.The orthogonalexperiments showed that the optimal condition of COD_Cr and chromaticity removalefficiency was that:2.0ml MBF/50ml fermentation medium,5.5ml 1%CaCl₂,pH 10.0 and settled for 30 minutes.Under this situation,the COD_Cr concentration droppedfrom 730.50mg/L to 242.67mg/L,the removal efficiency could reach 66.8%;Andthe chromaticity dropped from 220.0 to 37.6,the removal efficiency could reach82.9%.The kinetic equations of COD_Crand chromaticity removal efficiency were:After treated by DXFH-1,Wastewater's quality did not reach the dischargestandard.This study sought to take bioaugmentation to improve the performance ofDXFH-1 in order to improve the treating efficiency of dyeing wastewater.ThroughPEG protoplast fusion technology,we got a stable fusant named DXRH-1.Dyeing wastewater which had been treated by DXFH-1 was treated by DXRH-1.The orthogonal experiments showed that the optimal condition of COD_Cr removal efficiency was that:DXRH-1 5.5 ml,pH 6.5,30℃and 160rpm.Under thissituation,after 72 hours ,the COD_Cr concentration was dropped from 242.67 mg/L to92.24 mg/L,the COD_Cr removal efficiency could reach 62.0%.The kinetic equationof COD_Cr degradation was that:Research showed that:UsingMBF produced by DXRH-1 treated dyeingwastewater for 30min,and then using the DXRH-1 degraded the dyeing wastewaterfor 72h.Through this two-step,dyeing wastewater's COD_Cr from 730.50 mg/L to92.24 mg/L and the chromaticity declined from 220.0 to 37.6.These two parametershad reached the first request of dyeing wastewater discharge standard(GB 4287-92).Cheng Binbin(Environmental science)Directed by Prof.Lin Bo...