Isolation Of Salt-tolerant Microorganisms And Its Application In Hypersaline Wastewater Treatment

With the process of industrialization and urbanization,our country’s waterrequirement and almost the same amount of sewage emissions are rising year byyear.increasingly serious water pollution,the deteriorating water quality,makeavailable water resources are scarce.looking for more economic and efficientwastewater treatment technology become a pressing social sustainable and healthydevelopment of the problem.High-salinity wastewater with high salt concentration on the toxicity of microbes,the traditional biological treatment effect is significantly reduced,Increased thedifficulty of high salt waste water treatment.Unique biological characteristics ofhalotolerant microorganism,opening up a new way for the efficient processing ofhigh-salinity wastewater.SBR (sequencing batch type activated sludge process) is widely used inhigh-salinity wastewate biological treatment.because the equipment is simple andflexible, and the higher activated sludge,and the impacted resistant ability, and highprocessing efficiency etc.This paper isolats halophilic (halotolerant) strains from soil samples,identifing togenera,measuring the growth salinity range,and preliminary researches strains on theability of degradation of high-salinity wastewater.The method of SBR is adopted totreat high-salinity simulating wastewater,with steadily improving salinity,domesticating salt-tolerant activated sludge, collecting and monitoring systemoperation parameters, comprehensive monitoring and analysis effluent quality onvarious stages of the cultivation and domestication processes by PCR-DGGEtechnique, studying the relationship between the dynamic change in communitystructure and the active sludge degradation of high-salinity wastewater for differentstages, drawing the following main conclusions:Soil samples contained abundant halophilic (halotolerant) microorganisms,totallyseparating24strains of morphological significant differences and growth with widerrange of salinity.Preliminary determined its classification statuswith morphologicaland physiological characteristics.Different salt-tolerant microbial community showedbetter degradation ability than conventional activated sludge on high-salinity simulating wastewater.Salt-tolerant activated sludge was domesticated by the method of graduallyincreasing salinity,during the process of domestication,SBR reactor system showedstable function,the high of efficiency on removal ratio of COD and ammonianitrogen.Advantage flora which had strong adaptive ability to the High saltenvironment leaded a dominant position,microbial interactions in the sludge systemShowed the function of degradation of high-saltinity wastewater at the macrolevel,which marked the completed halotolerant activated sludge domestication.Studied sludge samples of the active sludge on different domestication stages byPCR-DGGE,the difference between domestication stage of different salinity and indifferent periods of the same stage,performance with the stripe number, location andbrightnesson on the DGGE fingerprint.With the domestication time increasing and thesalt concentration improving,population diversity experienced the evolution processof a decreasing first and then gradually increasing.Sludge community structure atsalinity of0.8%and1%had highest homology in the domesticationmaturity.Fingerprint accurately reflected the results that how community structurechanged over different stages of the sludge domestication.