Decolorization of textile wastewater using thermophilicbacteria isolated from the wastewater and returned to the productionline

Background and Aim : Materials and Methods: From a wastewater treatment plant (wastewater)۱ * in Kashan, samples were taken and bacteria that decompose the existing dyes of the wastewaterwere isolated. TSB, effluent, modified M۹, TSA and agar effluent were used to enrich and screenthe bacteria that degrade wastewater dyes.Methods : Using M۹ medium containing dye at ۲۶ to ۵۳ ° C, different strains (temperate,thermophilic, salt-loving) of the dye decomposer were selected from among the primary isolatedbacteria. Identification of the selected bacterial strain was performed by sequencing the ۱۶S rRNAgene.Results : ۴۷ bacterial strains were isolated using culture media containing degradable dyes inwastewater. The decolorization ability of these strains was observed from ۲۲ to ۷۸.۵% during threedays of incubation at a temperature of (۲۶۳-۳۷-۳۷-۴۲-۴۸-۵۳ ° C). Among these strains, ۳ strainsin the consortium had the ability to grow well in the environment containing dye and remove dyeby ۹۵.۵%. The optimum conditions for dye removal by response procedure (RSM) are ۴۲ ° C, ۱%salt concentration, ۵۰ mg / l dye concentration and pH ۷.Conclusion : The amount of decolorization of SN۷, SN۱۰ and SN۵ strains in aerated (on shaker)and static (anoxic) conditions indicates more paint removal in static state. Better decolorizationwas observed using two-stage aeration method and then static conditions. Industrial use of thisstrain in textile wastewater treatment has been suggested.

کلیدواژه ها:

various bacteria (moderate ، thermophilic ، halophilic) ، color analysis ، azo and reactivedyes