Study On Preparation Of Complex Microbial Flocculant And Removal Of Heavy Metals In Water

Water resources are the most valuable and indispensable resources on the earth.They are indispensable factors for the development of human society and the maintenance of various animal and plant life activities.With the rapid growth of population and the development of economy and society,the demand for water resources in human society is increasing day by day.The metal ions existing in the nature,many of them are toxic,and because organisms can not lead to heavy metal metabolism original,easy to accumulate in organisms through the food chain,and produced at all levels of animal enrichment.Therefore,the treatment of heavy metal wastewater has become an urgent need to solve the problem of human society environment and ecological environment.Compared with the traditional chemical flocculant,microbial flocculant strain due to its extensive sources,no two pollution characteristics of wastewater treatment effect is good,good water quality water treatment process,become a hot research topic now.The use of composite strain culture experiment based on lead and chromium were tolerated,the preparation of a composite microbial flocculant high tolerance,high yield,good removal effect,easy storage and transportation,and heavy metals of lead,chromium wastewater treatment effect of test.The removal efficiency of lead containing wastewater was also tested.The composite flocculant with patterns of microbial-microbial compound,a strain was screened out from the laboratory by a chromium contaminated soil isolates,the 16S rDNA was identified as Bacillus strains,other strains for the laboratory has screened a strain numbered KD-1.In order to improve the combination effect of microbial flocculation bacteria,the method of compound culture fermentation was adopted to improve the yield and removal efficiency of microorganisms through the combined action of microorganisms.The combination of fermentation broth to 48h composite centrifugal tube,and centrifuged at 4000rpm centrifuge 30min,discard supernatant after centrifugation,microbial bacteria after freeze drying to prepare the compound microbial flocculant preparation.The composite microbial flocculant cultured by fermentation of freeze-dried products of lead,chromium heavy metal removal experiment of simulated wastewater,the results obtained are as follows:the composite microbial flocculant preparation has good effect on removing of lead in wastewater,wastewater for a concentration and volume of the solution at the initial pH the value is 6,the composite flocculant dosage is 8mg,the flocculation reaction time was 50min,the flocculation temperature is 30 degrees centigrade,removal of lead ions to achieve the best,but for the chromium ion wastewater,the laboratory of compound microbial flocculant preparation showed no good removing effect.The analysis of infrared spectrum,the composite microbial flocculant adsorption bacteria before and after SEM scanning electron microscopy analysis and XPS mapping,process preliminary study of heavy metal ions from wastewater of the composite microbial flocculant on chromium and lead.Figure SEM observation of compound microbial flocculant on the growth reaction and the analysis of cell surface morphology,the results showed that the composite flocculant of surface reaction before a large number of short rod are overlapped and stacked together,and there is a certain amount of surface processing waste water pore;lead,short rod composite flocculant surface has obvious the aggregation of mixed flocculation together,and reduce the pore surface.The main component of compound microbial adsorbent is polysaccharide,which contains a small amount of protein.The surface groups of adsorbent mainly include hydroxyl groups,amide groups and carboxyl groups.XPS photoelectron spectroscopy analysis shows that before adsorption of compound microbial flocculant in Pb(?)and Cr(?)exists,and after the reaction,the sample surface is Pb(?)exists,which shows that the composite microbial flocculant and Pb(?)reaction,and for chromium ion and scanning electron microscopy showed that SEM before and after the reaction of compound microbial flocculant morphology did not change much.