Study On The Process Conditions And Mechanism Of Heavy Metals Adsorpted By Sphaerotilus Natans

With the development of industry, the pollution of heavy metals has been a prominent problem in the field of enrionmental protection.Besides, Sphaerotilus natans is a kind of main filanmentous bacterium with typical sheathed-forming in activated sludge.It has strong degradative ability to organic and toxic contaminant in water and makes a important effect on process of waste water treating.So the paper highly reports the general situation of studies on Sphaerotilus natans adsorpting heavy metals, and the results will provide some theory proof for biosorption by Sphaerotilus natans in the process of pollutes-water treatment in the future,The studies that we have done as follows:1.By enrichment culture and streaking, combined with primary and compound screening methods, One strain of Sphaerotilus natans FQ32 which could initially enduring heavy metals was successfully isolated from activated sludge.2.Cell morphology and structure,cultural characteristics,physiology and biochemistry of FQ32 were studied.And based on Bergy's Manual of Determinative Bacteriology 9th (1994), the strain FQ32 was identified as Sphaerotilus natans in the Sphaerotilus genus.3.By domesticating, the concentrations of Pb²⁺, Hg²⁺, Ag⁺, Zn²⁺ which Sphaerotilus natans FQ32 could endure arrived at 120mg/L, 8mg/L, 12mg/L, 20mg/L,and preparing with the wildness bacteria, the capacity of endure have differently improved 50%, 233 %, 50% , 25%.4.The studies on the conditions of adsorpting Pb²⁺, Hg²⁺, Ag⁺by Sphaerotilus natans FQ32 indicate that the optimum conditions of adsorpting Pb²⁺are at initial concentration of Pb²⁺50mg/L, pH6.5-7.0, biomass0.6mg/L, bacteriumage32h, biosorption of time 60min, emperature 30℃; the optimum conditions of adsorpting Hg²⁺ are at initial concentration of Hg²⁺12mg/L, pH7.0, bacteriumage16h, biomass1.0g/L, biosorption time90min, temperature30℃ ; and the optimum conditions of adsorpting Ag⁺are at initial concentration of Ag⁺14mg/L, pH8.0, bacteriumage32h, biomass0.4g/L, biosorption time60min, temperature30°C. And by validate experiments, we know that the most adsorption rate on Pb²⁺, Hg²⁺, Ag⁺ will arrive at 89.98%, 91.08% and 71.75%.5.Pretreat of biomass improve the capacity of adsorpting Pb²⁺, Hg²⁺ by Sphaerotilus natans FQ32, but adsorption impact on Ag⁺by pretreating biomass is...