Efficiency And Microbial Characteristics Of Uranium(?) By Uranium-resistant Granular Sludge

Large amounts of uranium tailings and waste water are produced in the uranium mining process, wastewater containing U??? is metal toxicity and radioactivity, damage to the environment and human health. Bioremediation is an effective treatment for uranium contamination. In this paper, anaerobic granular sludge of high biological activity was taken as the subject to do static single factor experiment. The effects of U??? initial concentration,initial p H, adsorbent dosage, dosage of granular sludge and coexisting ions on adsorption of U??? by granular sludge were investigated. Granular sludge has better treatment for U??? under anaerobic conditions, but the uranium in waste water contains dissolved oxygen, this experiment was in micro-oxygen conditions. Scanning electron microscope?SEM?, energy spectrum analysis?EDS?, molecular biology and other analytical tools were used to explore the granular sludge removal mechanism and community structure. Conclusions are as follows:1.The results indicated that the maximum adsorption occurred at p H of 6 and the removal rate was up to 98.7% for initial U??? concentration of 9.6mg/L and adsorbent dosage of 2g at 25?.2.Coexisting ions showed inhibition and promotion, to some extent,on granular sludge removal of U???,which could be promoted by Fe, Fe²⁺ but inhibited by Fe³⁺ and Cu²⁺ with the concentration over 150mg/L. Microbial activity was enhanced with increasing concentration of SO₄^2-. When SO₄^2- concentration was 8mmol / L, U??? was removed substantially after 9 hours' reaction.3.Environmental scanning electron microscope?ESEM? was applied to observe the microstructure of the granular sludge.SEM results showed that spherical bacteria treat U??? of initial U??? concentration of 9.6mg/L, which aggregated together with many bacteria,smooth surface, fine appearance and diameter of 1-3?m, were the dominant microorganisms in granular sludge.It showed a good resistance to uranium.EDS results showed that the existence of uranium in granular sludge.High-Throughput Sequencing technology analysis of granular sludge microbial structure shows there are many uranium-resistant bacterial species, accounted for nearly 20%. Meanwhile,there existed many species suitable for complex industrial wastewater. Granular sludgeshowed good environment adaptability and uranium removal performance.