Studies On The Adsorption Of Heavy Metal By Microbial Flocculation

In recent years, due to the rapid development of industry, the humans mining, smelting, processing and commercial manufacturing activities toward heavy metal increased, causing a lot of heavy metals such as lead, mercury, cadmium, cobalt etc into the environment of atmosphere, water, soil, leading to serious environmental pollution. Heavy metals in the environment have long-term, non-mobility and other characteristics which have bad effects on biological and human. The conventional methods to treat heavy metal wastewater, such as chemical precipitation, adsorption, chemical oxidation-reduction, ion exchange, membrane separation, and solvent extraction, etc. But these methods have high-energy requirements and incomplete metal removal. In recent years, microbial adsorption method was used to remove the heavy metal from solution, with its rich source of raw materials, low cost and few secondary pollution.Microbial flocculant is to use biotechnology, is taken from microorganisms or their secretions extract, purification, then get a safe, efficient, and natural degradation of water dispose reagent.This experiment filtrated the microbial flocculants activity generated bacteria F1-2, Z-2-1, Z-2-2from the earth nearby the Gantang lake of the Jiujiang, with single-factor analysis methods on its best cultivation condition is optimized, and the results show that:F-1-2, Z-2-1, Z-2-2in150r/min thermostatic oscillator cultivation, best of carbon sources are sugar, optimum dosage respectively to15%,16%,15%. The best nitrogen source are peptone, NaNO3, NaNO3, the optimum amount of0.1%,0.28%,0.35%. Best inorganic salt is KC1. Optimum PH respectively for6, natural,8; Strain F-1-2, Z-2-1, Z-2-2of the best cultivation time is72h. The best temperature is30℃, the rate of adsorption of Cu2+were68.6%,73.3%,82.8%, the rate of adsorption of Cd2+were61.4%,62.7%,70.1%, the rate of adsorption of Zn2+were72.1%,71.9%,87.1%.