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This paper studies a fermentation and yeast fused strain and its treatment of heavy metal wastewater containing chromium. Yeast fused strain on the adsorption properties simulated wastewater containing chromium experimental results show that, under optimum conditions, 10g bacteria (wet weight, moisture content (78 ± 2)%) treatment 1L concentration of 10mg / L of chromium-containing wastewater to rate of 90% in addition to the residual concentration of Cr (VI) and Cr (Ⅲ) were lower than the \Adsorption conditions: pH ≤ 3, saturated adsorption time 2h, a temperature of 30 ° C to -35 ° C, cast fungus amount of 10g. The adsorption kinetics models could meet the Lagergren pseudo-first quasi-two grain interior diffusion model fitting parameter R2 more than 0.92, indicating that the bacteria on the adsorption of Cr (Ⅵ) is a surface adsorption, internal adsorption combining the complex process of the internal diffusion. Under optimal conditions, the yeast fused strain obvious effect on the adsorption of Cr (Ⅵ), but hardly adsorb Cr (Ⅲ). Some of the hexavalent chromium is reduced to trivalent, free in solution in the adsorption process. Found by Fourier transform infrared spectroscopy before and after adsorption bacterial surface groups, alcoholic hydroxyl group, an amide, a phosphoric acid diester group, amino group, etc., a variety of groups involved in the reaction. The SEM observation bacterial surface before and after adsorption draw, Cr (Ⅵ) toxic effects on cell, poisoned by a greater extent than Cr (III). Fused strain of yeast culture conditions optimization experiments showed that cultured yeast fused strain optimum conditions: inoculum for the training of 10% of the volume of liquid, the optimal incubation temperature of 20 ℃ ~ 25 ℃, sufficient oxygen in the culture medium, the early starting pH 8, carbon and nitrogen ratio of 4, the dosage of inorganic salts MgSO4 0.02 ~~ 0.5g / L, incubation time 60h ~ 72h. The the yeast fusion fermentation experiments, yeast fused strain in a fermentor and shake flask culture both training methods, similar to the trend of cell growth, yeast fused strain fermenter certain lag in the growth process, and fermentor produced slightly lower amount of bacteria. Aeration and the shake-flask method showing two adsorbed reaction trend. Shake-flask method processing wastewater volume, is easier to achieve than the aeration adsorption saturation; reached adsorption saturation shake-flask method at 2h, aeration until the reaction 3h removal there is still room for improvement, but the two go In addition to the rate difference is not obvious. The yeast fused strain of actual wastewater adsorption experimental results show that: only handle wastewater containing chromium, Hardware, plating two real wastewater, the removal efficiency of total chromium at pH = 1 to 3, the highest bacteria culture time for 42h, 64h, the removal rate of 77%, 68%; consider the integrated treatment of bacterial actual wastewater, the bacteria has good adsorption effect of chromium removal rate of 92%, but the COD, total nitrogen , total phosphorus removal is not ideal, the highest removal rate of 16%, 22% and 5%, respectively. The desorption experiment results show that, H2SO4, NaOH, EDTA, AIC13 desorbent of adsorption saturation yeast fused strain certain desorption effect. 2.5 mol / L NaOH desorption effect best, the desorption rate reaches 87.99%. The greater the concentration of desorbent, the desorption best.
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