The Selection Of Hydro-Equipment And The Research Of Microorganism Cultivation In The WFGD (Wet Flue Gas Desulphurization)

On the basis of foreign and domestic technologies of flue gas desulphurization, this paper refers to the conception that use bio-chemical method to do flue gas desulphurization by combining catalyst of transition metal with the microorganism technology. The objective is to oxidize S (IV) to S (VI) by using the strong oxidation of Fe³⁺, which will be deoxidized to Fe²⁺ at the same time. Then transform Fe²⁺ to Fe³⁺ through the metabolism of the microbe, and maintain the concentration of Fe³⁺ in order to enable the reaction to continue.By analyzing and comparing different absorption equipments of desulphurization, the designs and models of some components have been determined such as the absorption tower, nozzle, fogbroom, pump, blower and so forth. Moreover, based on the analysis of power characteristic of the torrential ball tower, the structure and model of desulphurization experience equipments, especially torrential ball tower, have been designed and established logically and rationally, which accordingly provides the accordance for applying torrential ball tower to the industry.In this paper, DYB1 which has the function of desulphurization and heterotrophic DYB2 which can deal with the high-concentration SO₄^2- were cultivated, identified and preserved. Through different temperature, pH value, cultivation method, inoculation amount, inoculation time and effect of the concentration of Fe²⁺ on the biology amount of DYB1, the optimum cultivation conditions were determined, which was 10% of the inoculation amount, 2.5 of pH value, and 20g/L of the concentration of Fe²⁺. Furthermore, the vibration cultivation under the temperature of 28℃was the optimum environment for DYB1 when it was in logarithm vegetal period. Moreover, through researching the different temperature, pH value, the concentration of Fe²⁺ and the effect of oxygen proof on the biology amount of DYB2, the optimum growth conditions of DYB2 were under the temperature of 38℃, 7.2 of pH value and 300mg/L of the concentration of Fe²⁺ with non-oxygen environment. At the same time, the ability DYB2 deteriorated 2200mg/L-9000mg/L SO₄^2- in the culture medium was also determined. The ratio of the deteriorated ability was 5.7% to 67.6%. The net deteriorated amount was 512mg/L-2240mg/L, and it would come to the maximum when the concentration of SO₄^2- was 5000mg/L.In order to confirm the desulphurization function of these two microorganisms, the desulphurization condition of simulated flue gas was optimized on the basis of desulphurization equipment which was designed and made by ourselves. The optimum desulphurization conditions were determined by adding the amount of DYB1, the concentration of Fe³⁺, and the relationship of L/G, and doing the experiments of effects of absorption liquid volume on desulphurization ratio. The optimum conditions were that the concentration of the fly ash solution was 300mg/L, the added amount of DYB1 was 10ml/L, the relationship of L/G was 7L/Nm³, and the desulphurization ratio could reach 97.5%. The ratio of deoxidization could achieve 29.7% to 83.3% if deal with the high-concentration SO₄^2- by using DYB2. Then the net deteriorative amount of SO₄^2- with 5% inoculation, 10% inoculation, and 20% inoculation were 625mg/L-1120mg/L, 712mg/L-1484mg/L, and 833mg/L-2140mg/L respectively. Accordingly, the secondary pollution of acidic waste water was reduced effectively and availably.