Domesticated Cultivation Of Sulfate-reducing Bacteria And Its Performanceof Sulfate Removal

In this thesis, sulfate-reducing bacteria (SRB-DYB2) was selected for studying,which could deoxidize S6+ to S or S^2-, on account of thermal power plant desulfurization of fluid which could cause pollution for the environment,the main purpose is to train with the desulfurization performance DYB2 bacteria.The colony was isolated from Hohhot chemical soil with sulfate, Baotou mine water and soil samples, and Wudalianchi water samples, using dilution spread and repeat dish sandwish cultivated method, plate pyrogallic acid method and three roller tube culture methods, DYB2 were screened and enriched, to be a single pure colony. It was identified that the Young DYB2 cells were elongated, irregularly globular, 0.4 0.8μm×1.0 4.0μm, single or in pairs, not a common branch, not the formation of mycelium, single polar flagella. The bacteria colony to oval, size of 2 3mm, moist surface opaque, , thick, irregular edge of the central uplift, villous surface, the cells stain Gram-negative.The DYB2 strain belongs to typical Desulfosarcina.The experiment on sulfate-reducing bacteria's growth conditions was investigated. Respective effects of temperature, pH, shaking speed, S^2-concentration and Fe²⁺ concentration on the growth of SRB, the optimization growth conditions was measured.With the optimum conditions, the growth of SRB in accordance with the fixed time made the growth of curve.Anaerobic bacteria sulfate-reducing bacteria (SRB)'s best growth conditions is that pH was 8.0, at 35℃, rotate speed at 150r/min. When S^2- concentration is less than 20mmolL^-1, the growth is not restricted. Fe²⁺ promotes cell growth. When the Fe²⁺ concentration was 32mmolL^-1, bacterial growth curve achieve a higher of the highest OD values and the shortest growth cycle.Growth curve shows that from 0 to 5 hours the bacteria have entered the slow phase, 5 30 hours for the growing phase, 30 45 hours for a smooth period and after 45 hours for a period of recession.It also carried out different temperature, inoculum size, pH, initial sulfate concentration on sulfate removal performance. It is concluded that when at 35℃, inoculum size at 10%, pH is 7.5, the initial concentration of sulfate is 2.704gL^-1, desulfuration is best.DYB2 was domesticated in solution contain sulfate and desulfurization plant tail liquid. desulfurization plant tail liquid mixed with medium proportion of 1:1,2:1,4:1,10:1,the results show that when desulfurization plant tail liquid. mixed with medium proportion is 10:1,desulfurization ratio reached up to 32.9%. When the sulfate concentration was 3000mg/L,the removel rate was 43.2%; When the sulfate concentration in solution of desulfuration tail liquid was 1000mg/L, the removel rate was 34%,after DYB2 was domesticated in solution contain sulfate and desulfurization tail liquid.The results show the relationship between the ln ([SO₄^2-] 0 - [SO₄^2-] t) and time, and then fitting a function which line slope is theμ.Its value response to the bacteria growth rate in the logarithmic phase and reflects the growth of sulfate-reducing bacteria law.It is obtained thatμvalue is 0.02531 when DYB2 cultivated at the optimum conditions.