| PH3 mainly produced in the industrial processes of yellow phosphorus, calcium carbide production, semiconductor industry production, fumigation and ductile iron processing. Among that, the concentration of CO is 80% in the yellow phosphorus and calcium carbide production, is a good chemical raw materials resources. Because the phosphine in the tail gas makes easily poisoning or inactivation of the catalyst for Synthesis Methanol, and influences the resource utilization of included carbon monoxide tail gas. There plants usual use the "torch" for combustion emissions there tail gas, it is a waste of carbon monoxide resources, and cause seriously air pollution. Traditional purification method of phosphine with active carbon method, the catalytic oxidation method, the temperature swing adsorption method, Oxidation in liquid phase reduction method. However, these treatments due to the purification efficiency fluctuating large, cause secondary pollution, higher operating costs factors, it is difficult to industrialization, large-scale applications. Purification of tail gas by microorganisms is a relatively new technology. It is not require high temperature and high pressure, catalyst, low operating costs, complex equipment, no secondary pollution compared with the traditional chemical and physical methods. this paper explore the research of phosphine purification with microorganisms which still had not reported home and abroad.In this paper, the sewage collected from Kunming municipal wastewater treatment plant as a source of bacteria, homemade microbial acclimation device, PH3 in the CO as domesticated gas. Research the screening and domesticating of microorganisms on phosphine purification in the strong reducing atmosphere of CO. Preliminary study on the transformation process of PH3 with Dephosphorization bacteria. Analysis the relation of the amount of PH3 degradation and phosphate ions、generated amount of total phosphorus. And focus on the effect on microbial degradation activity of phosphine, the effects of temperature, the concentration of phosphine gas, nutrients、the amount of trient solution. Provide a theoretical basis and technical methods for CO reduction of phosphine in the atmosphere biological removal of applications and yellow phosphorus tail gas utilization.The bacteria from anaerobic pond of urban sewage treatment plant are a good bacteria source of dephosphorization. PH3 in the atmosphere of CO induced domesticated for bacteria. Over 11d, it can get the dephosphorization dominant bacteria that Propagation speed、high activity、be able to degrade PH3, the optimum growth acidity range between 4.5-5.5. The strains from the aerobic tank are difficult to get the Dephosphorization bacteria in the PH3 atmosphere.It is important for the cycle growth of Dephosphorization bacteria by gradual increase in the concentration of PH3 in the domestication process. Pass into the higher concentration of PH3 will inhibit the growth metabolic of bacteria and decrease activity, resulting in decreased ability to degrade of PH3. The best ventilation concentration of PH3 is about 35 X 10-6.The main product of degradation PH3 by dephosphorization bacteria in CO is phosphate. Under the concentration of PH3 is 12×10-6 and 7×10-6, the conversion rates of PH3 are 68.59% and 65.32% after 24h, respectively. Too high temperature and low temperature will inhibit the dephosphorization bacteria growth, and reduce the degradation rate of PH3. The optimum growth temperature was 30℃.It is need to add Cu2+、Zn2+、Mn2+、Mg2+、Fe3+ in the process of purification PH3 by the domesticated bacteria, because they can promote the effect of dephosphorization. Among that, Mg2+、Fe3+、Mn2+ have a greatest impact on dephosphorization. The factors affect microbial dephosphorization efficiency order is Fe3+> Mn2+> Mg2+> Zn2+> Cu2+. The optimum concentration of metal ion in the broth is Fe3+10mg/L, Mn2+ 5mg/L, Mg2+ 3mg/L, Zn2+ 1 mg/L,Cu2+ 0.5mg/L.The domesticated dephosphorization bacteria can not directly use the CO as a carbon source. Therefore, we need to provide glucose or other carbon in the process of purification PH3 to promote the bacterial growth. |
PDF Full Text Request