低浓度SO_2诱导驯化选育脱硫菌研究

Domestication Study About Desulfuration Microorganism from Oxidation Ditch by Low Concentration SO_2

采集于城市污水处理厂氧化沟的微生物用100～2000mg/m3低浓度SO2气体通入0.5h停1h的方式诱导驯化6d以上,得到生长繁殖速度快、活性高、具有能将亚硫酸根氧化为硫酸根并从中获取能源的脱硫菌,该混合菌中优势菌属氧化亚铁硫杆菌,呈革兰氏染色阴性,杆菌单极生鞭毛运动的专性无机化能自养性菌.驯化过程中逐渐提高SO2浓度、供氧速率以及适时添加N、P、K等营养液对优势菌种的驯化生长起关键作用,驯化所得脱硫菌可只以低浓度SO2气体为能源进行生长,对亚硫酸根水溶液降解速率达160g/(m3·h),生化降解率超过50%.在填拉西环塔式反应器中降解不高于5500mg/m3的SO2气体,气体接触时间3s时SO2的净化效率达98%以上,出口SO2气体浓度低于100mg/m3,生化降解率接近80%,对15000mg/m3SO2气体的净化效率也高于95%.

An excellent desulfuration microorganism with a quick growth and propagation,high activation,high efficiency of removing SO2 is obtained from oxidation ditch of a city sewage treatment plant by inductive acclimatization over 6 d with low concentration SO2 gas（100-2 000 mg /m3）.The desulfurition microorganism get their energy sources for growth from transforming SO2（SO23-） to SO42-.The predominant bacterium of the desulfuration microorganism has the same characteristic with Thiobacillus ferrooxidans（T.ferrooxidans）,which showed that it was Gram negative,short rod bacteria with a single polar flagellum under a microscopic examination,and obtained its nourishment through the oxidation of inorganic compounds.The technology process condition of domestication and desulfuration of microorganism are particular studied,and the results showed that aerating time,SO2 flux and time to provide nutriment contained N,P,K to microorganism were very important.They have an ability with degradation rate of 160g /（m3·h） and degradation efficiency over 50% to transform sulfite to sulfate in liquid phase.The bacteria have a 98% of removing efficiency and over 80% of biodegradation efficiency for the 5 500 mg /m3 SO2 gas and the outlet concentration of SO2 is lower than 100 mg /m3,and also have a 95% of removing efficiency for 15 000 mg /m3 SO2 gas in the packed tower reactor with Raschig ring at 3s contact time.