垃圾渗滤液烟气脱硫--pH值、Fe2+和Mn2+的影响机理研究

研究了利用垃圾渗滤液进行烟气脱硫并同时吹脱去除垃圾渗滤液中氨氮这一互补工艺过程,研究证实,因其较高的碱度、对酸的缓冲能力以及金属离子的催化作用,垃圾渗滤液是一种良好的二氧化硫吸收剂,其对SO2的吸收率可达90%以上,同时渗滤液中的氨氮浓度可从133mmol·L-1降低到78 mmol·L-1.在确定的实验条件下研究了垃圾渗滤液pH值以及Fe2+、Mn2+的催化作用对吸收二氧化硫的影响.实验结果表明,垃圾渗滤液pH值是吸收SO2、吹脱去除氨氮、促进Fe2+、Mn2+的催化作用以及提高吸收尾液可生化性的关键因素,需要将垃圾渗滤液吸收终点的pH值控制在6.0左右;在较低pH值条件下,Fe2+、Mn2+的催化作用对于保持较高的二氧化硫去除率具有重要作用;虽然Fe2+、Mn2+的催化机理类似,但Mn2+的催化作用优于Fe2+.研究结果证实了烟气脱硫和垃圾渗滤液氨氮吹脱处理相结合的工艺的可行性和优越性.

Study on Flue Gas Desulfurization with Landfill Leachate--Effects of the pH Value and Catalysis of Fe2+ and Mn2+

Chemical absorption of SO_2 in flue gas was combined with the reduction of ammonia-nitrogen in landfill leachate. It was demonstrated that being of high alkalinity,buffer ability and catalysis of some metal ions,the landfill leachate was an effective absobent for SO_2.The desulfurization ratio was over 90% while the concentration of ammonia-nitrogen in landfill leachate was reduced from 133 mmol/L to 78 mmol/L. Several factors, such as pH value, catalytic effects of Fe~(2+) and Mn~(2+), were investigated to observe their essential influences on this dual effective process. The experiment results indicate that the pH value of landfill leachate was the key factor to SO_2 absorption, ammonia stripping, the catalytic effects of Fe~(2+) and Mn~(2+) and the biodegrability of flee leachate. Terminal pH value of landfill leachate should be kept at about 6.0. The catalytic effects of Fe~(2+) and Mn~(2+) was important to SO_2 absorption at low pH. Catalytic activity of Mn~(2+) was higher than that of Fe~(2+) although their react steps were very similar.