以圆币草发酵液为碳源时硫酸盐还原菌处理重金属废水

摘要

[目的]探索以圆币草(Hydrocotyle verticillata)发酵液作为碳源时硫酸盐还原菌处理重金属废水的效果,以便于高效去除废水中的重金属离子.[方法]以厌氧污泥为硫酸盐还原菌接种菌群,添加大型水生植物圆币草发酵液,并以乙醇、乳酸钠、葡萄糖、蔗糖和乙酸钠为对照,测定不同碳源下硫酸盐还原效率,分析其对废水中重金属离子(Pb2+,Cd2+,Cu2+,Ni2+)的去除能力.[结果]硫酸盐还原菌能有效利用圆币草发酵液中有机物,在COD/SO42-为1.2、5.0和7.0时硫酸盐最大还原率分别为24.4％、43.6％和60.0％.以发酵液为碳源时硫酸盐还原效率高于葡萄糖、蔗糖和乙酸钠,但低于乙醇和乳酸钠.在添加圆币草发酵液的批次试验反应器中,对低浓度4种重金属离子混合废水具有良好的处理效果,Cd2+、Cu2+、Pb2+和Ni2+的去除率分别为95.2％、98.7％、93.0％和89.6％.当Cd2+、Cu2+、Pb2+和Ni2+浓度为l0 mg/L时,以圆币草发酵液为碳源的批次反应器对4种重金属离子仍具有良好的处理效果,去除率均超过90％,且硫酸盐还原菌的活性没有受到抑制.[结论]大型水生植物发酵液作为硫酸盐还原菌的碳源,不仅能有效进行重金属废水的生物深度处理,而且可以实现大型水生植物的资源化.%[Objective] We studied the use of Hydrocotyle verticillata fermentation broth as carbon source for sulfate-reducing bacteria and to remove heavy metals from wastewater.[Methods] Anaerobic sludge was used as the seed of sulfate-reducing bacteria,and reactors were fed with Hydrocotyle verticillata fermentation broth and synthetic wastewater containing Pb2+,Cd2+,Cu2+,Ni2+ and sulfate.[Results] Sulfate-reducing bacteria could use the organic matter in the fermentation broth,and the sulfate reduction rates were 24.4％,43.6％ and 60.0％ when the ratios of COD to SO42-were 1.2,5.0 and 7.0,respectively.When the concentrations of Cd2+,Cu2+,Pb2+ and Ni2+ were 10 mg/L,the removal rates of these heavy metals were more than 90％,and the activity of sulfate-reducing bacteria was not inhibited.[Conclusion] Hydrocotyle verticillata fermentation broth can be used as carbon source of sulfate-reducing bacteria to treat wastewater containing heavy metals.