以圆币草发酵液为碳源时硫酸盐还原菌处理重金属废水

Using Hydrocotyle verticillata fermentation broth as a carbon source for sulfate-reducing bacteria to treat wastewater containing heavy metals

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10 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。

Abstract:

[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.