The Dynamic Experiment Study On The Treatment Of Acid Mine Drainage By Combining Adsorption Method With Microbial Membrane Method

The pollution of acid mine drainage (AMD)is a problem all over the world, its characteristics contains low pH, lots of heavy metal ions, high concentration sulfate and so on. At present, most of study on AMD is the treatment of heavy metal ions or sulfate generally. The experiment adopt the combination adsorption method and microbial membrane method to treat AMD, and it can achieve the goal of removing sulfur, removing heavy metal ions and reducing acidity synchronously. Bentonite alkaline composite particle is used as absorbent, sulfate-reduction bacteria (SRB) is used as microbial of hanging membrane and the fermentation liquor of domestic sewage, chicken feces, saw dust was used as new organic carbon sources. The removing effect on AMD, the way of combining adsorption method with microbial membrane method, the synergistic mechanism of purification and volume hydraulic load are studied through dynamic experiment.The aim is to develop a new water treatment technology which can remove sulfur, remove heavy metal ions and reduce acidity synchronously, and that provides a reference for practical applications. The results show that:1) Compare the five biological absorption columns'(two are filled with 8:2,5:5 bentonite-steel slag composite particle and biological carrier layered, two are filled mixed and the last one is only filled with biological carrier) removing effect of AMD, it determined that 5:5 bentonite-steel slag composite particle was better than 8:2, bentonite composite particles and biological carrier layered was better than mixed and the more than only biological carrier. The biological absorption column which is filled with 5:5 bentonite-steel slag composite particles and biological carrier layered was the best combined way.2) It revealed the mechanism of purification that the combination adsorption method and microbial membrane method can develop synergistic reaction. Bentonite composite particle can remove heavy metal ions efficiently, release alkalinity, neutralize acid and provide good conditions for SRB. S2- generated by SO42- reduction reacts with heavy metal ions (Fe2+, Mn2+, Cu2+, Zn2+) to produce subsidence. Sulfur and heavy metal can be immobilized. Bentonite composite particle regenerated can continue to absorb heavy metal ions. The combination of two can benefit mutually and develop synergistic reaction.3) In order to determine the best volume hydraulic load of the technology, the biological absorption columns'(under three different volume hydraulic load) removing effect of AMD. The optimum operation parameters:volume hydraulic load is 0.3235m3/(m3·d), hydraulic retention time is 3d. The effluent pH can reach 6-9, the effluent concentration of heavy metal ions (Fe2+ Mn2+, Cu2+, Zn2+) can reach Omg/L, the effluent concentration of SO42-can reach 121mg/L. With Cu2+as control factor, the through cycle is 64d.4) Owing to the fermentation liquor of domestic sewage, chicken feces, saw dust was used as new organic carbon sources, there were a little of COD, NH3-N, P in biological absorption columns' effluent. It can adopt constructed wetland enhancement to treat.The combination adsorption method and microbial membrane method treating AMD can achieve the goal of removing sulfur, removing heavy metal ions, reducing acidity synchronously and using waste to treat waste, it is worthy of popularization and application.