Study On Treatment Of Mine Wastewater Containing High Sulfate By Packed Bed Anaerobic Bioreactor

The use of anaerobic biological methods to treat high-sulfate wastewater is an important branch of anaerobic biological treatment technology.Sulfate mine wastewater produced by mining has low organic content and high salt content.Therefore,the biological method for processing such wastewater requires additional carbon source and the sludge must be salt-tolerant.Based on such characteristics,this study investigated the start of the packed bed reactor,the operating performance under different operating conditions,the impact of high salt on the operating performance,sludge activity,and different salinity through the upflow packed bed anaerobic reactor.The reaction kinetics equation below.Thus explored the feasibility of anaerobic biological treatment of high sulfate mine water.The main content of the study and related results are as follows:After a total of 63 days of operation,the reactor was successfully started.When phase 1 maintains a low COD/SO₄^2-=1,the carbon source is insufficient,the starting effect is not good,and the removal efficiency is about 45%.After that,the COD/SO₄^2-ratio was increased to 2.After 52 days of operation in stage 2,the reactor was successfully started and the sulfate removal rate reached 89.81%.The SRB electron current ratio reached about 50%,the average particle size of the sludge increased from27.29?m to 105.3?m,and the appearance was also dark gray.The sludge in the SEM image showed smoother and clear boundaries;Proteobacteria and Bacteroidetes were still dominant before and after domestication Mycophyta,and Firmicutes,which are related to the degradation of organic matter,have been greatly improved;some of the leading bacteria in the seed mud that play a role in denitrification and phosphorus removal after domestication have become related to the degradation of sugar,and Desulfovibrio has also greatly improved improve.The effects of hydraulic retention time,COD/SO₄^2-ratio,and sulfate loading on sulfate reduction were investigated.The results showed that the appropriate HRT,COD/SO₄^2-and sulfate load were 16h,0.9 and 3kg/?m3·d?,respectively,and the corresponding removal efficiency was 91.07±1.39%;The effect of salinity on sulfate reduction shows that when the salinity is 2%,the effect on sulfate removal is not significant,and when the salinity is greater than 3%,the sulfate removal rate drops significantly.The increase in salinity also led to a substantial increase in the content of extracellular polymer?EPS?,a decrease in the PN/PS ratio,and the conversion of the main EPS component from soluble microbial metabolites to aromatic proteins.In addition,the high salinity also changed the microorganisms from bacillus to filamentous bacteria to improve their salt tolerance;the increase in salt reduced the diversity of microorganisms in the sludge.Firmicutes became the dominant phylum due to its resistance to extreme environments.The former dominant phylum Proteobacteria was greatly reduced by the impact of salinity.More salt-tolerant bacteria became the dominant genus to replace the dominant genus of carbon-degrading bacteria before salt addition,and the increase in salinity also promoted the abundance of Desulfovibrio from 2.20%to 4.79%,indicating that it has a good Salt tolerance.When the salinity is 0%and 5%,the reaction kinetic models are V=206.12S/?0.058+S?and V=298.18S/?0.050+S?.As the salinity continues to increase,the Vmax value continues to decrease,and KS continues to increase,indicating that the sludge activity and the affinity of SRB with the substrate have decreased.