| The production of coal mine water is mainly caused by the influx of surface water and groundwater into the underground mining space.As an important index of mine water pollution,fecal coliform reflects the degree of water pollution by feces.As a valuable water resource,mine water should be treated and recycled.Due to the imperfect underground management system and the untimely monitoring methods,the fecal coliform index in the mine water was good and bad in the past,which seriously affected the production.Therefore,this study starts from the source of mine water,explores the influence of different factors on the growth of fecal coliform in the underground environment,and puts forward the management method of fecal coliform pollution source control.In addition,based on the biological metagenome sequencing of the underground water environment,the bacterial community structure and annotation functional genes were analyzed,and a method for rapid detection of fecal coliform in mine water by fluorescence quantitative PCR with specific primers as the core was designed.This promotes the application of metagenomic sequencing in water treatment detection technology and provides another idea for rapid and quantitative monitoring methods.Finally,the mine water reuse treatment plant was pre-oxidized with sodium hypochlorite to explore the effect of chloride disinfection on the structure of activated sludge flora and the degradation efficiency of pollutants,and the optimal residual chlorine control concentration was obtained to reduce its effect on biodegradability.The microbial culture was carried out at different temperatures in the laboratory,and it was found that it was positively correlated with the start time of the fecal coliform growth index period.In the range of 17-45°C,the higher the temperature,the earlier the microorganism entered the exponential growth period.When the concentration of COD in the mine water reaches about 4000 mg/L,the number of fecal coliforms in the stable growth period reaches the highest.In addition,the effects of waste oil leakage and abandoned solid waste in the underground environment on the number of fecal coliforms were studied.It was found that the addition of gear oil and hydraulic support oil to the medium promoted the growth of fecal coliform,while emulsified oil had a certain inhibitory effect on the growth and reproduction of fecal coliform.Adding different types of solid waste to the medium,such as rubber barrels,cotton yarn,slime and other substances,although it can be used as a biological reproduction carrier,but compared with other environmental factors,solid waste has no obvious effect on the reproduction of fecal coliform.In summary,due to the small difference in temperature and humidity of each tunnel under the mine,it is judged that it is not the main reason for the excessive reproduction of fecal coliform.In contrast,the leakage of gear oil and hydraulic support oil from downhole equipment will cause rapid reproduction of fecal coliform.Therefore,the final conclusion is that the underground production department needs to pay special attention to the emission control of mechanical oil,and achieve the goal of controlling the source of fecal coliform pollution in mine water by strengthening on-site management.There have been research and market-oriented products on PCR detection of coliform bacteria in medicine,but it is the first time to sequence the metagenome of bacteria in mine water and design specific primers.The microbial community structure analysis of mine water showed that Proteobacteria and Firmicutes accounted for more than 95%and 3%of the total biomass,respectively.The phylogenetic tree of the flora was constructed and the structural gene analysis was carried out.It was found that the fecal coliforms in Proteobacteria contained glycolysis family-related genes,and uid A,yic I and lac Z genes were higher in glycolysis genes.Based on the above three genes,three pairs of primers were designed.According to the gene heat map comparison analysis,it was proved that the three pairs of primers had high specificity for fecal coliform in mine water.The detection range was 10~2-10~7 CFU/m L,and the coefficient of variation of fluorescence amplification Ct value was below 2%.In addition,the data difference between the fluorescence PCR method and the national standard filter membrane method was compared and analyzed.It was found that the P value was much larger than 0.05at the significant level ofα=0.05.The Pearson,Kendall and Spearman coefficients were all greater than 0.8,which proved that there was no significant difference between the results of the two detection methods,and the correlation was high.By proving the specificity,sensitivity and accuracy of primers,this study provides a complete step for the construction of similar specific fluorescence PCR methods in environmental system detection in the future.Since the front end of the biochemical treatment of the mine water reuse treatment plant needs to be pre-oxidized with sodium hypochlorite,the relationship between different residual chlorine concentrations and the degradation efficiency of COD and ammonia nitrogen by activated sludge was studied.It was found that when the residual chlorine concentration was controlled within 10 mg/L,the activated sludge had no significant change in COD degradation efficiency,but had a positive effect on ammonia nitrogen removal rate.Excessive residual chlorine will destroy the flocculation structure of sludge microorganisms and reduce the sludge sedimentation performance.The analysis of microbial community structure showed that the destruction of residual chlorine on biochemical system was mainly reflected in the destruction of Proteobacteria and Nitrospirae,which led to the weakening of the ability of sludge to degrade pollutants.At the same time,the effect of residual chlorine is lagging,and the sludge concentration will decrease with the decomposition of residual chlorine.Therefore,considering the back end of the pre-oxidation tank,the sludge is returned to the biochemical tank to supplement the biological concentration,especially the number of Proteobacteria and Nitrospirae,in order to tolerate the impact of high residual chlorine and maintain the degradation efficiency of activated sludge. |
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