| Our country's water polluted due to the rapid economic development,geological structure and other factors.the micro-polluted water of iron and manganese content in our country increasingly more than ?surface water environment quality standard?of drinking water standards set by the requirements.This not only brings inconvenience to people's production and life,but also seriously endangering people's health.In this study,the background value of iron and manganese in micro-polluted water is taken as the concentration of iron and manganese in test water.The self-designed Carbonized Rice Husk is used as filter material and the biofilter of(Bacillus megaterium),Through the biofilter start and run parameters optimized by the process of the final realization of the efficient removal of iron and manganese.At the same time,Fourier transform infrared spectroscopy(FTIR)and scanning electron microscopy(SEM)were used to analyze the surface properties of the filter media.The distribution characteristics of the flora were investigated by using modern molecular biology techniques such as PCR-DGGE and High-throughput Sequencing.The main achievements of this study are as follows:In the experimental study of the filter,the removal rate of Fe and Mn was 89.70% and 99.53% respectively by the contact oxidation method and the biooxidation method,which indicated that the effect of the bio-oxidation method on the iron and manganese was improved obviously.Filter run on the 61 st,use Scanning Electron Microscopy observed inoculated with microbial presence at the filter depth of 20 cm and 40 cm.With the help of PCR-DGGE technique,the microorganisms enriched on the surface of the filter medium were were identified to contain Bacillus sp.The microorganisms were inoculated with microorganisms on the surface of the filter medium.Combined with biofilter on the removal of iron and manganese ions to determine the biological iron removal and removal of manganese biofilter to start successfully at this stage.In this study,the parameters of influent flow rate,influent iron,manganese ion concentration,backwashing strength,backwashing period and backwashing time of biofilter were optimized.The results showed that the influent flow rate was 3 m/h,the influent iron content was 8-10 mg/L,the influent manganese content was 1-2 mg/L,the backwashing intensity was 4 L/m2·s,the backwashing cycle was 4 d,and the backwashing time was 5 min,the concentration of iron and manganese ions in the effluent was 0.002 mg/L,0.011 mg/L and 0.137 NTU,the removal rate was 99%,95%,98.5% respectively.The water above the indicators have reached China's drinking water health standards.Based on the optimization of biological filter operating parameters,the surface morphology and bacterial community structure of filter media with different depths(20 cm,40 cm,100 cm)were studied.The test results show that as the biofilter running state tends to be stable,the surface of the biofilter layer of forms regular rules,such as cotton balls are“Manganese Ball”.Fourier transform infrared spectroscopy(FTIR)and scanning electron microscopy(SEM)analysis showed that the composition of the surface of the filter medium contained iron manganese oxide and microbial composition.With the increase of the depth of the filter layer,the particle size of the manganese ball decreased gradually no rules.The high-throughput sequencing technique was used to analyze the distribution characteristics of bacterial communities in different filter layers.The results of the classification analysis showed that the contents of the cells were Firmicutes,Proteobacteria,Acidobacteria,Bacteroidetes,Actinobacteria,Verrucomicrobia.The results showed that the abundance of Bacillus sp.Microbes was 91.19%,82.83%,87.28%,respectively,which indicated that the Bacillus sp.In the biofilter for the dominant microbes.The microbial ecosystem constructed in the filter tank tends to be stable,so as to realize the efficient removal of iron and manganese. |
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