Research On Microorganism Immobilization Technology In-situ Remediation Polluted River

Carrier selection has always been an important subject in the application of microorganism immobilization technology in the field of pollution control.To exploring purification of microorganism in-situ immobilization technology for the polluted river,the study selected 6 kinds of different types of microbial carrier,constructed microorganism in-situ immobilization system,comparative analyzed the physical characterization of different carrier and biofilm forming performance.And on this basis,investigated the purification effect of microorganism in-situ immobilization system on nitrogen and phosphorus pollutants in river.6 kinds of carrier materials,the surface and internal of zeolite(FS),volcanic rock(VR),coral sand(CS),polyurethane(PU)has abundant pore structure,to be able to load a lot of functional microbes,and carbon fiber(CF)and artificial fibers(AF)is composed of filamentous structures,surface area is great.After 6 kinds of carrier were in-situ hung membrane,average hang modulus and average biofilm thickness of three kinds of natural carrier were 0.25 g/g,25.833 mu m,average hang modulus and average biofilm thickness of three kinds of artificial carrier were 3.862 g/g,49.846 mu m,namely the artificial carrier have greater average biomass and biofilm thickness than the natural carrier,suggests that artificial carrier has better biological affinity,more suitable for microbes growth.By using high-throughput sequencing technology to analyze the community structure of 6 kinds of carrier after being in-situ hung membrane,it was found that the community structure and main functions of dominant bacteria among each carrier were quite different.On average,31.5%of the dominant bacteria in the six carriers were bacteria with the removal function of nitrogen and phosphorus.FS contained the highest relative abundance of nitrifying bacteria,28%.The relative abundance of denitrifying bacteria in AF was the highest,which was 15.8%.CS had the highest relative abundance of polyphosphates,at 11.3%.After 6 kinds of carrier were in-situ hung membrane,the pollutants degradation rates of system were higher than not hanged membrane treatment group,suggest that hang membrane treatment can strengthen the carrier of nitrogen and phosphorus removal efficiency.In 6 microorganism in-situ immobilization system,CF has the best total phosphorus removal efficiency,the highest TP removal rate was 81.0%,and the degradation rate constant and TP half-life were respectively 0.267 d-1 and 2.594 d.CS and CF had the best purification efficiency for nitrogen-containing pollutants,and the highest removal rates of TN,NO3-and NH4+ were 62.2%,65.4%,69.9%,79.8%,57.9%and 55.7%respectively.The degradation rate constant and half-life of TN were 0.133 d-1,5.212 d,0.149 d-1 and 4.625 d,respectively.The degradation rate constant and half-life of NO3-were respectively 0.203 d-1,3.415 d,0.271 d-1 and 2.558 d.The degradation rate constant and half-life of NH4+ were 0.095 d-1,7.296 d,0.091 d-1 and 7.614 d,respectively.In the natural water purification,CF materials have obvious advantages,its purification efficiency of nitrogen and phosphorus are the best,shows that the effect is stable,can effectively resist environmental impact,is a kind of excellent adaptable to the complicated natural water condition optimized in-situ microorganism immobilized carrier material.