Study On Bioremediation Of Urban Surface Water By Novel Biofilm Reactor

Aiming polluted surface water, people have taken many methods to remedy it, the biofilm has high efficiency for remediation of surface water among them. The biofilm carrier is usually relative to its activity. Ceramic particle was mainly used for biofilm carrier and remediation of surface water, however, there are some problems of it, such as flow situation, washing back and the complex structure, inconvenient operation and management. A kind of ceramic honeycomb carrier was used for biofilm carrier and novel reactor was designed based on carrier, which was used for remediation of polluted urban surface water in this project.Properties of biofilm formed and growth on ceramic carrier were discussed under different condition. The experimental results indicated that ceramic honeycomb carrier was propitious to biofilm's forming and growing. Influence of hydraulic resident time (HRT) on NH₄⁺-N removal rate was studied at first, then the best HRT was determined based on the experiments. The removal rate of NH₄⁺–N,TP,COD_Cr,TOC,NO2–-N and turbidity were 82.8～95.8%, 2.11～45.6%, 4.3～56.7%, 6.6～37.7%,26.1～60.3% and 82.8～95.8% respectively under HRT of 50 min. Furthermore, the removal rate of U254 were 3.7%～35.7%. The reactor was connected with anaerobic ceramic filter tank and used for treatment of surface water and the TN can be removed. Effect of several factors on ammonia nitrogen removal were discussed.Abundant microbiology formed on the carrier due to the special structure of ceramic carrier and the surface water according to experiments. The microorganism attached on the carrier easily, and honeycomb shape promote oxygen transfer, which is main reason why ammonia nitrogen removal with high efficiency according to analysis.Based on bench scale, the reactor was enlarged on pioneer scale in order to supply the dada for practice. The reactor was also compared with fluidized bed reactor for their biofilm form and ammoniac nitrogen removal. The results indicted that the novel reactor has the property of better water qualify and lower drive power.The reactor was also extended to treat the wastewater with high concentration of ammonia nitrogen and the effluent from municipal wastewater treatment plant respectively and it's removal efficiency on ammonia nitrogen is relatively high.The novel reactor has wide application in the bioremediation of surface water according to the experiments.