High Ammonia Wastewater Treatment Using Biological Contact Oxidation Process And Development Of The Microbial Agent

The deficiency of water resource and water pollution affected China for a longtime, and the Eutrophication caused by high ammonia concentration has attractedmore and more attention. In recent years, biological nitrogen removal process hasbeen widely used. In this study, nitrifier（ND-7） was inoculated to biological contactoxidation reactor, and the effect of nitrogen removal was discussed. In order to avoidthe microbial agents added in the activated sludge varying or becoming edominant inthe practical application, it needs pure microbial agents. The actual sewage quick startor sudden water pollution accidents both need a large number of agents. Thus, it isnecessary to study the mass and economical cultivation technology of microorganism.The core of biological contact oxidation is the carrier, which affects the treatmentefficiency of wastewater. In this study, elastic carrier, biocube sponge carrier, andsuspended carrier were used as biofilm carrier to study aeration efficiency andbiosorption ability. Dynamic tests were used in this paper to investigate the effect ofdifferent pack to the treatment of pollutant, thus provided basis for packing selection.Results showed that: the increasing sequence was elastic carrier, suspended carrier,and biocube sponge carrier according to the degree of influnence of carrier to aerationefficiency, and biocube sponge carrier, elastic carrier, and suspended carrier accordingto the degree of influence of carrier to biosorption ability. In the dynamic experiments,the start time of elastic carrier, biocube sponge carrier, and suspended carrier reactorswere11d,13d,18d, respectively. The removal efficiency of organic were93%,84.79%,62.90%, the removal efficiency of nitrate were94.88%,86.34%,67.54%andthe removal efficiency of total nitrogen were93.56%,84.65%,65.51%. Thus, elasticcarrier was optimal because of its well function of air distribution ability and biofilmactivity. Besides, its removal effect of pollutant was the best.Elastic carrier was put into reactor and the treatment of biofilm reactor to highammonia wastewater was studied. The influence of HRT, DO and C/N ratio to thetreatment effect of bio-contact oxidation was investigated. Results showed that theoptimal conditions were HRT of6h, DO of3mg/L, C/N ratio of3. At the optimalconditions, the stable COD and ammonium removal efficiency were above83%and82%, and the removal efficiency of total nitrogen was around80%. The study on economical medium and the optimal cultivation condition showedthat ND-7could use the the suitable carbon source and nitrogen source to increase theyield rate. Under the optimal conditions, the yield of ND-7could reach1.85g/L,which was higher than that cultivated by the traditional medium, and the cost droppedto0.027RMB/g.