Study On The Combination Of EGSB And CRI Treatment Of Low Concentration Organic Wastewater

With the development of rural economy in our country, the water pollution in rural areas is becoming increasingly serious, which not only constrains the coordinated development of rural economy and society, but also seriously endanger human health. The current state of environmental issues more and more attention to rural water, rural water pollution has become an important new task of rural development. Therefore, the study for the development of high efficiency and low consumption of rural sewage treatment technology has important practical significance. The treatment of EGSB and CRI on low concentration organic wastewater were studied.At a temperature of 12.5~28.5°C, influent COD concentration of 70~593.2mg/L, HRT of 48h~36h , using aerobic sludge as seed sludge, the startup of EGSB reactor at room temperature was studied. After 70 days the startup of reactor was completed successfully, the average COD removal rate reached above 80%. The results showed that temperature, pH, influent COD concentration, volatile acids, alkalinity were the main factors that effected the reactor's startup.According to the results of previous studies, zeolite, ceramic, river sand, quartz sand were chose initially as filter media of CRI, and the adsorption properties of filter media were determined through adsorption and orthogonal experiments. The results showed that the best pollutant adsorption equilibrium time of four different filter media on different pollutants was different. The best adsorption equilibrium time of zeolite on ammonia nitrogen, nitrate nitrogen, nitrite nitrogen and phosphorus was 2h, 30min, 20min, 2h, respectively. The best adsorption equilibrium time of ceramic ammonia nitrogen, nitrate nitrogen, nitrite nitrogen and phosphorus was 2h, 20min, 2h, 2h, respectively. The best adsorption equilibrium time of river sand on ammonia nitrogen, nitrate nitrogen, nitrite nitrogen and phosphorus was 2h, 30min, 30min, 2h, respectively. The best adsorption equilibrium time of quartz on ammonia nitrogen, nitrate nitrogen, nitrite nitrogen and phosphorus was 2h, 4h, 20min, 2h, respectively. The adsorption results showed that adsorption performance of zeolite, ceramic on the N, P is better than river sand, quartz sand. It could be seen from the orthogonal test, the greatest influence factors on the adsorption media is filter media dosage, followed by the adsorption time, the effect of solution temperature and solution pH value on adsorption of ammonia is not great.At a temperature of 26.9~31°C, HRT of 24h, 18h, 12h, 8h, 4h, the treatment of EGSB reactor on low concentration organic wastewater was researched. At a HRT of 24h, average COD removal rate was 63.0%. At a HRT of 18h, average COD removal rate was 74.3%. At a HRT of 12h, average COD removal rate was 77.4%. At a HRT of 8h, average COD removal rate was 33.1%. At a HRT of 4h, average COD removal rate was 31.8%. It could be seen, the COD removal at a HRT of 24h~12h is better than at other HRT.In the whole operation, the total average COD removal rate of the entire system could reach 84.0%, 72.4%of which was removed by anaerobic reactor. the total nitrogen removal rate could reach 53.2% on average, 22.57%of which was removed by CRI., total ammonia nitrogen removal rate could reach 70.3% on average, 25.2%of which was removed by CRI. average removal rate of phosphorus could reach 72.5%, 30.5% of which was removed by CRI. It could be seen, COD is mainly removed by the anaerobic reactor, N, P is removed mainly by CRI. Removal of the pollutants largely achieved the expected results.