Anammox Process Of Waste Water From Cassava Fuel Ethanol Production

In the processing of fuel ethanol production, although waste water is purified by traditional methods, there are still a large number of high nitrogen waste water, which seriously affect the water environment in our country. The higher water discharge standard of sewage puts forward new requirements to denitrification process. Anaerobic ammonium oxidation, as a new, effective energy saving, autotrophs process, with the advantages of no additional carbon source and low sludge production, achieves the shortest way of ammonia nitrogen transformation. The purpose of this study is to improve the engineering application of anaerobic oxidation reactor process in the Tianguan Group.This study compared the concentration and the removal rate of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen under the different inoculation ratio of aerobic nitrification sludge and anaerobic digestion sludge, and screened out the best enrichment method of anaerobic ammonium oxidation sludge bacteria. UASB reactor was used to deal with the second stage waste water from cassava fuel ethanol production of Tianguan Group. The most favorable conditions were selected for the growth of anaerobic ammonia oxidation bacteria, to seek the optimal control factors and operating parameters, to achieve economic and efficient treatment of low C/N ratio waste water, and to improve the process of anaerobic ammonium oxidation. Through the adjustment of the pH value and reaction temperature, the relationship of ammonia nitrogen, pH value, reaction temperature and running time were explored. Research results showed that:1. Different concentration proportion of anaerobic digestion sludge and aerobic nitrification sludge were cultured to achieve rapid enrichment of anammox bacteria in simulated ASBR reactors, with regulating the concentration of ammonia and nitrite and analyzing effluent substrate. By contrast, the reactor packed with aerobic nitrification sludge was the first to start anaerobic ammonia oxidation reaction. The one packed with anaerobic digested sludge was the longest. The starting time was prolonged with the increase of the proportion of anaerobic digested sludge. It indicated that the inoculation of aerobic nitrification sludge was more favorable for the rapid enrichment and cultivation of anaerobic ammonium oxidizing bacteria in industry.2. In 12 L UASB reactor, the active anammox sludge was inoculated, the pH value was 7.5 in influent, and the remaining temperature was 35?. By increasing the concentration of ammonia nitrogen and nitrite nitrogen in influent at different stages and changing the waste water retention time, the anammox reaction can be successful started in 70 days.3. After the UASB reactor starting successfully, the substrate concentrations were measured to analyze the removal efficiency of ammonia nitrogen every 12 h, with changing the influent pH and the reactor temperature. The results showed that the removal efficiency of NH4+-N was the best to 87.88%, when the pH value was 7.5 and the temperature was 30-35 ?, which was fit for the growth of anaerobic ammonium-oxidizing bacteria and met the industrial requirement.4. The correlation of running time, influent pH value, temperature and effluent NH4+-N concentration were analyzed by multiple regression analysis. Taking the run-time, the influent pH and the temperature as independent variables, and the effluent NH4+-N as a dependent variable, a regression equation model (R2=0.9354): y=-464.5535154+28.73789971x3-0.077251892x1x3-7.475279169x2x3 +0.010083796 x,x2x3+16.04656061x2+0.445154394x32Temperature was the main factor that influenced NH4+-N concentration, and the interactive influence of temperature and running time, temperature and pH value also affected the concentration of NH4+-N in effluent. Three variables, including run time, temperature and pH value, could explain 84.29% variation of the effluent ammonia concentration, and the remaining 15.71% could be explained by other factors. According to the different pH and temperature of Tianguan waste water, the best nitrogen removing can be achieved by adjusting running time bu using this established model.