Experimental Study On Advanced Treatment Of Domestic Sewage By Anaerobic Ammonium Oxidation

ANAMMOX process is the most innovative discovery in water treatment field,which is because of the advantages of saving carbon sources,producing less mud,high sustainability and high economic benefits by the wide attention of researchers.In order to make nitrogen and COD removal at the same time,we can make ANAMMOX bacteria and aerobic bacteria co-exist in anaerobic ammonia oxidation device.As oxygen and organic matter in sewage is used,it will provide the conditions for the growth of ANAMMOX bacteria.This experiment based on the principle of ANAMMOX,respectively study the following three aspects.The first is the effects of different inoculation methods on start-up time and treatment effect of the anaerobic ammonium oxidation reactors and observing the denitrification effect of the two groups after improving the reactor load.The second is to study the effect of pH,temperature and COD concentration on ANAMMOX and find out which is the most important factor to ANAMMOX.The third is the study of ANAMMOX on advanced treatment of domestic sewage under the low or high temperature condition and variation of the substrate along filter.In the first part,two biofilters were filled with volcanics.One was inoculated raw sludge from sewage treatment plant,the other was inoculated anammox bacteria.After 120 days,both of them had successfully launched and had good denitrification effect.In order to enrich more ANAMMOX bacteria in the reactor,we reduced the HRT and increased the concentration of the substrate.The two groups of the reactor have obtained well nitrogen removal efficiency in the operation of the 50 days.In the second part,the ASBR reactors within ANAMMOX mud water were used to the study of ANAMMOX rate under different pH,pH,temperature and COD concentration.We concluded that the best pH is 7.5,temperature is 30?,COD concentration is 40mg/L.Based on the results of the single factor test,we selected three appropriate levels for three kinds of influencing factors and carried out the orthogonal experiment.We concluded that the most influential factor to the ANAMMOX was COD concentration,followed by the temperature,and the pH was the least.In the third part,the two groups of ANAMMOX reactors were used in the advanced treatment of domestic sewage.One was heated to 32±2?,the other was not heated.Both of their pH was about 7.5.The removal rate of NH₄⁺-N were 65% and 75%;NO₂^--N were 80% and85%;COD were 50% and 57%,respectively.The efficiency of treatment of domestic sewage by ANAMMOX is better at high temperatures than at low temperatures.But the economic benefits were opposite.By the determination of the concentration of the substrate in different height of thefilter column,we can understand the change of the substrate along the reactor and find out the removal of NH₄⁺-N and NO₂^--N and the generation of NO3--N showed that the beginning and end were less,and the middle was more.Because of the presence of DO,the 0³0cm of the filter column was removed in large quantities.