Study On The Treatment Of High Concentration Ammonia Nitrogen Wastewater By Immoblilized Microorganism

Immobilized microbial technology is a new technology attracting much attention in recent years.It has the advantages of large specific surface area,high volumetric load and strong impact resistance.In the treatment of ammonia-nitrogen wastewater by immobilized microorganisms,it is found that the accumulation of nitrite nitrogen can be achieved and the application of short-range nitrification and denitrification technology can be promoted.Based on the laboratory preparation,the difference between mechanized batch preparation and the former is found by comparing with the former.The control of temperature,stirring speed and other parameters are used to ensure the stability of preparation.Finally,the batch production line of immobilized microorganism is successfully established.In addition,the performance of immobilized microorganisms prepared in batch was characterized by SEM.The results showed that the immobilized microorganisms had well-developed interstitial structures and enough space for the growth and multiplication of microorganisms.The specific surface area was about 12,13m2/g.The density of immobilized microorganisms is slightly higher than that of water,which can be fully contacted with wastewater through aeration and can be applied to fluidized bed technology.In batch preparation,it was found that the mechanical preparation of immobilized microorganisms and hand-made have some differences,through further research to determine the appropriate range of parameters for the subsequent use of the reference.The results of the pilot test showed that if the nitrite nitrogen accumulation is to be achieved,certain conditions are required for the ammoxidation of the bacteria after embedding,and the optimum temperature is above 25 ℃,the best DO value is about 5mg/L and the pH value is 7-9.The initial concentration of ammonia nitrogen suitable for immobilized microbial treatment is below 400mg/L.On the basis of previous studies,the pilot plant operation of immobilized microbial treatment of ammonia nitrogen wastewater from a plant was carried out.After the commissioning and running,after the system is stabilized,the immobilized microorganisms can treat the ammonia nitrogen wastewater with the influent concentration of 120-220mg/L well,the removal rate of ammonia nitrogen is stable at about 85%,and the accumulation rate of nitrite nitrogen is about 60%.Under the premise of meeting the plant discharge requirements,the suitable maximum ammonia nitrogen load is about 0.37kg/(m3·d).The results show that immobilized microorganisms can complete the accumulation of nitrite nitrogen in the treatment of ammonia nitrogen wastewater and achieve good denitrification effect.