Study On The Embedding Method Of Heterotr-ophic Nitrification-aerobic Denitrification S-trains In Wastewater Treatment

As the new nitrogen removal method was studied in a deep-going way, a number of high efficiency nitrogen removal bacteria have been paid more and more attention. But because of the defect of microorganism preparations, such as the difficulty of transportation,the strictness of Preservation Condition and the short guarantee period, the use of the bacteria was restricted. Immobilized microorganism technique provided a new idea for the microorganism preparation. Embedding is studied the most in all the immobilization methods. The purpose of this paper is to study embedding methods that was suitable for the bacteria of our laboratory.WXZ-2,WXZ-8,WXZ-9,WXZ-15,WXZ-17 bacteria were chose to serve as the study by heterotrophic nitrification and aerobic denitrification ability. The five bacteria were discovered the law that the nitrogen was removed in the process of nitrification, the transformation was NH₄⁺-N NH₂OH N₂O N₂. The agar-PVA and CA were chose for further study in six methods by experimental comparison. In the process of the agar-PVA study, it was discovered that the best RPM of the five embedding bacteria were 180r/min. it was higher than the non- embedding bacteria. In the best Cultural Conditions, the NH₄⁺-N&TIN removal rate of the WXZ-2 embedding bacteria is 96.9%&96.5%, the NH₄⁺-N&TIN removal rate of the WXZ-2 embedding bacteria is 95.8%&95.9%, the removal rate of the two kinds of the embedding bacteria were higher than the non- embedding ones. The NH₄⁺-N&TIN removal rate of the WXZ-9 and WXZ-15 embedding bacteria were close to the non-embedding ones, the best TIN removal speed of the two kind of the bacteria were 10.1 mg/(L·h)å'Œ6.1 mg/(L·h), it was faster than the non-embedding ones. The NH₄⁺-N&TIN removal rate of the WXZ-17 embedding bacteria is 86.7%&88.1%, it was worse than the non- embedding one. The paper studied the mixed bacteria embedding, the result was that WXZ-2+ WXZ-8 and WXZ-2+WXZ-15 were the two best group. The NH₄⁺-N&TIN removal rate of the two best group was close to the non-embedding ones. but the best NH₄⁺-N&TIN removal speed of the two group were 16.9 mg(/L·h)å'Œ18 mg(/L·h).It was faster than the single. The agar-PVA had high mechanical strength and surface area, it was suitable for fluidized bed reactor. The NH₄⁺-N&TIN removal rate of the WXZ-9 agar-PVA embedding bacteria could keep 80% above in the normal temperature and dryness Preservation Condition after 6 months. The NH₄⁺-N&TIN removal rate of the five CA embedding bacteria could keep 90%. The CA method is cheaper than agar-PVA and the preservation activity were almost the same. The CA had the simple production and Cost-effective, it was suitable for activated sludge process.