title: Comparative study of the nitrification characteristics of two different nitrifier immobilization methods.
abstract: The research investigated the nitrification characteristics of two different immobilization methods: nitrifier encapsulation in polyethylene glycol (PEG) gel pellets and nitrifier biofilm attachment on elastic plastic filler. The two carriers were placed in identical reactors. They reached a maximum nitrification rate of 39 and 25 mgN/L.h 30 days after start-up. The results showed that the nitrification efficiency in the PEG reactor was higher than in the biofilm reactor under the same conditions. Variations in temperature decreased the nitrification rate by approximately 55% in the PEG reactor from 28 to 8 degrees C, while 74.2% in the biofilm reactor. When the COD loading rate was increased to 0.8 kg/m(3) day, the nitrification efficiency in the biofilm reactor dropped sharply to 23%, and that of PEG reactor remained over 80%. PEG pellets with a high nitrification rate under all conditions showed promise as an immobilization medium, and are likely to be utilized in the nitrification of high-strength ammonia and COD wastewater during long-term operation.
authors: School of Environmental Science & Engineering, Shanghai Jiaotong University, 200240 Shanghai, China. lizr210@hotmail.com
authors: Zhirong
authors: Z
authors: Li
authors: Zhi
authors: Z
authors: Zhang
authors: Jun
authors: J
authors: Li
authors: Zhenjia
authors: Z
authors: Zhang
mesh_terms: D000641:Ammonia / Q000302:isolation & purification; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology; D018914:Cells, Immobilized; D052918:Environmental Restoration and Remediation / Q000379:methods*; D009566:Nitrates / Q000032:analysis; D009573:Nitrites / Q000032:analysis; D009584:Nitrogen / Q000378:metabolism*; D009930:Organic Chemicals / Q000378:metabolism; D013696:Temperature
chemical_list: D009566:Nitrates; D009573:Nitrites; D009930:Organic Chemicals; D000641:Ammonia; D009584:Nitrogen