제올라이트 여재의 암모니아성 질소 이온교환 능력에 따른 ZBAF의 질산화 효율 비교

Abstract

This study was conducted to investigate nitrification by measuring the ammonia nitrogen adsorption ability of zeolite media. Zeolite adsorbs ammonia nitrogen through cation exchange. When zeolite is used as the filteration media in biological aerated filters (BAF), nitrifying bacteria can be easily attached. Using two types of zeolite that have different calcination temperatures, it was confirmed differences in nitrification rate relative to the ammonium ions exchange capacity of the zeolite media. The strength of the zeolite media was higher as calcination temperature was higher, while BET specific surface area was decreased. The ammonia nitrogen adsorption of the zeolite media at 600℃ was higher than at 900℃, but nitrification rates were similar when either media was used for the zeolite biological aerated filter (ZBAF). During the entire operation period, the 600℃ zeolite had an ammonia nitrogen removal rate of 0.31 kg/m³/d, and the 900℃ zeolite media had a rate of 0.28 kg/m³/d (p>0.05). When the influent was held on shutdown for a month and processing began again, the nitrification rate of the ZBAFs showed a similar amount of NO_x-N (sum of the concentration of nitrite and nitrate nitrogen) production within two days of reoperation that was similar to the rate before shutdown. The effect of water temperature had little effect on rate. Ammonia nitrogen removal by ZBAFs was maintained in water temperatures as low as 5℃. However, the ammonia nitrogen removal and nitrification rate were decreased in 600℃ zeolite media after 3 months of operation because media’s morphology changed.