REMOVAL OF AMMONIUM-N FROM A RECIRCULATION AQUACULTURAL SYSTEM USING AN IMMOBILIZED NITRIFIER

S.K. Kim, I. Kong, B.H. Lee, L. Kang, M.G. Lee, K.H. Suh-2000

Aquacultural Engineering, 21 (3): 139-150 (from Current Contents)

Abstract:

Various immobilization methods were evaluated for the removal of ammonium-N from recirculating aquacultural water. Ba-alginate, Ca-alginate, carrageenan, and agar beads were prepared with nitriefer consortium from the activated sludge of a sewage treatment facility in Sooyoung, Pusan, South Korea. Batch bioreactor tests for the determination of the effectiveness of the immobilized nitrifier and the optimum hydraulic retention time (HRT) were carried out. The nitrifiers immobilized in Ba-alginate and Ca-alginate showed the most effective nitrification, while those immobilized in the carrageenan and agar beads showed reduced activities. Ninety five percent of the ammonia (20 mg/l) added to the batch bioreactor was nitrified in 6 h when immobilized Ba-alginate or Ca-alginate nitrifiers were used. In order to apply the immobilized nitrifier to an aquaculture facility, a continuous bioreactor was used with synthetic aquacultural water containing 2 mg/l ammonia. Using immobilized Ba-alginate and Ca-alginate beads, 94 and 87% of loaded ammonia were removed within 3.4 h of HRT, respectively. The amounts of ammonia removal per day were in the range of 2.5-82 g ammonia/m(3) per day depending on HRT. The highest ammonia removal rate of 82 g/m(3) per day was observed when HRT was 0.3 h (18 min).

(Pukyong Natl Univ; Dept Biotechnol & Bioengn; Pusan 608737; South Korea, e-mail: skkim@dolphin.pknu.ac.kr)

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