Assessment of AquaMats for removing ammonia in intensive commercial Pacific white shrimp Litopenaeus vannamei aquaculture systems

摘要

AquaMats are high surface-area polymer filters whose use produces higher yields with reduced health risks for the aquaculture product. We used AquaMats in pilot-scale systems and in intensive commercial Pacific white shrimp Litopenaeus vannamei production systems to stabilize and improve water quality by removing ammonia. In the pilot-scale systems, evaluation of the effects of temperature and hydraulic retention time (HRT) on ammonia removal rate indicated that the surface total ammonia nitrogen (TAN) conversion rate (STR, mg TAN/m(2)-day) increased with increasing temperature and decreasing HRT. The highest STR of 319.8 mg TAN/m(2)-day was observed at a temperature of 30 A degrees C and a HRT of 5 min. In the commercial shrimp production systems, ammonia levels were significantly greater in the control systems (without AquaMats) than in the treatment systems (with AquaMats) after 6 days (P < 0.05). Results suggested that eight 150 cm x 90 cm pieces of AquaMats (0.057 m(2) surface area per m(3) culture volume) were sufficient for promoting nitrification in this system. The growth rate of juvenile shrimp was most enhanced in treatment C (with 12 pieces of AquaMats, 0.085 m(2)/m(3)), which exhibited a significant decrease in ammonia.