ACM Check Dams in Concrete Gutters for Recirculation Filters of Wastewater from Whiteleg Shrimp (Litopenaeus vannamei) Aquaculture in Southern Thailand

Abstract

The research was aimed to recirculate the treated wastewater from Whiteleg shrimp farms in following each other without interruption by using concrete gutters containing ACM (Assembled Constructed Materials) check dams as the filters. Among the 2-inch diameter of chipped-assembled-constructed materials, the ACM-Brick filter was the most effective rather than roof-tile, blocked cement, and rock, respectively. Three ACM-Brick check dams with 5-m space between them were indicated as 47.3% treatment efficiency together with flow rates of 600 to 900 L/hr, and up to more 65% and 85% for fourth and fifth ACM-Brick check dams while the first and second dams found 13.0% to 28.4% efficiencies. Seemingly, irrespective of employing brick, roof-tile, blocked cement, or rock for constructing the ACM check dam was installed in concrete gutters with the size of 1-m width, 0.5-m depth, and more or less 20-m length that could be served needs in recirculation aquaculture of Whiteleg shrimps to gain satisfied benefits. Culturing Whiteleg shrimps in 3-sq.m. and 3-cu.m.concrete gutters containing only one of 0.5-sq.m. and 1-depth ACM-Brick filters by RCB design for 4 treatments (culturing shrimp densities) and 3 replications found the density of 105 juveniles/3m 2 (6,606 kg/ha) with the most harvested-added weight 2,710 kg/ha (69.55 % of beginning weight), and decreasing after increasing the density of 6,720, 8,371, and 11,382 kg/ha in corresponding to harvested-added weight 65.29%, 46.36%, and 42.33%, respectively. The findings also informed that flow rate of 720 L/hr indicated somewhat high effective influences on decreasing of water temperature, salinity, pH, DO, EC, alkalinity, TDS, BOD, NH 4 -N, NO 2 -N, and NO 3 -N which were conditioned for recirculation aquaculture of Whiteleg shrimps.