Studying on the Treatment of High Salinity Concentration Wastewater from Shrimp Farm by Floating Constructed Wetlands (FCWs) Models: Effect of Plant Cover Area

This study was processed to investigate FCWs systems' performance cultivated by native plants for treating high salinity level of shrimp farm wastewater. Three circular FCWs models (pond 1; pond 2; pond 3), which had 10 m2 in surface area and 1 m in depth, were operated in 45 d period. The pond’ surface was covered of 0 % (pond 1), 20 % (pond 2), and 40 % (pond 3) by native plant species as Scirpus littoralis Schrab,Cyperus alternifolius, Paspalum vaginatum with the same area ratio for each plant in the ponds. The influent and effluent flow rate was 1.67 m3 d-1, the hydraulic retention time was maintained at 6 d during the experimental period; the obtained result revealed that the FCWs model, which covered by 20 % of plants on the surface, displayed the maximum removal was 77.8 % for BOD5; 84.0 % for COD, 96.2 % for NH4+ - N; and 89.4 % for TN. It was also observed that the more cover area on the surface of the pond, the less development of the algal community in the pond body. It is concluded that the FCWs model covered by native plants is feasible for the treatment of shrimp’s farm wastewater. The coverage of 20 % is suggested for the establishment of floating constructed wetlands.