Suwat Tanyaros creator Lin, Chang Kwei Chairperson Edwards, Peter Examination Committee Hambrey, John B. Examination committee Annachhatre, Ajit P. Examination Committee Macintosh, Donald J. Examination committee Rajamangala Institute of Technology Scholarship donor text series technical report th Bangkok Asian Institute of Technology 2001 continuing eng 168 leaves Laboratory experiments, a survey and {uFB01}eld experiment were conducted to explore the potential of the oyster Crassosrrea belcheri as a bio{uFB01}lter system and wastewater treatment in intensive shrimp culture. A series of laboratory experiments were conducted to examine the effect of water salinity on the {uFB01}ltration rate of oysters, the performance of oyster feeding on phytoplankton commonly found in intensive shrimp ponds, characteristics of suspended solid particles in shrimp pond water, and the effects of using a settling tank on nutrient removal and feeding performance of oysters. The survey examined the species composition and density of the dominant phytoplankton species in intensive shrimp pond water. The {uFB01}eld experiment examined the effect of water {uFB02}ow rate on oysters feeding on shrimp pond water in a real shrimp pond environment. The results obtained from those experiments were used to develop the basic design parameters for a treatment system, and its performance was assessed. Over a salinity range of 10-35 ppt, maximum {uFB01}ltration rates were obtained with salinities between 10 and 25 ppt for both small and large size oysters. The average {uFB01}ltration rates of both sizes of oyster were found to be highly correlated with water salinity. In a survey of 20 intensive shrimp ponds sampled throughout the culture period, 47 species of phytoplankton were identi{uFB01}ed. Dominant species and species composition was related to salinity. One group was typically found associated with salinity 10-30 ppt, and included as dominant species blue green algae Oscillatoria perornara, Chroococcus minatus and Microcystis aeruginosa; green alga Oocystis elliptica; diatoms Coscinodiscus sp. and Niztschia closrerium; and dinoflagelates Protoperidinium divergents and Gymnodinium dissimiles. The group associated with salinities >31 ppt was dominated by similar species but with different densities. The dominant species were blue green algae Oscillaioria. lemmermannii, Chorococcus minatus and Microcystis aeruginosa; green alga Oocystis elliprica; diatoms Coscinodiscus sp. and Niztschia closterium and dino{uFB02}agelates Protoperidinium divergents, Gymnodinium dissimiles and Prorocentrum micans. Different concentrations of ammonia in shrimp pond water had an effect on the dominant species of phytoplankton. When ammonia-N concentrations were $0.19 mg 1" , more than 77% of total the phytoplankton density was composed of two species, Osillatoria lemm_e A dissertation submitted in partial fulfillment of the requirements for the degree of Doctoral of Technical Science, School of Environment, Resources and Development Thesis (Ph.D.) - Asian Institute of Technology, 2001 Oysters Ponds Water Purification Fixed-film biological process Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B00345 http://203.159.5.9/ait-thesis/detail.php?q=B00345 030110 20260819085902.0