Nguyen Trong Quang creator Samorn Muttamara Chairperson Chongrak Polprasert Examination Committee Shin, Hang-Sik Examination Committee The Government of France Scholarship Donor text th Bangkok Asian Institute of Technology 1986 continuing eng 74 p. An aerobic tapered fluidized bed reactor was operated to study its performance at variable organic loading rates.It was to be measured in terms of organic removal efficiency and dissolved oxygen concentrations maintained in the reactor. The uniqueness of this process is the combined activity of suspended and attached growth microorganlsms ln or anic removal. Attached lcroorganisms were pre omlnan ln the fluidized sand media while suspended microorganisms were dominant in the volume above the expanded bed in the reactor. The investigation shows the moderate organic carbon removal efficiency (55-65 %) at medium dissolved pure oxygen of 16.9-18.6 mg/l and low detention time of 6 hours. It is deduced from the study, that the removal efficiency is dependent upon the initial waste strength, the influent dissolved oxygen and the reator sizes. A research study submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development Thesis (M.Sc.) - Asian Institute of Technology, 1986 Sewage Purification Biological treatment Factory and trade waste Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B19626 http://203.159.5.9/ait-thesis/detail.php?q=B19626 011298 20260818223900.0