Bamayi, Wladimir Askinin creator Vigneswaran, S. Chairperson Chongrak Polprasert Examination Committee Fude, I. Examination Committee ASEAN-USADA Scholarship Donor text th Bangkok Asian Institute of Technology 1983 continuing eng 57 leaves : ill. The study is performed to find a suitable low cost system for the treat- ment of domestic sewage. The possibility of using anaerobic filter, rotating biological disk and their combination was studied. From the anaerobic filter performance at varying hydraulic loading rates (1.41, 1.764, 2.45 m3/m2.d), it was found that beyond a hydraulic loading rate of 1.764 m3/m2.d, the COD removal efficiency was not satisfactory. The filter depth of 120 cm (2-2.5 cm broken stone) was necessary to achieve a reasonable COD removal. The RBC performance at different hydraulic loading rates (0.03, 0.06 and 0.12 m3/m2·d) indicated that the removal efficiency lies in a range of 72 to 82%. The detailed capital and operational and maintenance cost calculation also favour the RBC compared to the AF and the combination of RBC and AF. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering Thesis (M.Eng.) - Asian Institute of Technology Water Purification Filtration Filters and filtration Asian Institute of Technology. 291098 20260818090150.0