A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science of the Asian Institute of Technology, Bangkok, Thailand.

Thesis (M.Sc.) - Asian Institute of Technology, 1976

A pilot plant consisting of series and dual media filters was operated discontinuously at a filtration rate of 0.15 m3 /m2-h under the average raw water turbidity of 45 JTU. The filters used were the coconut fiber - burnt rice husk series filter, burnt rice husk - sand series filter, burnt rice husk - sand and coconut fiber - burnt rice husk dual media filters. It was found that the burnt rice husk - sand dual media filter with the discontinuous operation could produce good quality water suitable for drinking purpose in term of its clarity and bacteriological content for a period of about 2~ months. Odor and anaerobic condition prevailed in the coconut fiber - burnt rice husk series and dual media filters. Due to the high head loss build up rate, the burnt rice husk was not suitable to be used as a roughing filter medium in the series filtration system. Preliminary study on the turbidity removal performance and head loss development of these filters operated continuously at a filtration rate of 0.15 m3 /m2-h but slowed down during the night time (16 h) were also conducted.