A Thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering, School of Environment, Resources and Development

Thesis (M.Eng.) - Asian Institute of Technology, 1989

Groundwater is extensively used for drinking purpose in rural areas in many developing countries. Although it is one of the safest source of drinking water, it ca n be un fit for drinking purpose due to high mineral content like iron and manganese and contamination by coliform organisms. A simple filtration process without use of chemicals, consisting of Matrix filter coupled with a contact filter was studied to investigate the removal of iron and coliform. Th is study was conducted to determine the effect of various combination of coarse and fine media on the removal of iron and coliform organisms. The study revealed that t h e efficiency of a Matrix filter depends upon the size combination of coarse and fin e media. In t h is study, t h e Matrix filter consisting of 21.9 mm road s tone infilled with O. 38 mm sand was better t h an other combinations investigated for iron and coliform organisms removal . Comparative study with ordinary sand filter showed that Matrix filter has a remarkable lower pressure drop and higher storage capacity for solids than the ordinary sand filter. A pilot-scale filtration un it made from oil drums was investigated to see its suitability for rural water supply to remove iron and coliform organisms from ground water. At a filtration velocity of 0 . 7 m/h, this unit could produce filtered water with less than 0.5 mg/l of iron for 30 hours of continuous operation with an influent concentration of 4 . 0 to 5.0 mg/1.