DESIGN AND FABRICATION OF A WATER PURIFICATION SYSTEM

The study set out to design and fabricate a functional water purification system. The objectives were to produce a workable design, carry out fabrication of the unit, and verify performance through leak testing. The treatment sequence was arranged in three stages: a sand and gravel bed to remove suspended matter, an activated carbon cartridge for adsorption of residual contaminants, and an ultraviolet chamber for terminal disinfection. The unit was designed to supply 150 litres of treated water daily in a 6-hour cycle, corresponding to a flow of 25.0 litres per hour, driven only by a gravity head of 1.00 metre. The main design parameters included a plan area of 0.111111 m², a sand layer of 0.25 m over 0.10 m of gravel, an empty-bed contact time of 1.8 minutes in the carbon filter, and an ultraviolet exposure time of 28.8 seconds. Hydraulic analysis showed total head losses of 0.1645 m when clean and 0.2313 m at the fouled allowance, leaving available headroom of 0.8355 m and 0.7687 m respectively. Construction followed prepared engineering drawings and a bill of engineering measurement and evaluation, with the finished frame capable of supporting a wet mass of about 145 kg. The project provides a low-cost and maintainable solution to domestic water purification. The key recommendations are to increase the unit height to improve driving head, install a small booster pump after the carbon cartridge, monitor pressure across the cartridge to guide maintenance, extend the sand and gravel depth to prolong service life, add a flow control valve after the ultraviolet chamber, and provide solar-assisted backup power to guarantee uninterrupted disinfection.