Design, construction and evaluation of an ablution water treatment unit in Oman: A case study

In arid and semi-arid countries, there is a need to identify alternative sources of water and develop appropriate technology to harness them. Greywater can be a cost-effective alternative source of water. Collection of greywater from households requires dual plumbing to separate greywater from blackwater. This constraint does not exist at most mosques, where a significant quantity of ablution water is produced in Wudhu (ablution) rooms with plumbing to separate the ablution water from blackwater. Commercial greywater treatment systems are too expensive to treat ablution water produced at most mosques, because the quantity of water produced is usually less than 2 m 3 per day. Therefore, a cost-effective, low maintenance treatment system, WWW - Wudhu Water Works - has been designed to collect, treat and reuse ablution water from small to medium-sized mosques. The system includes a sand trap, an ablution water collection tank, a filtration unit, chlorination chute, and treated water collection tank. Treatment and reuse is automated using submersible pumps and timers. Details of the design, construction and performance of the WWW are presented in this paper. The treatment unit improves used ablution water quality to acceptable limits for irrigation, and has a favourable internal return rate (IRR) of 14.9%.