Abstract
Greywater is the term given to all used water discharged from a house includes shower, bath, hand basin, kitchen sink, dishwasher, washing machine and laundry tub water except for toilet water. To cope with the current and future water scarcity in Saudi Arabia, we need to look for alternative water sources and work towards achieving high level of sustainability. One such alternative is the reuse of domestic greywater for irrigation around homes. The greywater reuse practice is becoming increasingly common in many households around the country, but there are no in-depth studies that provide a clear understanding of how the greywater reuse impacts on soil, plant and human health in the long-term. Furthermore, the re-use of greywater for garden irrigation or in flushing system should be encouraged in urban and rural households as it utilizes a valuable on-site resource, conserves precious drinking water and reduces the load on wastewater disposal systems. This paper covers a simple system for treatment of greywater generated from hand and mouth wash (ablution) basin in mosques in Saudi Arabia. The proposed system contained sand and activated carbonic filters along with simple sterilization (Ultra Violet unit) for removing the pathogenic microbes and other impurities may found in the Greywater. The suggested system was tested in a big mosque (Othman bin Affan Mosque) - Riyadh, Saudi Arabia. The obtained results indicated that the concentration of ((Ca2+, Mg2+, Na+, K+, HCO3-, CO32-, Cl- and SO42- in gray water were relatively not changed than tab water. However, by using the tested system the concentrations of the studied ions became more or less the same as in tap water, especially at the final stage of water purification (after passing the water through the U.V. unites) but it is very efficient in treating the microbial content after the treatment. It's needless to say that such purified water could be successfully re-used for flushing toilets or irrigating all kinds of crops (as grass and palms) which are sensitive and /or resistant to salinity.