An investigation of greywater onsite reuse potential in an arid environment

Wastewater originating from bathtubs, showers, hand basins, kitchen sinks, dishwashers and laundry machines is usually not as heavily polluted as toilet water and is thus given the name greywater. Greywater separation for onsite reuse has often been voiced as a viable option, particularly for areas suffering from water scarcity. Such areas include remote arid areas, such as desert cities and arid coastal zones. However, issues related to consistency in the quality and quantity of generated greywater were listed as challenges hindering the adoption of greywater reuse. Thus, the objective of this study was to characterize the different greywater sources for variations in the quality and quantity of greywater in households in the city of Al Ain, UAE over a period of 3 months. Samples were collected from 10 Households and tested for the typical water quality parameters (pH, turbidity, COD, and TDS). In addition, a questionnaire was designed to get an estimate of the greywater flow in the different households. Results indicate that the average daily greywater production was around 88 L per person per day. Even though the results of the water quality analysis for light greywater sources (laundry, showers, and hand basins) exhibited high variability, it was still suitable for direct irrigation. The quantification of greywater flow and potential water savings indicated that greywater could be sufficient for onsite reuse in non-crop irrigation in some of the households.