Design of Solar Powered Greywater Treatment Unit for Residential Applications

Many countries around the world depend primarily on seawater desalination process which is an energy-intensive process and incorporates high electricity consumption. In United Arab Emirates (UAE), desalinated seawater accounts for almost 89.9% of the country’s water needs. The average residential water consumption is 550 liters per capita per day which is almost 82% higher than the world average.

This paper aims to design a greywater treatment plant which is fully powered by solar photovoltaic (PV) panels. The proposed water treatment plant consists of a three-step filtration process to treat greywater. Initially, the collected greywater from households is pumped to a multimedia filter to reduce the level of turbidity followed by pumping the water at high pressure through Reverse Osmosis unit and finally passing the water in the chlorination chamber to remove odor and prevent microbial growth.

The proposed system was implemented to the case study of a villa community located in Dubai which comprises 38 villas and accommodates a total of about 152 residents. The proposed water treatment plant has a capacity of producing about 83 m³ of clean water per day at a high recovery rate of 67%. The solar system proved to be efficient by providing energy of 57397 kWh which was enough to power entirely the greywater treatment plant.

Cost analysis was carried out to assess the economic feasibility of the proposed plant. The system resulted in a tangible reduction in carbon dioxide emissions of 204 ton/year.