Desalination of brackish water using dual acting solar still

Desalination of brackish water is a very suitable approach to augment the exponentially increasing fresh water demands due to uncontrolled population growth in developing countries. Keeping in view the local needs of small families residing in remote areas of the country and having no access to fresh water availability, therefore, this research has been carried out for the development of locally fabricated dual acting solar still for desalination purpose. The system consists of a flat plate collector, an evaporation chamber equipped with heat exchanger made of copper tube, 60 Wp solar photovoltaic (PV) panel, glass roof and water circulation mechanism. The designed system works both actively as well as passively due to glass roof cover and black base plate of evaporation chamber. The result shows that the fresh water production was found to be 3.8 l/m(2) in 8 hours a day in summer, when the average solar radiation usually ranges from 750 Wm(-2) to 800 Wm-2. The daily mean collection efficiency of the desalination system was observed to be 38% at mass flow rate of 0.0035 kg/sec. Drinking quality water tests have also been performed and compared with international standards. The result shows that EC, pH, TDS, Na1+, Ca2+ and Mg was found to be 0.15 dsm(-1), 6.1, 105 ppm, 0.47 mg/l, 0.65 mg/l and 0.54 mg/l respectively and at par with international standards. The cost per liter of fresh water was $0.03, which indicates the feasibility of proposed system. The result showed that dual acting solar still can be used for desalination purposes under favorable climatic condition.