Design, Development, and Assessment of Lake Water Purification System Through Solar Concentration Technique

Abstract

This water purification system is designed by contemplating the water shortage faced by the urban areas during summers and the use of polluted lake water by the local farmers for irrigation while paying close attention to the economic factors and feasibility associated with this process. The presence of heavy metals, phosphates, nitrates, and Escherichia coli in the lake waters of the urban areas render it unfit for domestic use and irrigation. The crops cultivated utilizing these waters are hazardous, when ingested by humans and cattle, this may lead to bioaccumulation. The system designed aims at purifying the lake water, solely using solar power, chemicals, and natural filtration techniques. The experiment was conducted at New Horizon College of Engineering, Bengaluru, Karnataka, India (latitude12° 93′ N, longitude 77° 69′ E). The system uses flocculation, adsorption, micro-filtration, and distillation to purify the water. Novel integration of a Fresnel lens and a thermoelectric cooler in the solar distillation unit has improved the rate of distillation and efficiency. The distillate obtained could later be exploited for domestic purposes. An efficiency of over 78% was achieved for mercury removal, while the other polluting parameters were on par with the lake water standards set by the lake development authorities in Bengaluru, Karnataka, India. As for the solar distillation unit, the experimental results in comparison with other researches show that, the distillate output increases by coupling a Fresnel lens concentrator and a thermoelectric cooler to over 57%.