Low-cost Desalination System

Abstract

This research aimed to find a low-cost solar desalination system using evaporation and condensation phenomena to treat the polluted water, and check if the collected water meets the World Health Organization (WHO) drinking water standards. Initially, several evaporation units were tested to achieve high water temperature (above boiling point). The flat solar panel (FSP) achieved the highest outlet temperature; however, it was not enough as an evaporation unit. Single solar still was found effective to evaporate and condensate the polluted water to get clean water. It was found that adding mirrors as internal reflectors, jute wick, and gravel to maintain the heat increase the output. Coupling it with FSP further increased its efficiency achieving the highest output and obtained an average of 1193±289.94mL. The FSP acted as a preheater to the solar still, while the single basin single slope solar still was the evaporation and condensation unit. Polluted groundwater was mimicked and used to check the performance of the final system, also mass and heat balance were obtained. In terms of physical and biological analysis (E. coli or total coliform) analysis, the parameters were below the WHO standards; however, for chemical analysis, the average ammonium concentration increased, and potassium and nickel decreased but remained above the WHO standards. Additionally, life cycle assessment was performed to see the impact on the environment, the solar still (SS) had a higher impact than FSP in almost all categories. Additionally, the product's contribution to the environment was checked for global warming, stratospheric ozone depletion, and ionizing radiation, plywood had the highest contribution in all of the categories and had the highest contribution in the last two categories for FSP. Steel in FSP contributed the most in global warming. Moreover, the cumulative energy demand (CED) was found to be 130.2MJ/unit of SS and 44.43MJ/unit of FSP, this difference is due to the different input in producing 1 unit. Furthermore, since FSP was found very effective at heating water, it was used in gravity solar heater as a low-cost disinfection method. It was observed that gravity solar heater with the copper tube heat exchanger eliminated 100% of E. coli and total coliform meeting WHO drinking water standards.

Date of Award	Dec 2022
Original language	American English
Supervisor	Banu Sizirici Yildiz (Supervisor)