Grantee Research Project Results

2021 Progress Report: Small-Scale Solar Desalination for Drinking Water

EPA Grant Number: SU840155
Title: Small-Scale Solar Desalination for Drinking Water
Investigators: Venkatadriagaram, Sundararajan , Deuling, Ryan , Salameh, Yazan , Leon, Jose de , Gonzalez-Almacen, Aileen
Institution: University of California - Riverside
EPA Project Officer: Page, Angela
Phase: I
Project Period: December 1, 2020 through November 30, 2021 (Extended to November 30, 2022)
Project Period Covered by this Report: December 1, 2021 through November 30,2022
Project Amount: $24,995
RFA: P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet (2020) RFA Text |  Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources

Objective:

The project aims to build a desalination system that provides water supply for small communities and families that do not have access to water.  The system uses a combination of solar energy, an innovative Venturi-based vacuum system, condensation, and demisting to obtain desalination without the need for reverse osmosis.  The system will work with brackish groundwater, seawater, or reusable water that has undergone simple filtration. This system is intended for use in isolated communities in arid places such as southwestern areas of the United States where clean water is in short supply but saltwater or brackish water may be more available and where water reuse may be necessary.

Progress Summary:

The team has designed the overall process flow by doing detailed calculations of flow rates and temperatures. These designs have been validated using simulations. The team has designed, constructed and tested the Venturi subsystem. This subsystem accelerates the flow to obtain the vacuum needed to evaporate the brackish water and to entrain in a fast-moving air-stream. This subsystem is being revised to obtain adequate flow rate and pressures. The demister unit separates water droplets from the water vapor so that only desalinated water enters the condenser. The condenser uses cooling water to condense the vapor to obtain pure water. The condenser unit and the demister subsystems have been designed and simulated. They are currently under construction. Solar energy is used to heat the water and the incoming air. In addition, solar panels provide energy for the pumps and fans. Detail design of this subsystem is currently in progress.  

Future Activities:

The team will continue the construction and testing of each unit in the lab and conducting the research.  The Venturi subsystem is undergoing re-design based on initial results. Experimental validation and iteration will continue till the design is refined. For the condenser, assembly is being performed as the final parts arrive.  Once constructed, experiments can be performed to verify the design calculations.  The team will then make design revisions as needed in order to maximize the efficiency of the condensing unit when manufacturing stage is reached. The demister design is being reviewed by the new team member.  Parts will be ordered in the upcoming weeks in order to have all parts required for a working prototype.  Once assembled, the team will conduct experiments on the demister in order to ensure the system achieves the desired output. The solar subsystem is currently under design by a capstone senior design team. Construction and validation will be subsequently carried and the subsystem will be integrated with the rest of the system. 

Supplemental Keywords:

Venturi Tube, prototype testing, safe drinking water act, condenser, desalination, heat transfer, clean water, fluid flow, demister, condensation. 

Progress and Final Reports:

Original Abstract

Final Report