Brackish water desalination for remote communities
Providing reliable, clean water to all is one of the greatest engineering challenges of our time. Potable water scarcity disproportionately effects economically impoverished populations around the world. Currently, many remote communities rely on drawing water from sources that are often contaminated with bacteria, chemicals, or dissolved salts. Hence water typically requires purification or desalination, capabilities which are often lacking in remote communities.
Solar photovoltaic reverse osmosis (PVRO) systems are a stand-alone water desalination system that can help alleviate some of the potable water scarcity challenges in low resource settings. PVRO systems can be developed using modular design approaches from commercially available components and configured to local conditions (e.g. solar insolation, temperature, water characteristics). However, affordability, design expertise and skill-operator intervention are among the factors often lacking in remote and low resource communities.
This research is developing computer-based methods to aid in the design of PVRO systems, which are tailored to the needs of these communities. The methods take local climate and water information to configure a PVRO system, associated pre-treatment, and operational strategies to ensure low-cost and long operating life. Systems developed using this work have been field tested in the Yucatan Peninsula. This work is conducted in conjunction with Fondo para La Paz (Yucatan Peninsula, Mexico) and PVPure (Yucatan Peninsula, Mexico) with funding from the W. K. Kellogg Foundation (Battle Creek, Michigan, USA) and Canada’s National Science and Engineering Council (NSERC).
Aquaculture aeration for resource constrained settings
Aquaculture is a major economic contributor in many low-income countries. For example, fish farms constitute about 5% of the GDP of Bangladesh. Improving aquaculture pond water quality holds considerable potential to increase fish yields, raise incomes, and improve food security. While aeration has been used to significantly improve water quality and increase yields, the cost of related equipment and the need for electrical power inputs has limited its use in low-income countries (LICs).
We are developing a novel method of aeration, which does not require electricity, has low maintenance requirements and can be cheaply deployed. The idea exploits the aquaculture pond two-layer structure, where the top layer is warm and oxygen rich (as the plant matter in the water generates oxygen during the daytime) while the bottom layer is cold and oxygen depleted. Our system passively mixes these layers to improve the overall oxygen content of the aquaculture pond. Preliminary lab studies have shown that this approach can improve oxygen content by approximately 30%, and we work to determine its efficacy in the field.
This project is a collaboration between the University of Toronto, NISTPASS in Vietnam, and BRAC in Bangladesh. Funding for this project has been provided by Grand Challenges Canada (http://www.grandchallenges.ca/), which is itself funded by the Government of Canada and is dedicated to supporting Bold Ideas with Big Impact in global health.