Providing water for livestock and crop production to a rural area in Bonaire using reverse osmosis

Abstract

Water scarcity is a serious issue on many smaller islands, with population growth and the predicted impacts of climate change as driving factors. Bonaire is a small island located in the Caribbean Sea that has rural areas without grid connections to electricity and water. Agriculture, both livestock and hobby crop farming, in the Punta Blanku region used to rely on groundwater pumped from wells. Groundwater usage had to be discontinued due to salt intrusion causing the water to become brackish. Water for a large chicken farm that supplies almost all eggs for Bonaire now has water delivered by truck, but it is not reliable due to transportation issues and costs. Reverse osmosis (RO) is recommended as a reliable way to provide water to the Punta Blanku region. Water production can be powered by renewable energy and be more economically feasible with windmill power as the electrical energy source for the RO system. Surface seawater and brackish groundwater samples were tested to determine the best water source for the RO system. Total dissolved solids and electrical conductivity values determine the total power pumping need for the RO system. Using sample results and IMSDesigns, a reverse osmosis model designed by Hydranautics, it was determined that brackish water reverse osmosis (BWRO) was preferred over seawater reverse osmosis (SWRO). With Bonaire wind speeds, FreshWaterMill can easily power 200 cubic meters permeate production per day with BWRO. Additionally, less fouling is expected for BRWO than SWRO due to prefiltration by soil.