Prospects of Water Desalination for Agricultural Use

Population growth along with climate change will cause the water scarcity to become the main bottleneck of sustainable agriculture in the world. So as a rough estimation, by 2030 nearly 40 billion cubic meters more water is needed annually in our country. Saline groundwater and seawater are abundant and reliable water resources which need to be desalinated for use in most agricultural activities. Cultivation of most agricultural products is currently not feasible with desalinated seawater due to high energy and capital costs. Current seawater desalination energy consumption rate is 5 kwh/m3 which stand far above minimum theoretical limit namely 1 kwh/m3. Application of desalinated water in greenhouses cultivation is being investigated. Various routes which are being investigated to reduce the costs are dealt in this paper: Innovative nanotechnology and biotechnology methods are under development for abatement of energy loss in reverse osmosis membranes. Membranes containing carbon nanotubes or proteins extracted from salinity tolerant plants are fabricated in this regard. Appropriate combination of reversed osmosis (RO) with forward osmosis (FO) is under investigation. At the same time, design of desalination plants is improved to enhance energy recovery. Utilization of solar energy in desalination is also emerging.