Pilot study on renovation of subsurface water using a reverse osmosis desalting system

Like many cities of the world, Kuwait has seen a continuous rise in the sub surface water table. The impact of the water rise is manifested in flooded basements, surface pending of water, cracks in buildings and damaged roads. A study carried out by the Kuwait Institute for Scientific Research (KISR) recommended drainage by deep wells to lower and maintain the subsurface wa ter at a desired level. A large quantity of water needs to be permanently p umped for this purpose. Disposing of the pumped water as waste is a loss th at Kuwait cannot afford in view of its meager, over-stressed and practicall y non-renewable natural groundwater resources. Since the quality of the pum ped water is likely to prohibit any direct use, it is proposed to reduce it s salt content using reverse osmosis (RO) technology. The desalinated water can then be used for lawn-watering, thus saving on the use of brackish gro undwater supplied from other sources. RO is being used for desalting a vari ety of feedwater, but its use with subsurface water has not been investigat ed before in Kuwait. This water is different from natural groundwater in th at it is partially contaminated. However, before large-scale implementation , it is essential to evaluate the performance of RO with the special bioche mical characteristics of subsurface water. This paper outlines the result o f a pilot plant study carried at KISR to investigate the viability and tech nical feasibility of using two types of RO configuration systems (i.e., SW and HFF) to desalinate subsurface water. The results indicate that both sys tems have technical and economic merits and can produce freshwater of high quality for agriculture, lawns and for emergencies at comparatively low cos t.