Advanced technologies for municipal wastewater purification: technical and economic assessment

The water resources of Kuwait are limited to desalinated water to meet the requirements for all freshwater needs, unreplenishable brackish water as a supplementary source for blending and agriculture, and municipal wastewater which is treated and mainly discarded to the sea. Limited quantities of the treated effluents are utilized for agriculture and greenery purposes. The large quantities of treated effluents have a great potential to replace the brackish water supplies and to redress the balance of demand for irrigation water. Research work was carried out at the Kuwait institute for Scientific Research (KISR) to assess the technical viability and economic feasibility of implementing reverse osmosis (RO) technology to renovate Kuwait's treated wastewater effluent. This paper describes the adopted treatment, alternative pretreatment, characteristics of the permeate and cost of the renovation treatment. The results indicate that municipal wastewater can be treated by advanced technologies to produce an excellent water which is almost devoid of salts, pollutants and microorganisms. The total cost of such treatment is estimated to be almost half of the distillate cost produced by multistage flash (MSF) plants, whereas the cost of treating the tertiary treated wastewater alone by additional advanced treatment constitutes only 25% of the MSF distillate costs. The Government of the State of Kuwait has decided to implement this technology in constructing a wastewater treatment and reclamation plant at Sulaibiya in the context of privitization to produce an effluent of a quality that can be considered an additional water resource for non-potable uses.