Membrane technology for sustainable treated wastewater reuse: agricultural, environmental and hydrological considerations Gideon Oron, Leonid Gillerman, Amos Bick, Yossi Manor, Nisan Buriakovsky and Joseph Hagin ABSTRACT Gideon Oron (corresponding author) Leonid Gillerman Nisan Buriakovsky Environment Water Resources, J. Blaustein Institutes for Desert Research, Ben-Gurion University of The Negev, Kiryat Sde-Boker 84990, Israel E-mail: gidi@bgu.ac.il Gideon Oron The Department of Industrial Engineering and Management, and the Department of Biotechnology and Environmental Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel Gideon Oron Joseph Hagin The Grand Water Research Institute, The Technion, Haifa 32000, Israel Amos Bick The Department of Industrial Engineering and Management, Jerusalem College of Technology, Jerusale ´ n 91160, Israel E-mail: amosbick@walla.com Yossi Manor Central Virological Laboratory, Sheba Medical Centre, Tel-HaShomer 52621, Israel Field experiments were conducted in agricultural fields in which secondary wastewater of the City of Arad (Israel) is reused for irrigation. For sustainable agricultural production and safe groundwater recharge the secondary effluent is further polished by a combined two-stage membrane pilot system. The pilot membrane system consists of two main in row stages: Ultrafiltration (UF) and Reverse Osmosis (RO). The UF stage is efficient in the removal of the pathogens and suspended organic matter while the successive RO stage provides safe removal of the dissolved solids (salinity). Effluents of various qualities were applied for agricultural irrigation along with continuous monitoring of the membrane system performance. Best agricultural yields were obtained when applying effluent having minimal content of dissolved solids (after the RO stage) as compared with secondary effluent without any further treatment and extended storage. In regions with shallow groundwater reduced soil salinity in the upper productive layers, maintained by extra membrane treatment, will guarantee minimal dissolved solids migration to the aquifers and minimize salinisation processes. Key words | Irrigation, membrane technology, soil salinisation, sustainable production INTRODUCTION General Water scarcity in arid and semi-arid regions along with expanding awareness to environmental dilemmas has intensified the search for alternative sources. Adequate wastewater management is now a vital requirement not just an option. Treated domestic secondary effluent is a valuable extra water source that can be reused for diverse purposes, primarily for agriculture production, aquatic life preservation, and aquifer recharge. Groundwater enrich- ment with effluent is maintained primarily via Soil Aquifer Treatment (SAT) (Quanrud et al. 2003). Secondary effluent commonly contains elevated amounts of nutrients that might bump-up eutrophication processes when disposed into lakes and streams. The contained dissolved solids might jeopardize sustainable agriculture production and the groundwater quality. Advanced wastewater treatment is doi: 10.2166/wst.2008.243 1383 Q IWA Publishing 2008 Water Science & Technology—WST | 57.9 | 2008