Design Concept of a Reverse Osmosis Reject Irrigated Landscape: Connecting Source to Sabkha

Abstract

Feasibility studies in Arizona (U.S.A.) have determined that ocean delivery is a viable disposal option for saline waste water when sourced from near coastline regions. Use of open canals to transport waste water and use of evaporation ponds to reduce waste water volume are standard engineering practices. Engineered designs tend to focus on practicality and efficiency without regard to principles of landscape ecology. The concept of a saline ecosystem with landscape pattern incorporated as the vehicle for an evapotranspiration induced sequence of ecotopes along a directional saline gradient is proposed. This model will serve as a constructive, ecologically-based method to reduce reverse osmosis concentrate waste volume while increasing salinity during transport from source (RO facility) to sink (sabkha). In the process, biota is allowed to self-organize into marsh habitat and the system of pattern creates potential for plant and microbial crops. Potential for research use of the ecosystem is illustrated in light of a conceptual plan for the Santa Clara Slough, located at the northern end of the Sea of Cortez in the Gulf of California.