Next Generation Brine Desalination and Management for Efficiency, Reliability, and Sustainability

uwait’s coast is located in one of the shallowest and most saline sections of the Arabian Gulf (up to 49,000ppm), which brings about many challenges in the seawater desalination. Discharges from Kuwait’s desalination plants return high salinity brines to the Gulf, and may contain other contaminants such as chlorine or chromium, resulting in environmental impacts to the coastal region. Conversely, treated wastewater discharges to the Gulf have low salinity, but continuous discharge may pose a potential threat to the marine environment by increasing the amount of pollutants in the coastal waters and may drive eutrophication. In this project, we will aim to increase both energetic and environmental sustainability of Kuwaiti water management by developing / validating novel ideas and interfacing them optimally with existing plant workflow.

Three major themes of the project are:

(1) Electrical desalination for brine management: We will capitalize on unique advantages of electrical desalination for pre- and post-treatment of source water to enhance the efficiency of the existing desalination plant. This will serve as our primary application. Proof-of-concept systems will be tested both at MIT and Kuwait, coupled with a detailed techno-economic analysis toward optimized integration. We will use the strategy of multi-stage optimization, which achieves energy efficiency by minimizing irreversibility in the overall process through local management of concentration differentials. We will also employ a model-based engineering to both microscopic-process and system-wide optimization, by taking advantage of advances in modeling multi-scale phenomena near ion selective membranes, as well as a more comprehensive understanding of irreversibility in the electrical desalination process.

(2) Power generation using brine and wastewater: Pressure retarded osmosis (PRO) and reverse electrodialysis (RED) are emerging, membrane-based technologies for recovering energy from concentration differences between water streams. We will examine the potential of using PRO and/or RED to recover energy from Kuwait’s desalination and wastewater plants while simultaneously reducing the salinity of the discharged brine by membrane-regulated dilution with wastewater and/or seawater. Coastal discharge configurations will be designed, and methods to fully mitigate the environmental impact of the discharged streams will be evaluated. This study will result in clear assessment of the potential of combining brine and wastewater discharge to lessen environmental impacts on the Kuwaiti coast while reducing the overall cost of water treatment through the recovery of renewable energy with reduced carbon emission via PRO or RED.

(3) Engineering for Increased Reliability: We will also address the significant challenge of bio-fouling, scale formation, and particulate removal, by employing recent innovations in surface coating and microfluidic separation processes. Antifouling membrane coatings appropriate to the combined streams will be developed.