Inland desalination projects tapping brackish or saline groundwater face challenges and expense to manage concentrate generated by desalination processes. This study presents an innovative approach to provide beneficial reuse for desalination concentrate. A preliminary feasibility study is underway to evaluate a groundwater desalination project that uses concentrate as the water source for a landfill bioreactor renewable energy system. The approach co-locates a desalination water treatment facility with a landfill bioreactor gas-to-energy system in a cogeneration process that provides improved efficiencies for both the desalination system and the landfill bioreactor. Desalination has high energy requirements that can be met by landfill bioreactor renewable energy production, and the landfill bioreactor requires water addition that can be met by the desalination concentrate stream. The cogeneration project combines the two emerging technologies in a unique and complementary way to produce a variety of environmental and economic benefits. The desalination/landfill bioreactor cogeneration system must balance multiple components of the project to maximize desalination supplies and energy production capacity. Preliminary feasibility study results indicate: (1) desalination production capacity of several million gallons per day may be expected when balancing concentrate addition with the solid waste-stream in mid- to large-size landfills, (2) desalination concentrate and landfill leachate are similar in salt concentration so methane producing bacteria can thrive, and (3) landfill bioreactors have gained regulatory acceptance and are used increasingly to generate renewable energy, improve waste disposal efficiency, and capitalize on financial incentives. Considerable interest exists among desalination professionals to identify beneficial concentrate reuse options. Reuse of concentrate as the water source for landfill bioreactor operation is a promising approach to provide dual benefits and lower costs for each component of the desalination/landfill bioreactor cogeneration system.
展开▼
