General Electric has introduced an evaporation/solidification system for flue gas desulfurization (FGD) that is designed meet new EPA guidelines for wastewater discharge from steam electric and coal-fired power plants.
The new EPA effluent limitations guidelines (ELGs) will reduce or eliminate toxic metals and other pollutants from entering surface waters from steam electric power plants. The new rules specifically address FGD wastewater from coal-fired power plants and identify chemical precipitation followed by biological treatment as the best available technology for treating and discharging the waste from existing plants and evaporation/solidification for new facilities. The ELGs also identify the evaporation/solidification approach as a best available technology for eliminating FGD waste streams from existing power plants under a voluntary incentive program.
GE’s new evaporation/solidification system reduces chemical addition, sludge handling and energy costs. It reduces the long-term environmental risks associated with the discharge of FGD purge water and other liquid streams from power plants. The system produces high-quality water for recycle and reuse.
Compared to traditional zero liquid discharge (ZLD) systems, GE says its new system offers significant reductions in capital and operating expenses. The system can treat FGD wastewater from any type of coal and removes the risk of meeting stringent discharge requirements by eliminating liquid discharge to waterways. It also significantly reduces the risks to operators associated with the management of solid landfill waste.
The new EPA ELGs apply directly to FGD purge stream treatment and do not allow internal dilution. Power plants can either treat and discharge their waste streams or eliminate it with an evaporation system. Each power plant must comply between 2018 and 2023, depending on when a new Clean Water Act permit is needed.