The case study Heartland Water Technology’s LM-HT Concentrator Provides ZLD Treatment of FGD Purge Water Using Flue Gas as Thermal Energy Source details a demonstration project by Heartland Water Technology in partnership with The Electric Power Research Institute (EPRI). The project evaluated the Heartland LM-HT® Concentrator's capability to treat Flue Gas Desulfurization (FGD) purge water to Zero Liquid Discharge (ZLD) using flue gas as the thermal energy source.
Over the course of 14 days, the concentrator treated over 10,000 gallons of FGD wastewater, achieving a net volume reduction of 90-95% and turning 3.5% solids into 40% solids content. This process involved using flue gas to evaporate water, with the evaporated water reintroduced into the system, thereby not affecting air emissions. The residual slurry was further processed to reach 80% solids content.
The system demonstrated flexibility and robustness, maintaining operation across varying conditions with minimal downtime. The treated residues met environmental standards for non-hazardous disposal. The project highlighted the potential of using waste heat for efficient and compliant wastewater treatment in power plants.