Equalization FGD influent Settling tank Hg, As, heavy metals removal Clarification Nutrients and temp. control Se bio-reduction Solid/liquid separation Mixing tank Mixing tank Pre-treatment tank Bioreactor Discharge • A relatively large footprint is required and chemical contamination may occur. • Bacteria are sensitive to temperature and additional nutrients. Phys/Chem and Biological Treatment for Water Discharge UKy-CAER Separation Modules Ultrafiltra'on Nanofiltra'on CDI-1 Holding Vessel CDI-2 Pumps Sensors CDI combined with UF and NF Iron-based Electrocoagulation In-house developed zeolite membrane Continuous operation using CDI, UF, and NF Our Approach Aimed at Water Discharge and Reducing Freshwater Intake FGD influent Flotation with electrocoagulation Nanofiltration Zeolite dewatering Continuous capacitive deionization Solids for landfill Water recycle Solidification Water recycle Other uses Water discharge Water reuse • Develop an intensified process to remove toxic species by electrocoagulation, and reduce TDS/TSS using flotation and membrane-based filtrations. • Practical salt concentration needs for solidification. • Removal of the lower concentration regulated species by CDI. • Process TEA . Project Objective Preliminary Results – Using Electrocoagulation to Reduce Selenate Concentration in Liquid Phase 0 5 10 15 0 10 20 30 40 50 60 Selenate Reduc3on / ppb Thousands Opera3onal Time / min 100 mA 250 mA 500 mA 0 20 min 55 min 11 min Expected Output • More effective solutions to meet ELG for regulated species. • Promote water recycle in power plants. • Aid in understanding of water energy nexus. @500 mA Acknowledgement • DOE/NETL: Barbara Carney and Briggs White • Duke Energy: Neil Kern • LG&E KU Energy: Mahyar Ghorbanian • UKy- CAER, CUMT, SR, and Trimeric. Intensified Flue Gas Desulfurization Water Treatment for Reuse, Solidification, and Discharge (DE-FE0031555) University of Kentucky Center for applied Energy Research FGD Blowdown Limestone slurry recycle FGD scrubber Hydrocyclone Mechanical filtration Slurry makeup Recycle to FGD scrubber Cl - removal for recycle Gypsum production Overflow Water to be treated • The Clean Water Rule requires treatment prior to discharge. • Se VI cannot be effectively removed by phys/chem treatment. Flue Gas in Flue Gas out