Wastewater Treatment

Treatment of your wastewater is crucial in meeting your environmental discharge limits and be in compliance.  In addition, Graver’s wastewater systems are focused on treating your wastewater to a quality for recycle and reuse.  This reduces the freshwater required for your process while reducing your overall system operating cost.

OUR EXPERTISE

Graver Water is a key supplier of water and waste water treatment solutions to traditional coal/oil power generation market.  More recently, Graver provides solutions to meet the more stringent EPA regulations related to the new effluent limitation guidelines (ELGs) released on September 2015. The ELGs specify new numerical limits for total dissolved solids, arsenic, mercury, selenium, and nitrate for FGD wastewater.  Using decades of experience in wastewater and FGD treatment in the Power industry, our systems meet the new removal requirements for arsenic, selenium and mercury.

NEW EPA ELGs:  The 2015 ELGs update focuses on six power plant WW streams:

1. Flue gas mercury control (FGMC) system wastewater
2. Bottom ash transport waters
3. Fly ash transport waters
4. Flue gas desulfurization (FGD) wastewater
5. Coal combustion residuals (CCR) leachate
6. IGCC wastewater

Typical Treatment Process

1. FGD purge water is sent to a thickener for solid/liquid separation. Early removal of solids at the first step reduce chemical usage downstream.
2. The stream is sent to a series of chemical reaction tanks where precipitated materials from hydroxide and heavy metals is generated when dissolved contaminants are converted into solid form.
3. The reacted water is then fed to a high rate lamella clarifier for removal of the precipitated solids created from the chemical reaction tanks. Sludge on the lamella outlet is fed to a sludge thickener.
4. Clarified water is then fed to gravity filter for fine particulate removal. Filter backwash is sent to the sludge thickener.
5. Filtered water is fed to the biological system for trace contaminant removal. Biological sludge is generated and fed to the sludge thickener. Treated water is then sent to discharge.
6. Secondary sludge thickener accumulates solids generated and sludge fed to a filter press for dewatering. Thickener liquid effluent is routed back to the FGD wastewater purge tank as a diluting stream and further processing

Contact [email protected] to discuss your plant’s upcoming needs to meet discharge requirements!