Treatment of Coal Combustion Residual Liquids for Heavy Metals Using Surface-modified Engineered Iron Media
From the late 1880s until the early 2000’s, coal was used as the primary fuel for electricity generation in the United States. Due to this widespread use, it is no surprise then that coal ash is the second-most abundant waste material in the U.S. As coal-based plants are converted or decommissioned, the need to address soil and groundwater contamination of from coal combustion residuals (CCRs) is a growing concern across the power industry. CCR cleanup can be especially challenging due to the high cost of removing arsenic, lead, molybdenum, and especially selenium, that are present at most sites.
Höganäs Environment Solutions’ (HES) Cleanit®-LC process is an innovative iron-based process for cost-effective removal of selenium and mixed metals from CCR waste streams in a single step. The Cleanit-LC process simultaneous reductive based chemistry couple with physical adoption to remove aqueous phase contamination. The iron based media is manufactured from recycled iron material, hydroelectric power, and can be recycled back into future metal powders in a completely green process.
HES’s engineering team has designed the Cleanit-LC process systems to be both flexible and scalable, ranging from <1 gpm to >5,000 gpm for either fixed of mobile applications. Selenium and other target contaminants can be treated to non-detect levels with empty bed contact times ranging from 3-30 minutes depending on target and water chemistry while requiring reconditioning only every 2-3 weeks. Media life can last from 6 months out to 2 years (or longer) depending on incoming water quality and discharge requirements. Additionally, Cleanit-LC Plus media experiences little to no interference in the presence of competing ions such as sulfates, phosphates, and nitrates.