Control Technology Research and Environmental Methodologies for the Mitigation of Underground Coal Gasification Impacts: Task 2 Final Report - Control Technology valuation for UGG-Affected Subsurface Waters

摘要

A UCG-affected subsurface water sample was synthesized with altered groundwater and process condensate from the Hanna, Wyoming, UCG site. The concentration of dissolved organic carbon in the water sample closely resembles worst-case contamination of groundwater by soluble organics resulting from UCG. Hot-gas stripping, activated carbon adsorption, coagulation-precipitation, and reverse osmosis were evaluated in a bench-scale treatability study for ability to remove organic and inorganic contaminants from the UCG-affected water. The objective of all treatments was to reduce contaminant concentrations to preburn levels. Ammonia, phenols, calcium hardness, total dissolved solids, sulfate, and selected metals were effectively removed by the process train. The toxicity of the UCG-affected water was reduced substantially by the combination of treatments. Hot-gas stripped, carbon-adsorbed effluent was not lethal to aquatic test organisms at the 100% wastewater concentration.