1 research outputs found
Chemical Characterization of High-Temperature Arc Gasification Slag with a Focus on Element Release in the Environment
High-temperature
arc gasification (HTAG) has been proposed as a
viable technology for the generation of energy and the production
of saleable byproducts from municipal solid waste (MSW). Total concentrations
of elements in HTAG slag were assessed and indicated a high partitioning
of trace elements (Pb, Cd, and As) into the flue gas, an issue of
concern when assessing the air pollution control residues (APCR) status
as a hazardous waste. Hazardous waste leaching tests [such as the
toxicity characteristic leaching procedure (TCLP)] were performed
and confirmed that the slag did not meet U.S. criteria for a hazardous
waste. Leaching was assessed using batch and column tests; the results
revealed that Sb and Al were elevated in respect to risk-based regulatory
thresholds. Slag samples were carbonated to simulate weathering effects,
and although leachable concentrations of Al did decrease by an order
of magnitude, Sb concentrations were found to increase. Low total
concentrations of certain trace elements (As, Cd, and Pb), with respect
to MSW incineration bottom ashes support the potential for reuse of
HTAG slag; however, leaching of elements (Pb, Al, and Sb) in batch
and column tests indicate that proper engineering controls would need
to be taken to ensure protection of water supplies in a reuse application