Tests of stability on waste produced in pilot plant testing using ferrous(center dot)EDTA and magnesium-enhanced lime for combined SO(sub 2)/NO(sub x) removal

摘要

A pilot-plant-scale study of combined sulfur dioxide/nitrogen oxides (SO(sub 2)/NO(sub x)) removal has been performed by the Dravo Lime Company at the Cincinnati Gas and Electric Company's Miami Fort Station in North Bend, Ohio. This study used Dravo's patented Thiosorbic(reg sign) lime process, utilizing a magnesium-enhanced lime, along with Argonne National Laboratory's (ANL's) patented ARGONOX metal-chelate additive, ferrous(center dot)ethylenediaminetetraacetic acid (Fe(center dot)EDTA). For approximately nine months, scrubbing tests were carried out, and waste samples were collected. Waste testing at ANL involved two types of long-term chemical stability experiments. In one experiment, the gas-phase composition above several different samples was studied by mass spectrometry over a period of about 22 months. Significant changes were noted for oxygen (O(sub 2)), carbon dioxide (CO(sub 2)), and hydrogen sulfide (H(sub 2)S) gases. The other experiment involved solid-phase leaching using the Toxicity Characteristic Leaching Procedure (TCLP). Samples were stored for up to 14 months before leaching. Then each leachate was tested for total Kjeldahl nitrogen and for some nitrogen-containing species. Total leachable nitrogen was found to stabilize after about the first seven months of storage.