TY - JOUR

T1 - Effects of thermal treatment on mineralogy and heavy metal behavior in iron oxide stabilized air pollution control residues

AU - Koch, Christian Bender

AU - Stackpoole, Mairead M.

AU - Bordia, Rajendra K.

AU - Benjamin, Mark M.

PY - 2000/11/1

Y1 - 2000/11/1

N2 - Stabilization of air pollution control residues by coprecipitation with ferrous iron and subsequent thermal treatment (at 600 and 900 °C) has been examined as a means to reduce heavy metal leaching and to improve product stability. Changes in mineralogy and metal binding were analyzed using various analytical and environmental techniques. Ferrihydrite was formed initially but transformed upon thermal treatment to more stable and crystalline iron oxides (maghemite and hematite). For some metals leaching studies showed more substantial binding after thermal treatment, while other metals either volatilized or destabilized with respect to leaching. Pb, in particular, exhibited increased reactivity following the formation of an ordered iron oxide structure at 900 °C. The thermal treatment had a positive effect on Cr release, which was reduced significantly at 900 °C in the presence of organic matter. Thermal treatment of the stabilized residues produced structures with an inherently better iron oxide stability. However, the concentration of metals in the leachate generally increased as a consequence of the decreased solubility of metals in the more stable iron oxide structure.

AB - Stabilization of air pollution control residues by coprecipitation with ferrous iron and subsequent thermal treatment (at 600 and 900 °C) has been examined as a means to reduce heavy metal leaching and to improve product stability. Changes in mineralogy and metal binding were analyzed using various analytical and environmental techniques. Ferrihydrite was formed initially but transformed upon thermal treatment to more stable and crystalline iron oxides (maghemite and hematite). For some metals leaching studies showed more substantial binding after thermal treatment, while other metals either volatilized or destabilized with respect to leaching. Pb, in particular, exhibited increased reactivity following the formation of an ordered iron oxide structure at 900 °C. The thermal treatment had a positive effect on Cr release, which was reduced significantly at 900 °C in the presence of organic matter. Thermal treatment of the stabilized residues produced structures with an inherently better iron oxide stability. However, the concentration of metals in the leachate generally increased as a consequence of the decreased solubility of metals in the more stable iron oxide structure.

UR - http://www.scopus.com/inward/record.url?scp=0034332536&partnerID=8YFLogxK

U2 - 10.1021/es0009830

DO - 10.1021/es0009830

M3 - Journal article

AN - SCOPUS:0034332536

VL - 34

SP - 4620

EP - 4627

JO - Environmental Science & Technology

JF - Environmental Science & Technology

SN - 0013-936X

IS - 21

ER -