Simultaneous grinding and dissolution of TNT solids in an agitated slurry

• Published in: AIChE journal 2001-03, Vol.47 (3), p.572-581
• Main Authors: Gilcrease, Patrick C., Murphy, Vincent G., Reardon, Kenneth F.
• Format: Article
• Language: English
• Subjects: Applied sciences; Biodegradation of pollutants; Biological and medical sciences; Biotechnology; Decontamination. Miscellaneous; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environment and pollution; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Pollution; Pollution, environment geology; Soil and sediments pollution
• ISSN: 0001-1541; 1547-5905
• DOI: 10.1002/aic.690470307

In the slurry‐phase bioremediation of soils contaminated with 2,4,6‐trinitrotoluene (TNT) solids, TNT dissolution can be the rate‐limiting step in the biodegradation process. To determine the effects of slurry concentration on solids dissolution, TNT particles were dissolved in a stirred vessel containing water and inert Teflon (PTFE) chips. For a constant agitator speed, the solid–liquid mass‐transfer coefficient (kL) decreased as the percentage of PTFE solids was increased. However, observed dissolution rates for TNT beads in agitated slurries were much higher than anticipated due to the grinding effect of PTFE chips. A size–mass balance was used to account for the grinding of TNT beads in these slurries; this same balance was then used to predict TNT dissolution rates. Slurry grinding was shown to be an important mechanism for enhancing the dissolution of TNT solids, and the size–mass balance was demonstrated to be an effective tool for modeling this process. These results have important implications for the bioremediation of TNT solids in soil slurry reactors.