Thermal desorption of polychlorobiphenyls from contaminated soils and their hydrodechlorination using Pd- and Rh-supported catalysts

• Published in: Chemosphere (Oxford) Vol. 70; no. 6; pp. 1052 - 1058
• Main Authors: Aresta, M., Dibenedetto, A., Fragale, C., Giannoccaro, P., Pastore, C., Zammiello, D., Ferragina, C.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 2008; Elsevier
• Subjects: Adsorption; Applied sciences; Catalysis; catalysts; chemical reactions; Contaminated soils; dechlorination; Decontamination. Miscellaneous; desorption; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Restoration and Remediation - methods; Exact sciences and technology; heat treatment; Hydrodechlorination; Models, Theoretical; palladium; Palladium - chemistry; Pd- and Rh-supported catalysts; Pollution; Pollution, environment geology; polychlorinated biphenyls; Polychlorinated Biphenyls - chemistry; Polychlorobiphenyls; remediation; rhodium; Rhodium - chemistry; Soil and sediments pollution; soil heating; Soil Pollutants - chemistry; soil pollution; Temperature; Polychlorobiphenyls; Contaminated soils; Pd- and Rh-supported catalysts; Hydrodechlorination; Catalytic reaction; Thermodesorption; Palladium; Soil pollution; Organic chlorine compounds; Hydrogenation; Zirconium Phosphates; Supported catalyst; Persistent organic pollutant; Dechlorination; Decontamination; Rhodium; Chlorocarbon; Aromatic compound; Organic compounds
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2007.07.074

This paper reports about a combined technology for soil remediation from PCBs using the thermal desorption technique coupled with the catalytic hydrogenation of recovered PCBs. The reactor is a bench scale rotating desorption furnace through which nitrogen is flushed and used as carrier gas of desorbed PCBs. The latter are condensed into an hexane or hexane–acetone (1:1 v/v) solution that is then hydrogenated using phosphate-supported Pd or Rh as catalyst. The analysis of the treated soil, under variable operative conditions (temperature and desorption time), shows that the total (99.8%) decontamination from PCBs occurs. The recovery yield of the desorbed PCBs is better than 75% and the subsequent hydrogenation reaches 63% of the collected PCBs in 5 h or 100% in 12 h.