Removal of exhausted oils by adsorption on mixed Ca and Mg oxides.
Adsorption tests were performed on two different exhausted oils to reduce their polluting and health hazard potential: a "water-insoluble oil", utilised for automotive engine lubrication, and an "emulsified" oil, used as coolant for metal-cutting tools. Dolomite, a low-cost recovery material, was used to prepare two effective adsorbents: (a) a mixed Ca and Mg oxide obtained by thermal decomposition of dolomite at 1800 degrees C, and (b) an activated material obtained by submitting this product to chemical treatment with HCl. Preliminary tests carried out with an excess of the former material showed that the insoluble oil was adsorbed with lower yield (Y = 0.40) than the soluble (emulsified) oil (Y = 0.60). The material activation with HCl remarkably improved the adsorption of soluble oil organic fraction (Y > 0.90), while only a little increase in the removal yield was observed for the insoluble oil (Y = 0.44). The results presented and discussed in this work pointed out that the products of dolomite calcination can successfully replace the conventional adsorbing materials in the removal of organic pollutants, with particular concern to exhausted soluble oils, which cannot usually be recycled, thus reducing the operational costs of their treatment.
Solisio
Carlo
C
Facolta Ingegneria, Dipartimento di Ingegneria Chimica e di Processo G.B.Bonino, Università di Genova, Genoa, Albaro, Italy. solisio@unige.it
Lodi
Alessandra
A
Converti
Attilio
A
Del
Borghi Marco
BM
D000327:Adsorption; D017610:Calcium Compounds / Q000737:chemistry*; D003247:Conservation of Natural Resources; D004787:Environmental Pollution / Q000517:prevention & control*; D005648:Fuel Oils; D007221:Industry; D008277:Magnesium Oxide / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D012995:Solubility
D017610:Calcium Compounds; D005648:Fuel Oils; D010087:Oxides; D008277:Magnesium Oxide; C016538:lime