Cement-based stabilization/solidification of oil refinery sludge: Leaching behavior of alkanes and PAHs

• Published in: Journal of hazardous materials Vol. 148; no. 1; pp. 122 - 135
• Main Authors: Karamalidis, Athanasios K., Voudrias, Evangelos A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 05.09.2007; Elsevier
• Subjects: Alkane quantification; Alkanes; Alkanes - analysis; Alkanes - isolation & purification; Applied sciences; Capsules; Cement; Chemical engineering; Construction Materials; Crystallization, leaching, miscellaneous separations; Exact sciences and technology; Extraction and Processing Industry; General treatment and storage processes; Hazardous Substances - isolation & purification; Industrial Oils; Industrial Waste - prevention & control; Leaching; PAHs; Petroleum; Pollution; Polycyclic Aromatic Hydrocarbons - analysis; Polycyclic Aromatic Hydrocarbons - isolation & purification; Refinery oily sludge; Sewage - chemistry; Solidification; Stabilization; Wastes; Refinery oily sludge; Stabilization; Cement; Alkanes; PAHs; Alkane quantification; Leaching; Solidification; Waste treatment; Immobilization; Hazardous waste; Persistent organic pollutant; Transport process; Alkane; Lixiviation; Organic compounds; Anthracene; Benzopyrene; Hydrocarbon; Refinery; Polycyclic aromatic compound; Binders; Portland cement; Petroleum; Oil industry; Solid waste
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2007.02.032

Stabilization/solidification is a process widely applied for the immobilization of inorganic constituents of hazardous wastes, especially for metals. Cement is usually one of the most common binders for that purpose. However, limited results have been presented on immobilization of hydrocarbons in cement-based stabilized/solidified petroleum solid waste. In this study, real oil refinery sludge samples were stabilized and solidified with various additions of I42.5 and II42.5 cement (Portland and blended cement, respectively) and subject to leaching. The target analytes were total petroleum hydrocarbons, alkanes and 16 polycyclic aromatic hydrocarbons of the EPA priority pollutant list. The experiments showed that the waste was confined in the cement matrix by macroencapsulation. The rapture of the cement structure led to the increase of leachability for most of the hydrocarbons. Leaching of n-alkanes from II42.5 cement-solidified samples was lower than that from I42.5 solidified samples. Leaching of alkanes in the range of n-C 10 to n-C 27 was lower than that of long chain alkanes (> n-C 27), regardless the amount of cement addition. Generally, increasing the cement content in the solidified waste samples, increased individual alkane leachability. This indicated that cement addition resulted in destabilization of the waste. Addition of I42.5 cement favored immobilization of anthracene, benzo[ a]anthracene, benzo[ b]fluoroanthene, benzo[ k]fluoroanthene, benzo[ a]pyrene and dibenzo[ a, h]anthracene. However, addition of II42.5 favored 5 out of 16, i.e., naphthalene, anthracene, benzo[ b]fluoroanthene, benzo[ k]fluoroanthene and dibenzo[ a, h]anthracene.