Effect of storage on the toxic potential of hydrocarbon containing sludges

✍ Scribed by I. S. Morelli; G. I. Vecchioli; O. R. Costanza; R. Schäfer; L. Berthe-Corti; M. T. Painceira

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 121 KB
• Volume: 14
• Category: Article
• ISSN: 1520-4081
• DOI: 10.1002/(sici)1522-7278(199905)14:2<227::aid-tox3>3.0.co;2-h

✦ Synopsis

In many cases, petroleum-derived sludges are stored in open air ponds. In this condition, weathering may produce changes that can be important when choosing a treatment and / or disposal method. The effect of weathering on chemical and toxicological characteristics of sludges were studied ( ) in two different sludges, one from a petrochemical API-separator API2N and the other from a refinery biological treatment unit. Starting determinations were performed with end-of-the-pipe composite samples. Determinations were repeated after a 6-month weathering period. Physico-chemical characterization included pH, water content, extractable organics, and class fractionation into aliphatics, aromatics, and asphaltics. Microbiological concentration was done by enumeration of viable bacteria in plate count agar and solid mineral medium with the sludge as the only source of carbon and energy, and fungi in Cooke rose bengal agar. For toxicological assessment a battery of bioassays was performed that included: Bacillus cereus spot test, Resazurine reduction test, Bioluminiscence test with Photobacterium, effects on viable soil bacteria counts, Latuca sativa seed germination and root elongation test.

( ) The Ames test TA-98 with S9 microsomal activation was used to assess genotoxicity changes. Comparison of starting results of both sludges with those obtained after 6 months showed a minimal change in the chemical characteristics, a significant increase in the starting low level of bacteria in API2N, reduction in acute toxicity and increase in the mutagenic effect in the dimethyl sulfoxide ( ) DMSO -sludges fraction, but not in the DMSO-ethylether organic fraction in both sludges. ᮊ 1999 by