Physico-chemical remediation of polycyclic aromatic hydrocarbons contaminated soil

Abstract

This study exploited the solvent extraction and mechanical agitation techniques for the remediation of soils contaminated with polycyclic aromatic hydrocarbons (PAHs). The removal of pollutants from diesel contaminated site through ethanol, hexane, and ethanol-hexane mixtures was evaluated. 50 g dried contaminated soil was placed in a Soxhlet extractor and 250 ml solvent (ethanol, or hexane, or ethanol-hexane mixture) was added with extraction occurring at different temperatures of 30, 35, 45, 50, and 60 °C for 16 h. Mechanically agitated method was carried out by weighing out an equal amount of 50 g of the contaminated soil, thoroughly washing with 250 ml of ethanol, hexane, and equal ratio of ethanol to hexane. Qualitative analysis recovered PAHs was done by Agilent series gas chromatography equipped with flame ionization detector. The chromatographic evaluations of the solvent extraction of the contaminated soil showed that more of the polluted compounds were removed when hexane was the solvent. The maximum yield of extracted diesel by the solvent hexane was 11.84% at 60 °C. Extracted diesel removal was also directly proportional to periods of extraction.

Contamination Assessment of Underground Water Around a Cemetery: Case study of Ayobo cemetery in Lagos, Nigeria

“…Seepages from the cemeteries result from the decaying bodies [44], burial materials and other matters [45,46]. Planting of trees and border plants around the vicinity of cemeteries, have been prescribed to help curb and/or control the transport of microorganisms (viruses and bacteria) in water and rain water seepage (44).…”

Biorecovery of Agricultural Soil Impacted by Waste Motor Oil with Phaseolus vulgaris and Xanthobacter autotrophicus

“…Measurement of the decrease in the WMO hydrocarbon concentration in the soil after biostimulation and bioaugmentation was performed as a total petroleum hydrocarbon decrease analysis using the Soxhlet extraction method. Soxhlet extraction is a classical method for the extraction of thermally stable and recalcitrant organic compounds from complex matrices [ 38 , 39 , 40 ].…”

“…Germination percentage was measured at six days, and phenology and biomass were measured at the seedling and physiological maturity stages as indicators. After two months of phytoremediation, the final concentration of WMO was determined by total petroleum hydrocarbon decrease analysis using the Soxhlet extraction method [ 27 , 38 , 39 , 40 ]. Finally, soil samples with WMO were analyzed using an Agilent Technologies 7890A series gas chromatograph coupled to 5975C inert mass spectrometer (Conquer Scientific, Poway, CA, USA); 1.0 µL of the sample was injected in splitless mode, helium (99.995% purity) was used as the carrier gas in a Zebron-5MS capillary column with 30.0 m length, 0.25 mm internal diameter, and 0.25 mm film thickness.…”