ABSTRACT
Diesel is a frequently used fuel and a significant water surface pollutant due to leaks and unintentional spills, posing a direct harm to planktons and other aquatic organisms. Using a varying concentrations of WSF of diesel, (0%, 5%, 10%, 25%, 50%, 75%, and 100%), a 14-day study was undertaken in the laboratory to determine the effects of diesel’s water-soluble fractions (WSF) on two test microalgae; Chlorella vulgaris and Scenedesmus obliquus. A 721 UV/Visible spectrophotometer set at a wavelength of 750 nm was used to spectrophotometrically measure the growth response of the two test microalgae (Chlorella vulgaris and Scenedesmus obliquus). The results generally indicated that for Chlorella vulgaris, significant growth was attained at 100% WSF of diesel, for Scenedesmus obliquus the maximum growth was obtained at 75%. The study revealed that both test microalgae, Chlorella vulgaris and Scenedesmus obliquus, had their minimum growth and were greatly inhibited in 10% and 0% WSF of diesel respectively. The concentration of TPH decreased from 12110.79 µg/l in the 100% Diesel WSF to 4173.13µg/l in the Chlorella vulgaris 75% WSF of diesel, and 6053.59µg/l in the Scenedesmus obliquus 75% WSF of diesel at the end of the experiment. Based on the results of total diesel hydrocarbon, the test microalgae were shown to have bioremediation potential. Therefore, these species can be explored as potential candidates in bioremediation of oil-contaminated aquatic environments when the level of contamination is high.ABSTRACT Diesel is a frequently used fuel and a significant water surface pollutant due to leaks and unintentional spills, posing a direct harm to planktons and other aquatic organisms. Using a varying concentrations of WSF of diesel, (0%, 5%, 10%, 25%, 50%, 75%, and 100%), a 14-day study was undertaken in the laboratory to determine the effects of diesel’s water-soluble fractions (WSF) on two test microalgae; Chlorella vulgaris and Scenedesmus obliquus. A 721 UV/Visible spectrophotometer set at a wavelength of 750 nm was used to spectrophotometrically measure the growth response of the two test microalgae (Chlorella vulgaris and Scenedesmus obliquus). The results generally indicated that for Chlorella vulgaris, significant growth was attained at 100% WSF of diesel, for Scenedesmus obliquus the maximum growth was obtained at 75%. The study revealed that both test microalgae, Chlorella vulgaris and Scenedesmus obliquus, had their minimum growth and were greatly inhibited in 10% and 0% WSF of diesel respectively. The concentration of TPH decreased from 12110.79 µg/l in the 100% Diesel WSF to 4173.13µg/l in the Chlorella vulgaris 75% WSF of diesel, and 6053.59µg/l in the Scenedesmus obliquus 75% WSF of diesel at the end of the experiment. Based on the results of total diesel hydrocarbon, the test microalgae were shown to have bioremediation potential. Therefore, these species can be explored as potential candidates in bioremediation of oil-contaminated aquatic environments when the level of contamination is high.
