ABSTRACT
This study was to evaluate the effectiveness of CME in the bioremediation of petroleum hydrocarbon-contaminated soils and its effect on soil pH and exchangeable acidity. Soil samples were treated with CME at different time intervals; CG (general control, neither treated nor polluted), TN (treated once), TM (treated monthly), TW (treated weekly), TD (treated daily), CP (polluted control), PTN (polluted and treated once), PTM (polluted and treated monthly), PTW (polluted and treated weekly) and PTD (polluted and treated daily). Generally, the results revealed a slight variation in pH level of the soil samples. With the CG (general control), TW (treated weekly) and TD (treated daily) having higher pH values of 5.1, 5.1 and 5.5 respectively. While soil samples TN (treated once) and TM (treated monthly) with pH values 4.8 and 4.7 displayed lower pH. Soil sample CP (polluted control) with a pH of 5.4 had a higher pH compared to the CG (general control). The pH of soil samples PTN (polluted and treated once), PTM (polluted and treated monthly), PTW (polluted and treated weekly) also showed a slight increment with a very little difference from the CP (polluted control). Soil sample PTD (polluted daily) displayed the highest pH almost close to neutral with a pH value of 5.8. The general control sample (CG) had a high EA of 4meq/100mg. The treated samples TN (treated once) TM (treated monthly) and TD (treated daily) maintained the same EA concentrations as the CG (general control), with the exception to TW (treated weekly) that showed a decrease in EA level (2meq/100mg). The polluted control (CP) decreased in EA concentration with a value of 2meq/100mg. PTN (polluted and treated once) and PTM (polluted and treated monthly) had higher EA values compared to CP (polluted control) with concentrations 4meq/100mg, 4meq/100mg respectively. Conversely, PTW (polluted and treated weekly) and PTD (polluted and treated daily) showed a decrease in EA levels with concentrations 2meq/100mg, 2meq/100mg respectively. The TPH of the polluted soil samples showed varying concentrations with CP (polluted control) having the highest TPH of 5870.0μg/kg. Meanwhile, the polluted and treated samples (PTN, PTM, PTW, PTD) displayed a decrease in TPH. This study heightened the complex link between CME, petroleum and soil properties, it emphasizes how essential it is to take into account a variety of biological materials when bioremediating petroleum hydrocarbon-contaminated soil, since it offers insightful information about the dynamic interactions between pollutants and soil properties
