Occurrence and Remediation of Polychlorinated Biphenyls in Soil from Jos, Plateau State, Nigeria

Abstract

Investigation into occurrence and Remediation of Polychlorinated biphenyls in soil from Jos, Plateau State Nigeria was carried out. The polychlorinated biphenyls in the soil was extracted with 40ml hexane-acetone mixture (1:1) in ultrasonic bath for 30 minutes and cleaned with column chromatography packed with silica gel. The polychlorinated biphenyls were quantified using Agilent 6975 Gas chromatography Mass Spectrophotometer with the following results: PCB 18 (0.71), PCB 20 (0.37), PCB 28 (0.38), PCB 29 (0.38), PCB 44 (0.42), PCB 52 (0.66), PCB 101 (0.61), PCB 105 (0.17), PCB 137 (0.64), PCB 142 (0.33), PCB 153 (0.42), PCB 170 (0.13) and PCB 180 (0.21) all in mg/kg. Remediation with Moringa seed results in the followings; PCB 20 (0.28), PCB 28 (0.28), PCB 29 (0.28), PCB 52 (0.30), PCB 101 (0.18), PCB 143 (0.91) while the other congeners were completely removed. The Moringa seed powder results completely removed the PCBs sake PCB 44. The effectiveness of the powder as compared with the seed in the removal of the PCBs might be attributed to the increased surface area of the seed powder providing for better interaction with the contaminated soil. Whereas the results from the use of activated carbon only removed PCB 105 completely and reduced the concentrations of other congeners as follows: PCB 18 (0.04), PCB 20 (0.011), PCB 28 (0.019), PCB 29 (0.019), PCB 44 (0.021), PCB 52 (0.33), PCB 101 (0.031), PCB137 (0.032), PCB 142 (0.017), PCB 153 (0.021), PCB 170 (0.007) and PCB 180 (0.011) all in mg/kg. The result suggests that Moringa seed powder could possibly serve as an excellent means of remediation for Polychlorinated biphenyls in contaminated soil.