Phytoremediation of Diesel Oil Polluted Soil by Fluted Pumpkin (Telfairia Occidentalis Hook F.) in Uyo, Niger Delta Region, Nigeria

Abstract

Phytoremediation is an emerging technology for cleaning contaminated soils. In this study, the effect of fluted pumpkin (Telfaira occidentalis Hook F.) on the degradation of petroleum hydrocarbon in a diesel oil contaminated soil was investigated. Fluted pumpkin seeds were planted in each treatment (0.00, 1.11, 1.59, 2.50 and 3.06%) for a period of 18 weeks. The following parameters were determined: germination percentage, length of vine, number of leaves per vine, leaf yield and the dry weight of leaves and vines on the 3^rd, 6^th, 9^th, 12^th and 15^th weeks after planting (WAP). Total petroleum hydrocarbon (TPH) was determined on the 2^nd and 18^th weeks after oil pollution (WAOP). Total bacterial and fungal counts were determined on the 3^rd, 6^th, 9^th, 12^th, 15^th and 18^th WAOP. The results demonstrated that diesel affected soil depressed seed germination. Length of vine and number of leaves per vine were observed to increase from 3^rd to 15^th WAOP. Leaf yield increased from 3^rd to 9^th WAOP and thereafter declined from 12^th to 15^th WAOP. The results further revealed reduction in dry matter of leaves as concentration of oil increases, whereas dry weight of vines increased with increasing oil pollution. The result also demonstrated that fluted pumpkin stimulated total bacterial and fungal number. Total petroleum hydrocarbon (TPH) removal in the polluted soil was observed to be 86.53, 94.38, 92.80 and 92.97% in 1.11, 1.59, 2.50 and 3.06% concentration respectively. Thus, fluted pumpkin has proved to be efficient for removal of TPH from oil-contaminated soil.

Keywords: Phytoremediation, diesel oil, fluted pumpkin, contaminated soils, petroleum hydrocarbon