ENVIRONMENTAL SOIL PHYTOREMEDIATION USING MANGROVE PARTS FOR CRUDE OIL AND HEAVY METAL REMEDIATION IN SELECTED SITES IN RIVERS STATE, NIGERIA

The study investigates the use of mangrove parts (branch, leaves, stem and root) as a tool for crude oil remediation in selected sites in Rivers State, Nigeria. The study tends to determine the physicochemistry of soils phytoremediated with different plant parts and to determine the THC increase or decrease in each of these soils over time in order to determine the plant parts with highest remediation power based on soil THC and microbial load. Random sampling was used in obtaining soil samples at the Jetty Mangrove site. The different sampling points were homogenized to form a true representative of the mangrove soil. The Mangrove parts were oven dried to constant weight for 72 hours at 60oC before being homogenized with plastic mortar and pestle prior to the experiment. EPA Method 418 was used to determine the Total Hydrocarbon Content (THC). Heavy metals such as Cadmium, Lead and Zinc were determined using AAS- Atomic Absorption Spectrometry method while the microbial load was estimated using the plate viable count method. Results showed that all the mangrove plant parts phytoremediated the soils in the order root > leaf > branch > stem with values 21.5, 18.6 and 26.3 for root, 16.0, 11.9 and 143.9 for stem, 94.2, 80.6 and 15.8 for leaf and 28, 34.8 and 217.8 for branch respectively. The research which was observed for six months at two months intervals showed progressive decrease in THC and the Heavy metal composition and an increase in the microbial load. Hence, mangrove parts especially the roots are potential tools for bioremediation of polluted soils and if explored can serve as a cheap, available and effective source of materials for phytoremediation