Evaluation of Phytoremediation, Physicochemical and Heavy Metal Assessment of Crude Oil Polluted Soil Using Pseudomonas and Bacillus spp, Rivers State, Nigeria

Crude oil exploration has been beneficial to our economy but detrimental to our environment with the artisanal `refineries further compounding the challenge. This research was aimed at investigating the phytoremediation, physicochemical and heavy metal assessment of crude oil polluted soil using Peudomonas spp. and Bacillus spp. as augmenting microorganism, in Rivers state, Nigeria. This study was carried out in in south-south Nigeria (B-dere in Gokana Local government of `Rivers State). Contaminated Soil were collected and subjected to standard microbiological methods. Contaminated Soil samples were collected from two different area of Rivers state with sterilized soil auger at two depths of 0-15cm and 15-30cm. The contaminated soil sampled were analyzed for heavy metal (Cadium Chromium, Lead and Zinc) using Atomic Absorption spectrophotometric method. Microbiological analysis was carried out on the soil samples. Ten (10) treatments consisiting of contaminated soil (CS), uncontaminated soil (US), uncontaminated soil(US), Panicum subalbidum and Schoenoplectus senegalensis were setup for a period of 28 days. Physicochemical parameters were analyzed for uncontaminated soil and contaminated soil. The physicochemical parameters analyzed were pH, Temperature, Nitrogen, Phosphorus, Potassium and Total Hydrocarbon Content. The physiochemical parameters of the uncontaminated soil were pH (5.43), temperature (27oC), Electrical conductivity (9uS/cm), Moisture content (7.80%), Total organic carbon (0.93%), Soil organic matter (1.60%), total Nitrogen (56.695mg/kg), available phosphorus (0.621mg/kg), potassium (7.125mg/kg) and total hydrocarbon content (700mg/kg). Results revealed that the amount of hydrocarbon remediated and percentage (%) bioremediation in the soil after 28 days of monitoring from the initial THC value of (4050 mg/kg), is higher in set up with CS+PSE+SCH (3454mg/kg; 85.28%) and lowest in set up with US+SCH (434mg/kg: 62%) and the amount uptake of phytoremediation in the root after 28 days of monitoring to be higher in set up with CS+BAC+SCH (632Mg/kg; 15.6%) and lowest in set up with US+SCH (12.2mg/kg; 1.74%). The heavy metals assessed were cadium (Cd), chromium (Cr), lead (Pb) and zinc (Zn). This research revealed and recommend that Schoenoplectus senegalensis as a suitable plant species for phytoremediation of crude oil contaminated soil. Hydrocarbon utilizing bacteria identified in this study were; Pseudomonas and Bacilus spp.