బయోరేమిడియేషన్ & బయోడిగ్రేడేషన్ జర్నల్

నైరూప్య

Post-Remediation Assessment of Crude Oil Polluted Site at Kegbara-Dere Community, Gokana L.G.A. of Rivers State, Nigeria

Tanee FBG and E Albert

Post-remediation assessments of crude oil polluted sites at Kegbara-Dere community in Gokana Local Government Area of Rivers State, Nigeria were carried out to ascertain the degree of success of remediation work done by SPDC in the area in 2008. Soil samples were collected from 3 sites within the location viz; crude oil polluted unremediated site (A), crude oil polluted remediated site (B) and a control site of no pollution and remediation (C). Soil samples were collected at 3 soil depth levels of 0-5cm, 10-15cm and 20-25cm using soil auger and analysed for soil , conductivity, phosphate, nitrate, total organic carbon (TOC), total hydrocarbon content(THC) and total exchangeable cations (TEC). Soil pH and conductivity were obtained with a pH meter (Hanna Hi 8314) and conductivity meter (HACH Ecttesr microprocessor series) respectively. Total hydrocarbon content was measured by spectrophotometric method; total organic carbon content by oxidation method; nitrate content by Kjeldahl method, Phosphate content by ascorbic acid method and total exchangeable cations (Na + , K + , Mg 2+ and Ca 2+ ) by Atomic Absorption Spectrophometer method (AAS). Result showed no significant difference in the soil pH between and within sites. Soil conductivity, nitrate and phosphate improved significantly in the remediated site than the unremediated site. There was a drastic reduction in the total hydrocarbon content (THC) in the remediated site with the highest value of 100 mg/kg as against 350 mg/kg in the unremediated site. Total organic carbon (TOC) fluctuated between and within the 3 sites in the range of 3.63 - 4.11%. Ca 2+ was undetected in the remediated site especially at the 20- 25cm soil depth. This is an indication that the remediation carried out was successful.