Abstract

Bioremediation of Crude Oil Contaminated Soil Using Organic and Inorganic Fertilizers

Rowland U Ofoegbu, Yusuf O L Momoh and Ify L Nwaogazie

The study involves the use of first-order kinetics model in the remediation of crude oil contaminated arable soil at 2, 4, and 6% crude oil spill respectively, this was biostimulated with inorganic fertilizer (NPK), cow dung (CD), and palm kernel husk ash (PKHA) applied singly and in combinations (cow dung & inorganic fertilizer); (cow dung & palm kernel husk ash) in a 50:50 ratio. The experiment was a randomized complete block design (RCBD), which was conducted in two phases, i.e., the first block comprises of inorganic fertilizer and cow dung, while the second block consist of cow dung and palm kernel husk ash used singly and in combination. The degree of biodegradation was observed for a remediation period of 40 days under laboratory conditions. The results obtained reveal a positive correlation coefficient for the various biostimulants used. Also, student’s t-test conducted reveals a significant p<0.05, in remediation for the various biostimulants, when compared with the unamended soil. This research study shows that a higher biodegradation rate constant (k) and a low half life time ( ⁄ ) exist for amendments with (cow dung & inorganic fertilizer) and gradually varies with other biostimulants. From the estimated biostimulation efficiency (B.E) and biodegradation rate constant (k), the orders of remediation from the most treated are: A combination (inorganic fertilizer & cow dung)> inorganic fertilizer used singly> cow dung used singly> combination (cow dung & palm kernel husk ash)> and finally palm kernel husk ash used singly at 2, 4% crude oil contamination, and inorganic fertilizer preceding before a combination (inorganic fertilizer & cow dung) at 6% crude oil contamination.