The Positive Significance of Cymbopogon citratus (Lemon Grass) in Remediation of Crude Oil in the Environment of Soil

Abstract

The effectiveness of using lemon grass in the remediation of soil contaminated by crude oil was investigated. The material investigated is lemon grass and the potential in terms of performance was monitored with biokinetic parameters evaluation. Six samples of 1000g of soil each were polluted with 100 ml of raw crude oil.  The samples were later amended with dosage of 20g, 40g, 60g, 80g and 100g of dried lemon grass granules. W6 is left without amendment which stand as control for the experiment. The set up was then left for a period of 42days while the physiochemical analysis was carried out on soil, lemon grass and crude oil separately before mixing. The determined physiochemical parameters were Total Petroleum Hydrocarbon (TPH), pH, Total nitrogen, Total organic carbon, Potassium, Phosphorous and hydrocarbon degrading bacteria, the results show that the soils were sandy loam. First order bioremediation kinetics and lemon grass efficiency for these samples were studied by monitoring the TPH of six replicate samples, and the result shows that with time it decreased from 117060ppm to 20537ppm, 15320ppm, 12223ppm, 6979ppm, 3355ppm and 33777ppm respectively. Percentage of TPH removed was calculated to be 23.96% for 20g, 37.20% for 40g, 40.88% for 60g, 57.66% for 80g ,71.98% for 100g of lemon grass amendment and 8.49% without amendment for six samples after 42days of remediation. The result obtained at the end of the bioremediation period, revealed that an increase in the concentration of lemon grass in amended crude oil polluted soil increases the rate of TPH removal with time, faster and better than without lemon grass plus raw crude oil polluted soil (Control). Therefore, it is recommended that lemon grass is effective to an extent for bioremediation to any area undergoing pollution like Niger delta State of Nigeria.