Investigation of Characteristics of Vernonia amygdalina Stem on Remediation of Crude Oil Polluted Loamy Soil Environment

Abstract

The effectiveness of Vernonia amygdalina in Total Petroleum Hydrocarbon (TPH) mitigation in a loamy soil environment was monitored using mixture of 100ml of Crude oil, 2kg of loamy soil and 25g to 100g of remediant determined. The experiment was set-up based on the design concept considered as presented in this research, which involved constant volume of 100ml of crude oil, constant mass of 2kg of loamy and changes in mass of remediant added in bioreactors from 25g to 100g with incremental step of 25g and each bioreactor was sampled at time period of 7 days for a period of 42 days. The effect on the changes on the physicochemical parameters at 42 days only. The percentage removal or reduction in terms of Total Petroleum Hydrocarbon (TPH) was evaluated as remediation continuous until 42 days where 57.89% was obtained at maximum for application of sun-dried sample of Vernonia amygdalina and 85.94% was obtained at maximum for room dried sample. The parameters were monitored which include values of the initial (42 days) and the following results were achieved. For zero day total dissolved solid (TDS) 141.46 mg/c, electrical conductivity 375.0 μS/cm, temperature 26.20°C, pH 6.30, chloride 3663.4mg/l, sulphate 72.13mg/l, nitrate 4.27mg/l, turbidity 3.86 NTU, alkalinity 148.3, oil and Greece 18.16mg/l, dissolved oxygen 15.82mg/l, iron 0.60 and 193.85mg/l. The physicochemical properties of the biostimulant for sun and room dried prepared were electrical conductivity 163.3 μS/cm , pH 5.95, temperature 25.9°C, total nitrogen 0.68% and potassium 126.11mg/l for sun dried whereas for room electrical conductivity 182.7 μS/cm, pH 6.04, temperature 27.1°C, total organic carbon 9.2%, total phosphorous 30.74%, total nitrogen 0.68% and potassium 158.4mg/kg. The research further showcases reduction in some of the physicochemical parameters as well as increase in pH value. These changes has demonstrated increase in rapid restoration of the loamy soil characteristics in terms of physiochemical parameters of the soil for agricultural utilization.