Abattoir waste water attenuates kerosene toxicity on cowpea (Vigna unguiculuta) seedlings

Abstract

Nigeria is a major producer of crude oil resulting in spillages that contaminate both cultivated and uncultivated farmlands. This exposes the immediate biota to the deleterious effect of petroleum hydrocarbons. The aim of the present investigation is to determine the ability of cowpea seedlings to handle exposure to kerosene in the presence of abattoir waste water. Poly bags were filled sieved soil and divided into six groups of five replicates. Groups 1 to 5 contained 0.1%, 0.25%, 0.5%, 1.0% and 2.0% (v/w) kerosene while group six served as control (0.0%) Corresponding concentrations were prepared and then treated with known amount of abattoir waste water. Cowpea seedlings were planted in each bag and the activity of suphite oxidase determined in the leaves twelve days after planting. The result indicates that kerosene treatment of soil caused a progressive decrease in sulphite oxidase activity as the concentration of kerosene in soil increases. The decrease in sulphite oxidase activity was significant (p<0.05) at 0.5% - 2% kerosene treatment of soil. Moreover, treatment of soil with abattoir waste water caused a significant (P<0.05) increase in the enzyme activity relative to the corresponding kerosene in soil treatment. However, at higher concentration of kerosene in soil, the activity of the enzyme was still significantly (P<0.05) lower relative to the control. This is against the near restoration of the enzyme activity at low concentration of kerosene in soil. These observations indicate abattoir waste can remediate the toxic effect of kerosene at low levels of soil contamination.