Ameliorative effect of sodium carbonate on phytotoxicity of palm oil mill effluent

Abstract

This study aims to evaluate the impact of palm oil mill effluent treated with sodium carbonate on the growth of maize. The experiment consisted of eight treatments of concentrations of palm oil mill effluent viz 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 6.0%, 7.0% and 8.0%. The treatment was carried out on potted maize plants with six replications. Four kilograms of soil was weighed into each pot. Six pots were labelled as control with untreated palm oil mill effluent added to them. Eight other groups consisting of six pots each were treated with 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 6.0%, 7.0% and 8.0% concentrations of the effluent. The maize seeds were planted one in each pot to avoid overcrowding. The pots were transferred to greenhouse and moistened daily with the effluent. The growth rate, plant height and leaf length of the maize plants were thereafter determined. The 8.0% concentration of sodium carbonate in the effluent had the highest expected effect on the parameters whereas the control gave the lowest expected effect. The effects increased as the concentration of sodium carbonate in the effluent increased, indicating that increased concentration of sodium carbonate recorded significant increase in growth rate, height and leaf length of maize. The analysis of variance for the obtained data showed that the effects of the different concentrations were significantly different. This study provides an alternative and cost effective method of ameliorating the toxicity of palm oil mill effluent to plants.