SPENT ENGINE OIL

Contamination of soils due to spent engine oil is an important environmental issue affecting soil characteristics and plant growth. This study was aimed at evaluating the effects of spent engine oil on growth parameters of Saccharum spontaneum L. for potential use in phytoremediation of oil polluted environments. Spent engine oil from a motor service garage was prepared in five concentrations of 4, 8, 16, 32 and 64ml/Kg. Tillers of S. spontaneum were planted in top garden soil and allowed to stabilize for four weeks before treatments were added. A control experiment in four replicates was also set up. The control had a significantly higher number of tillers compared to the different concentration treatment groups. The higher concentrations of 16, 32 and 64ml/Kg of spent engine oil contaminated soil did not produce any tillers at all. Total aliphatic hydrocarbon content was lowest in the control and highest in the 64ml/Kg treatment. Total polynuclear aromatic hydrocarbon was highest in the 32ml/Kg treatment. Soil chemical parameters did not show a dose dependent response to increase in treatment with spent engine oil. This report demonstrated that lower concentrations of spent engine oil enhanced the number of leaves, plant height and leaf area of S. spontaneum. Results showed that S. spontaneum was tolerant to, and thrived at low concentrations of contamination with spent engine oil but declined in growth and development at high concentrations and for extended periods

A screen house potted experience was conducted in the Department of Crop Science, Faculty of Agriculture, University of Benin, Benin City in June to August, 2023 to evaluate the effects of different level of spent engine oil (SEO) contamination remediated with spent mushroom substrate (SMS) on the growth and herbage yield of Amaranth (Amaranth hybridus). The experiment involved three spent engine oil contamination levels (0, 5 and 10% v/w per 10kg soil) and four spent mushroom substrate application rates (0, 200, 400 and 600 per 10kg soil) laid in a 3 x 4 factorial arrangement fitted into a completely randomized design (CRD) and replicated three times. Data were collected on plant height, stem girth, number of leaves, leaf area and herbage yield. The results of soil analysis before cropping with Amaranth showed that SEO had no effect on particle size of the soil. Organic C, H+ and Al3+ in the contaminated soils were higher compared to the control. There was decreased in concentrations of available P, total N, exchangeable cations as the SEO contamination level increased. Plant height, stem girth, number of leaves, leaf area and herbage yield of Amaranth plants grown in the contaminated soils were adversely affected as they were significant (P<0.05) reduced in comparison to their performance in unpolluted soils. Application of SMS enhanced growth and herbage yield of Amaranth. Application of SMS remediated the harmful effect of SEO on the plant as it enhanced the growth of the plant. However, higher rate of SMS application reduced growth and 10 herbage yield of Amaranth in comparison to the lower rate. Application of 200g of SMS per 10kg soil produced plants with the highest height (89.2cm), thickest stem(3.42cm), highest number of leaves (28.6cm), largest leaf area (2803cm²) and herbageyield (59.91tha-¹). A combination of unpolluted soil treated with 200g and 400g ofSMS produced the highest herbage yield with 72.9 and 75.1g, respectively. SMS at200g is thereby suggested for Amaranth growers