Journal of Applied Biosciences (J. Appl. Biosci.) [ISSN 1997 - 5902]
Volume 30: 1866 - 1872. Published June 9, 2010.
Comparative assessment of the effect of produced water (PW) and water soluble fraction (WSF) of crude oil on the growth and catalase activity of Allium cepa L
Edema, E. Noyo
Department of Botany, Delta State University, PMB1 Abraka, Nigeria
Corresponding author email: drangeledema@yahoo.comABSTRACT
Objective: To comparatively assess the effect of produced water (PW) and the water soluble fraction (WSF) of Ughelli east crude oil on the growth and catalase activity of Allium cepa.
Methodology and results: The levels of treatments used were 0 for control (deionized water), 25, 50 and 100% (PW and WSF) of crude oil, each having three replicates. The plants were exposed to the treatments for 12 days. The results showed a reduction in root lengths and the number of roots of A. cepa with increase in concentrations of the two treatments, except at 50% WSF treatment, where the result had significantly (P<0.005) lower values for root length (2.96cm ±0.47) as compared to 100% WSF (3.69cm± 6.71). At the same level of treatment of 50% WSF there was significant (P<0.005) increase in the number of roots when compared with 25% WSF treatment. Initiation of growth at 50 and 100% WSF were recorded on the first and second days of exposure. Leaf bud formation was observed only at 25% WSF treatment level. Increase in catalase activity was observed with increase in percent WSF. Catalase activity could not be measured for PW because there was inhibition (zero growth) at 100% treatment. While 25 and 50% (PW) the fresh weights produced from the three replicates were not sufficient for the analysis Significant difference of P<0.005 was recorded for root lengths for the three treatment levels. The pHs of the media (WSF and PW) at all levels were slightly acidic before exposure to A. cepa. After exposure of media to the plant the pH values increased from 6.67±0.06, 6.80±0.03, 6.86±0.03 to 7.30±30, 6.81±0.06 and 7.70±0.00 at 25, 50 and 100% WSF respectively. Produced water showed increase in values from 6.67±0.03 and 6.89±0.06 to 7.90±0.06 and 7.50±0.00 at 50 and 100% PW respectively, while exposure to 25% PW reduced pH from 6.66 to 6.40
Conclusion and application of findings: Based on the results, it is concluded that the effects of WSF and PW on the number and length of roots of onion plants were dependent on their concentrations, the higher the concentration the greater their effects on the plants. The results showed that PW of Ughelli East crude oil was more toxic than its WSF. These results show that there is the need for the government to implement measures to safeguard and reduce the effects of oil contaminated water on the environment.
Keywords: Produced water (PW), Water soluble fraction (WSF), crude oil, growth, catalase activity and Allium cepa.
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