Modeling the Effect of Petroleum Produced Water on Jatropha Curcas L. Growth at Nursery Stage for Biofuel Production

Abstract

Sudan is producing crude oil in resources-rich regions. With every single oil barrel that is produced, there are up to 10 barrels of water which are jointly produced. This water is highly polluted which can harm the environment, therefore a special treatment is needed before disposing the water. This research addresses the usage of the produced water in growing bio-fuel plants such as Jatropha Curcas L. The objective of this study is to examine the characteristics of the samples of the obtained water as well as to determine the effect of crude oil and NaCl concentrations on Jatropha Curcas L. The growth parameters such as stem height, stem diameter and number of leaves on sandy clay soil at Khartoum State, Sudan are also observed. The experimental treatments are simulated saline water of five levels in concentration in combination with five different levels of crude oil concentrations. Chemical analysis of water samples are obtained from Central Processing Facility (CPF) in Aljableen Town (White Nile State) showed that Sodium (Na) element has the highest level of concentration of about 1562 ppm, potassium (k), 79.15 ppm and salinity concentration of 2.80 g/L. No oil and grease were detected in the tested samples from Oil Facility. However, crude oil is added to the water in certain quantities during the experiment. The results showed a proportional relation between the stem height and salt concentration, but the oil concentration had a negative correlation with the stem height. The germination percentage was found to be 57.3% after 10 days of sowing the seeds. The tallest stem height of 14.1 cm during the experiment has been recorded with water oil content of 0.392 mL/L and 2.152 mL/L NaCl content. Statistics show that the highest mean stem height is 12.47 cm treated with simulated produced water of 1.176 mL/L of crude oil and 5.380 mL/L of NaCl while the severe damage to stem and leaves due to accumulation of oil particles has been recorded with simulated produced water of 1.568 mL/L of crude oil and 2.152 mL/L of NaCl salt. The output from the ANOVA shows that the stem height is changed significantly over levels of oil concentrations. Particularly, the stem height is negatively affected by high levels of oil concentration. A multiple regression model describing the relation between the Jatropha stem height and the concentrations of crude oil, NaCl and number of days was formulated as follows:

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