Abstract
Phytoremediation of hydrocarbon-contaminated soils is a challenging process. In an effort to enhance phytoremediation, soil was artificially contaminated with known concentration of light crude oil containing Total petroleum hydrocarbon (TPH) at a concentration of 75 gkg−1 soil. The contaminated soil was subjected to phytoremediation trial using four plant species (Oryza longistaminata, Sorghum arundinaceum, Tithonia diversifolia, and Hyparrhenia rufa) plus no plant used as control for natural attenuation. These phytoremediators were amended with concentrations (0, 5 and 10 gkg−1 soil) of organic manure (cow dung). Results at 120 days after planting, showed that application of manure at concentrations of 5 and 10 gkg−1 soil combined with an efficient phytoremediator can significantly enhance reduction of TPH compared to natural attenuation or use of either manure or a phytoremediator alone (p<0.05). The study also showed that a treatment combination of manure 5 gkg−1 soil, with a phytoremediator gives a similar mean percentage reduction of TPH as manure 10 gkg−1 soil (p>0.05). Therefore, the study concludes that use of phytoremediators and manure 5 gkg−1 soil could promote the restoration of TPH contaminated-soils in the Sudd region of South Sudan.
Highlights
Crude oil activities often lead to changes in the functioning of the soil ecosystem [1, 2]. e crude oil products contaminate soil leading to deficiency of the much needed nutrients for normal functioning of plants [1, 3]
Ough Ruley et al [35] ascertained four plant species (O. longistaminata, S. arundinaceum, T. diversifolia, and H. rufa) as prominent phytoremediators, this study confirmed that augmentation with cow dung led to a marked improvement in the plant growth characteristics. ere were least significant differences between treatments without manure and those with manure in terms of both plant height and dry weight (p < 0.05). e improvement in plant height and dry weight content is attributed to the restoration of lost nutrients by addition of cow dung since it contains high nutrient composition providing polluted soil with (b) Figure 2: Continued
O. longistaminata, S. arundinaceum, T. diversifolia, and H. rufa become more viable phytoremediators when augmented with cow dung. is assertion rhymes Oyedele and Amoo [33] that addition of cow dung manure improves on the calcium, magnesium, phosphorus, potassium, and nitrogenous contents which are vital elements for better growth of plant species
Summary
Crude oil activities often lead to changes in the functioning of the soil ecosystem [1, 2]. e crude oil products contaminate soil leading to deficiency of the much needed nutrients for normal functioning of plants [1, 3]. E crude oil products contaminate soil leading to deficiency of the much needed nutrients for normal functioning of plants [1, 3]. Studies such as [3, 4] have provided proof that crude oil contaminated soils have less content of nitrogen and phosphorus. Different approaches; physical, chemical, and biological have been undertaken. Some of these are expensive while others have harmed the environment, soil health and human livelihoods [3, 7, 8]. As indicated earlier, contaminated soils have deficient nutrients. Addition of supplementary nutrients such as organic manure is necessary [14, 15]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
