Rhizoremediation of Hydrocarbon Contaminated Soils: A Case Study at Newmont Ghana Gold Limited (NGGL), Ahafo- Kenyasi

Loading...
Thumbnail Image
Date
2011
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
This study investigated the rate of degradation of Total Petroleum Hydrocarbon (TPH) and Oil and Grease in Hydrocarbon contaminated soil samples obtained from a mine site (Newmont Ghana Gold Limited) using Rhizoremediation technology with different levels of nutrient amendments for a native species. The levels of N (nitrogen) used were; in Compost (0.2%, 0.5% and 0.8%), Urea (0.2%, 0.5% and 0.8%) and Topsoil (0.2%, 0.5% and 0.8%). A Ghanaian native grass species Paspalum Spp from the (Poaceae) family was selected following the development of essential and desirable growth criteria. Vegetative parts of the species were subjected to ten (10) treatments in a Randomized Complete Block Design (RCBD) in three replicates. The plant-associated microbial community was examined in Paspalum Spp. The assessment of the influence of grass on the abundance and activity of microorganisms in the rhizosphere revealed a buildup of microbial communities over the period. This was assessed using the Freidman‟s test which showed that at p value of 5% rhizospheric samples from the different treatments were significantly different. Multiple comparisons showed how microbial populations built up in the rhizosphere for the different treatments.Treatments G(0.2% compost+ 3kg HCS) , H(0.5% compost+3kg HCS) and I( 0.8% compost+3kg HCS) showed no significant difference with regards to rhizospheric TPH and Oil and grease degradation levels whiles treatments E( 0.5% topsoil+ 3kg HCS) and F(0.8% topsoil+ 3kg HCS) also showed no significant difference in performance. Furthermore treatment A (0.2% urea+ 3kg HCS), B (0.5% urea+ 3kg HCS), C (0.8% urea+ 3kg HCS) and D (0.2% topsoil+ 3kg HCS) also showed no significant difference in terms of rhizospheric TPH and oil and grease degradation patterns. The presence of a single species successfully enhanced the removal of hydrocarbons from soil. Paspalum Spp subjected to compost levels( 0.5% and 0.8%) and topsoil levels (0.5% and 0.8%) showed significantly lower residual hydrocarbon concentrations than those treated with Urea after 80days (p< 0.00). A strong relationship between abundance of hydrocarbon degrading microorganisms in the rhizosphere and hydrocarbon biodegradation was demonstrated for rhizospheric samples with treatment G (0.2% compost+3kg HCS), H (0.5% compost+ 3kg HCS) and I (0.8% compost+ 3kg HCS) (p < 0.001). This study showed that Paspalum a native Ghanaian grass species could be a possible candidate for in situ rhizoremediation potential at field scale and that some level of amendment with 0.8% compost (N-level) can improve the effectiveness of the application.
Description
A thesis submitted to the School of Graduate Studies, Kwame Nkrumah University of Science and Technology, Kumasi, in partial fulfilment of the requirements for the award of the Degree of Master of Science in Environmental Science,
Keywords
Citation