Developing a treatment method for oil contaminated mining sites

Abstract

The purpose of this study is to develop a cheap method that can be utilised by Metal Companies at its Site XY to decontaminate oil-contaminated soils. Oil spillages are a serious environmental threat since oil takes a long time to decompose in the soil. The heavy industry, more especially the mining sector, generates many spillages from its operations which can lead to a deviation from the environmental regulations such as the National Environmental Management Standards Act 107 of 1998. The Act gives the Ministry of Mineral Resources and Environmental Affairs the power to suspend mining activities and mining rights if there is a contravention of the constitutional directive to guard the environment by the respective prospecting or mining organisation (Vinti, 2018). Many mines prefer to seek third-party organisations' services to treat the contaminated soil, which comes at a higher cost. Metal Companies is one such organisation that still relies on procured services to treat oil-contaminated soil. In this study, samples from Site XY of Metal Companies were treated using some of the common methods that have been applied in other places as reported in the literature studies. A sample weighing 36 kg was collected from Site XY after which it was split into eight samples each weighing 4.13 kg. These samples were used to test eight different bioremediation methods over three months. The results from the eight treatment approaches were used to measure the depletion of oil and determine if the improvements were helping in making Site XY comply with the environmental regulations. The statistical evaluation methods used to analyse the results proved that organic reagents were more effective at decontaminating the soil, making the process cost-effective if in-house treatment is to be considered. The study was conducted in winter, and a drop in the rate of oil-depletion was observed in the fourth week from the two of the most effective methods. Recommendations were made to review the reagents and preferred treatment seasons at that stage. The costing methods for projecting future decontamination costs were developed to allow the mining sites to utilise internal resources for cleaning the oil rather than outsourcing the clean-up services. It was also recommended that the cost sensitivity analysis be conducted at all stages of the projects to identify activities and methods that lead to a waste of resources.