Mercury is a toxic element, hazardous to both people and the environment. It is released into the atmosphere by many processes, particularly mining and refining processes. The Oil and Gas sector of the Mining and Minerals Industry is currently experiencing issues with mercury in waste water after the crude oil has been processed.
The aim of this thesis is to determine the effectiveness of various mercury removal methods. The processes investigated within this thesis include ion exchange, co-precipitation and activated carbon adsorption. The hypothesis for this thesis is: “A significant percentage of mercury and mercury complexes can be removed from waste water using ion exchange, co-precipitation and activated carbon processes.”
Mercury removal experiments involved determining mercury adsorption on activated carbons (Bio Nuchar 90 and Nuchar RGC 40) and ion exchange resin (Amberlite MB1) at flowrates of 1, 5 and 10 mL/min, and using precipitation addition rates of 0.5, 1 and 10 g/100mL of aluminium sulphate. Comparison studies were conducted between the activated carbons supplied. Media degradation studies were also conducted using Amberlite MB1 and Bio Nuchar 90, to investigate the adsorptive capabilities of the media.
These experiments involve mercury and therefore have the potential to be hazardous to both people and the environment. The potential risks and hazards have been assessed and appropriate controls established prior to conducting any experiments.
The results for mercury adsorption, show Bio Nuchar 90 activated carbon is more effective over the range of flowrates tested. The activated carbon comparison studies showed Nuchar RGC 40 was more effective for mercury removal than Bio Nuchar 90. Precipitation studies were unsuccessful at removing mercury from the aqueous solution.
From the results, activated carbons are more effective at higher flowrates, and appear more suitable for industrial applications. Further research and testwork is required to determine the adsorption capabilities of activated carbons and ion exchange resins for mercury removal from aqueous solutions.