Effluent water treatment utilising a combination of hydrodynamic shear and flotation technology for the specific application of wastewater from the oil and gas industry

Abstract

Water plays an important role in the petrochemical production and refining processes. The wastewaters released by these processes are often rich in petroleum pollutants, that requires significant treatment prior to disposal. Of particular importance is the processing of oil in water (o/w) emulsions. The processing and treatment of oil emulsions is focussed on breaking the emulsion and separation into the aqueous and oil phases for further appropriate disposal. The general approach is to optimise the processing to achieve relatively clean water, that can be recycled or discharged into the environment, whereas the oil is disposed of or recycled appropriately. The use of chemical coagulants and flocculants results in the degradation of the oil phase forming sludges as well as toxicity issues when using aluminium based coagulants.