M. Tech. / The mechanism of microwave assisted waste oil and water emulsions destabilisation is analysed. The broad overall features of the microwave system to break emulsions are established and the design specifications of each constituent component are set. The type of well suited microwave cavity is selected. After analysis, the multimode cavity proves to be a suitable choice. The established overall dimensions of the cavity are set and used to visualize the field pattern in the treatment chamber. Some MATLAB routines are written and used to enhance the visualization of the field pattern inside the microwave cavity. The individual excited modes are first visualised, followed by the resultant electric field. The detailed descriptions of the drawing are then finalised and the microwave system constituents selected. The cavity is manufactured and tested for leakage. The test shows that the cavity is watertight.