A cyclonic flotation system may be used to separate oil, grease, solids and other suspended matter from produced water by a combination of flotation and centrifugation in a separator cyclone. In exemplary embodiments, the apparatus comprises compressing a lower density gas in a liquid medium, allowing the gas to naturally rise to the surface of the liquid medium and then capturing the energy generated by the surfacing gas. The converging lens not only provides hermetic sealing for the housing, but also converges light before the light strikes the active area of the image sensor.