Abstract: There is disclosed a novel nozzle assembly comprised of a tapered liquid passageway and a tapered gas passageway of diminishing cross-sectional areas disposed at an angle of from 0.degree. to 90.degree. to one another meeting at the enlarged end of a gas-liquid mixture passageway of diminishing cross-sectional area to an outlet end thereof. Accordingly, separate streams of a pressured gas and a pressurized liquid are introduced into the respective gas and liquid conduits whereby the gas and liquid are accelerated to a high velocity while minimizing velocity head loss and admixed at converging angles to achieve immediate high forward velocity and thus gas-liquid dispersion with the resulting gas-liquid mixture being subsequently accelerated with minimum pressure losses to achieve further gas-liquid dispersion and thus, microbubble production from controlled volumes of gas and liquid.