Abstract: A process and apparatus for the purification of effluent waters containing organic pollutants by a rapid biological oxidation (activated sludge) process characterized in that the liquid to be purified is introduced into a tank containing a liquid having a high biomass concentration. Liquid is drawn from the tank and reintroduced through an aerating device in such a way as to produce rotation of the liquid in the tank to the extent that a vortex is produced on the surface. A part of the liquid taken from the tank is strayed on to the vortex and a proportion passed to a mechanical separating means that separates sludge from the liquid and a proportion of the separated sludge is reintroduced directly in to the tank. The liquid from which the sludge has been removed constitutes the purified effluent.

Abstract: A process for extracting valuable wool wax as a product having the specifications of lanolin from wool grease as found, for example, in the liquor from the scouring of raw wool. The process, apart from removing wool grease/wool wax from wool scouring effluent, avoids the production of pollutants in the extraction process, and in the case of the treatment of wet sludge containing wool grease produces a virtually grease-free solid product suitable for disposal as an environmentally safe soil.

Abstract: Apparatus for measuring and controlling the relative humidity of exhaust air from an industrial drier in which exhaust air is passed across a dry bulb and a wet bulb thermocouple from which a voltage is derived providing a measure of the relative humidity in the air in the sample. This voltage is used to control the amount of exhaust air from the drier to atmosphere. The wet bulb thermocouple is cyclically dipped in a bowl of water under the control of a timer system of the voltage to control the amount of exhaust air discharged until the wet bulb thermocouple is equilibrated with the exhaust air sampled after dipping.