Abstract: A liquid purification system for treating liquids such as water or sewage effluent in which a sealed casing has a plurality of corrugated panels therein dividing the casing into a plurality of sections. Liquid which may already have been partially treated is sprayed against or caused to flow onto each side of each corrugated panel and against the side walls of the casing and allowed to run down the panels and casing walls in a thin layer. The casing is filled with ozone under pressure and may have ultraviolet tubes placed between each pair of panels so as to permeate and disinfect the liquid at the bottom of the casing is pumped through an output pipe and through a filter system and may have additional treatment.