Abstract: An automatic control apparatus for effecting the continuous removal of contaminants, such as volatile organic compounds (VOCs) from a process fluid, such as water used to wash print towels or the like. The apparatus includes a pump for circulating wash water from a washer to a treatment tank. A diffuser is provided for air stripping the contaminants from the wash water in the tank. The diffused gas is exhausted through a vent in the tank, and a contaminant emissions concentration sensor detects the composition of VOCs in the exhaust. A controller signals the pump to vary the circulation based on the emissions concentration detected by the sensor. The wash water is continuously recirculated to the washer until a predetermined emissions concentration is reached. A drain in the tank releases the treated wash water to the environment.