The cooling water system of a power generation site had become contaminated with hydrocarbon pollution.

This circuit, with a volume of 180 m³ (234 yd³), had a total oil and grease concentration of 320 mg/l with a maximum target of 10 mg/l, i.e. a target decrease of 97 %. The objective was to intervene effectively on this circuit without stopping production.

CTP environnement's solution consisted of diverting a fraction of the flow to a temporary treatment plant, then reinjecting the treated water into the refrigeration circuit.

The diverted flow, of the order of 1 m³/h (4,4 gpm), is insignificant for cooling; this meant the operation was possible without disruption to the system.

The temporary treatment system deployed by CTP environnement consisted of an oil separator, a bag filtration stage, and a finalising stage on activated carbon.

This system allows a widespread reduction of the total, soluble and insoluble, oils and grease.

The installation, fully automated and secure, also allowed an exceptionally economical and continuous 24h/24, 7d/7 treatment.

Key project figures :

• 575 hours of treatment
• 60 litres of oil recovered and recoverable
• 99% reduction on a target of 97%