Passive Odour Control Units


Passive odour control units can be very useful to eliminate odours from smaller odour sources. In some situations like manholes, air relief chambers,… it is impossible to install a fan driven odour control unit. There might be no electricity available to run a fan or the OCU has to be installed below the street level. The activated carbon systems are commonly used sewage applications for the removal of H2S. In these units, catalytic activated carbon is used to be able to regenerate the carbon in situ with water.

When passive odour treatment systems are installed, special attention must be paid to the sealing of the chamber. All accesses, cable conduits, etc. must be fully sealed, allowing the foul air only to breathe through the carbon filter.

Ipec offers a wide range of passive odour control units
  • Manhole buckets will trap odours from sewage gravity lines before the escape to the surroundings. The buckets can be positioned under the manhole cover so there will be no visual disturbance . If an existing manhole is provided with a sealing plate, manhole bucket can be integrated in the sealing plate. By reusing the corresponding sealing plate the air tightness can be guaranteed.
  • Above ground passive units can be used for several applications like vacuum pumps or air relief valves where discontinuously foul air escapes through venting. Note that the air that escapes is not diluted by fresh air which results in air flows with high odour levels and special care should be taken to the sizing of such systems.
  • Underground passive units: The complete unit can be installed underground. This can be done along the road site or if required even under the road, parking or any accessible area. For this heavy loading situations, Ipec designed a special two-wall GRP vessel with steel fibre reinforcement to allow the load of heavy vehicles on the underground unit. The underground unit will cause no visual disturbance and will take no above-ground space. The system can provided with spraying system for regeneration of the activated carbon in situ.

All these passive units can be installed with a water spraying system in the vessel for regenerating of the water regenerable activated carbon.