Odour control

Industrial gases can generate unpleasant odors which may disturb the surroundings of a site, even if the concentrations in the ambient are minimal. This is the case with polluted air containing nitrogen or sulphur-based compounds, aldehydes, ketones, acrylates and organic acids.

 

 

Applications

 

Industrial sector :

            - processing of animal by-products

            - processing of vegetable by-product

            - coatings

 

Waste processing sector :

            - solid waste

            - liquid waste 

 

 

Depending on the field of activity and the pollutants encountered, WATERLEAU France defines the appropriate ESOLAV, ESOBIO, ESOSORB, ESOCOV process which would best reduce or eliminate the unpleasant odors.

 

Biofiltration is increasingly used to abate the emission of noxious odors and hazardous volatile organic compounds originating from a very wide range of industrial processes. Because of relatively low operating costs compared to other abatement technologies, biofiltration often offers the most economical solution, especially in cases where gas flows are high and component concentrations are low.
Biological oxidation is the air equivalent to biological wastewater treatment. Biological treatment relies on the ability of micro-organisms to degrade a wide variety of organic compounds by oxidizing them to carbon dioxide, water and salts. 

 

Three principal biofiltrationsystems have evolved:


1. biofilter : BIOTON® biofilter
2. bioscrubber : BELAIR® biotrickling + biofilter
3. biotrickling filter : BIOWAVE® bioscrubber

 

 

BIOTON® biofilter

 

BIOTON® biofilter is WATERLEAU's proprietary biofilter technology. This technology was acquired from Monsanto EnviroChem Systems (MECS).

 

A contaminated air stream is ducted and routed to the BIOTON® biofilter system. The contaminated air stream first enters a humidification vessel and is drawn upward through a plastic packing material. As the air flows upwards, water flows downwards over the packing. Once saturated, the contaminated air enters the upper chamber of the biological oxidation vessel. The contaminated air passes downwards through the biological active media. Micro-organisms present in this water film oxidize the contaminants to innocuous end-products such as CO2, H2O, and common salts.
The once contaminated air collects in the bottom of the biofilter and exits the vessel. The cleaned air is finally discharged by a process blower to the atmosphere through a small air stack.

 

Schematic representation of a BIOTON® biofilter

 

 

Applications:

 Advantages:
  • Flavours and fragrances
  • Relatively low capital cost
  • Municipal wastewater treatment
  • Very low operating cost
  • Waste handling
  • High VOC and odour destruction
  • Composting
  • Environment friendly technology – no chemicals or supplemental fuels required 
  • Tobacco
  • Proven technology (>120 references)
  • Solvent users
  • High availability 
  • Food processing
  • Long life time of bed material
  • Chemical manufacturing

 

  • Solvent-based printing

 

  • Film production

 

  • Oilseed processing
  

 

 

BELAIR® biotrickling/biofilter


WATERLEAU has developed a two-stage biotrickling/biofiltration concept for treatment of VOCs and odours in off gases released for example in WWTP systems.

 

The concept, called BELAIR® biotrickling/biofilter is based on the experience of WATERLEAU in the field of physicochemical and biological air treatment (more than 150 references).

 

The air treatment system consists of two successive stages: a biotrickling filter for partial removal of H2S, VOC and dust as well as a prehumidification to a relative moisture content of 90-95% and as second step a biofilter for advanced destruction of organic and some inorganic (NH3, H2S) compounds.

The BELAIR® biotrickling/biofilter medium is a special mixture of sieved woodbark.

 

  

Schematic representation of a BIOTON® biotrickling/biofilter

 

Advantages


Two-stage process is more reliable
Additional humidification 
BELAIR® biotrickling/biofilter- special medium 
Low operational costs


BIOWAVE® scrubber

 

The presence of particulates in the contaminated air stream has often been a problem, which has necessitated treatment of the air stream in a separate system to remove them prior to biofiltration.

 

 

The BIOWAVE® scrubber is basically a variant of the bioscrubber, which includes the dust removal reverse jet system of the highly efficient DYNAWAVE® scrubber (MECS technology), a device that utilizes DuPont®'s Froth Zone technology for the removal of particulates and the absorption of gaseous pollutants.

 

The contaminated air stream flows downward through an inlet duct, counter current to a jet of water injected into the air stream via a relatively large diameter nozzle. Utilizing an appropriate liquid/gas ratio, a froth zone is created above the injector nozzle. Appropriate strains of micro-organisms with which the scrubbing water is inoculated break down the VOCs and odorous compounds, as in a conventional bioscrubber and the solids are removed from the system via the effluent discharge. Because of the large diameter of the reverse jet, the BIOWAVE® scrubber can handle sticky and/or abrasive dusts, and the level of turbulence ensures a very high efficiency of particulate removal.

 

Advantages 

 

no packing for mass transfer
no plugging