ETS carries out design, fabrication, installation and commissioning of it's organic media packaged BIO-F biofilter systems. Suitable for low to medium air flows (100 - 2,600m3/hr) and low H2S concentrations (1-10ppm average/10-40ppm peak concentrations), the BIO-F biofilters is well suited to small wastewater treatment plants and pump station applications. The BIO-F biofilter is based on the principal of immobilised fixed film microbiological technology where-by select bacteria are able to utilise contaminants in the air stream as a part of their energy pathway. A combination of Diffusion, Disassociation and Oxidation result in H2S being converted to Sulphate and Hydrogen.
The principal of biofilters has been with us for decades with the first systems simply pumping the odorous air into a soil bed allowing the naturally occurring bacteria to treat the contaminants. This however proved un-reliable as the soil bed was subject to weather effects allowing either the saturation or drying of the bed and plugging or by-passing of media.
Second generation systems improved reliability by creating better diffusion of the air into the soil bed (media would now include some form of bark or larger particle to reduce pressure) and providing the system with irrigation to ensure that the bed did not dry out, however again these systems fell short as acidic by-products started to decompose the media causing bed failure and creating an environment that inhibited biological activity.
Third and forth generations saw the continuous improvement in both the irrigation and media as alkali materials were added to reduce the impact of acidic by products and a better understanding of moisture control and it's impact on the biology became better understood. The problem of slime and excessive bacterial build-up in the air distribution duct remained a problem.
Led by research and development in the Netherlands, a biofilter was designed which eliminated the issue of weather effects by completely enclosing the system. This offered greater control of the environment inside the vessel meaning that the control of moisture, temperature and humidity could be controlled. The materials used for the media improved further and in a change that turned biofilters on there head literally the system was designed with the airflow directed to the top of the media. Meaning that the odorous air came into contact with the media surface where the moisture was added. This was the first down flow biofilter and is the principal from which our BIO-F biofilters draw their design inspiration.