What is off-gas treatment?
Some of the physical ground remediation processes, such as soil vapour extraction and air sparging, can result in the generation of concentrated vapours, which require treatment. We frequently use the following methods of off-gas treatment.
Granular activated carbon has the ability to remove a wide range of contaminants from the gaseous phase. We generally use this technology for off-gas treatment on remediation sites with low to medium concentrations of off-gas, and on relatively short term contracts.
We use air biofilters on longer term projects where the off-gases are readily degradable (e.g. petroleum hydrocarbons). These biofilters require careful monitoring for moisture content and other parameters for optimum efficiency. A larger footprint is generally required for the plant than activated carbon vessels but biofilters are an ideal, long term, cost effective solution.
Catalytic oxidation systems can be cost effective in the event that contaminant concentrations are high, as this would lead to high consumption of activated carbon. We can offer you a cost/benefit analysis between the use of catalytic oxidisers and other forms of vapour treatment, such as activated carbon and biotreatment.