Selection framework for the treatment of sewer network emissions

Increasing urban growth and lifestyle expectations have led to an increase in public complaints against odours from sewer infrastructure. Gas phase odour abatement in sewer networks, particularly at sewer pumping stations, is most commonly achieved by using biofilters, biotrickling filters or activated carbon filters. When odour complaints are received, a typical response is to close vents, leading to biogenic corrosion in sewers, which increases operating costs. A three-year study of the performance of odour control systems has allowed a comparison of the removal efficiency for the most common treatment systems. An analysis of the treatment system robustness has also been conducted. It has been found that biofilters, biotrickling filters and activated carbon all remove hydrogen sulfide and methyl mercaptan, however residual odours can still lead to complaints particularly during 'spikes' of the inlet, where a particular compound's inlet concentration is high. This analysis has led to an odour abatement technology selection flowchart being proposed for the treatment of sewer network emissions.