Performance of Field Based Activated Carbon Systems for Odour Control

Community tolerance for odours from sewer infrastructure is lessening, providing pressure to wastewater utilities to target and treat odour emissions from sewer networks. Gas phase odour abatement systems within sewer networks typically target hydrogen sulfide (H2S) as an odorant and overall odour indicator. However other compounds can occur naturally, or be present from trade waste, that are either odorous themselves or may impact on the performance of odorant removal in odour abatement systems. Activated carbon (AC) systems adsorb most contaminants during their lifetime until most active sites are depleted. Samples from the inlet and outlet of 6 AC filters in Sydney and Melbourne (Australia) were taken monthly over 18 months and analysed for volatile sulfurous compounds (VSCs) using gas chromatography (GC) coupled with a sulfur chemiluminescence detection (SCD). H2S was measured by Jerome 631-X hydrogen sulfide analyser for each sample. Each sample returned approximately 14 VSCs. After screening the data for wet weather and cooler periods, 6 VSCs were studied further. This paper evaluates and compares the performance of 6 activated carbon filters for each compound identified and each appropriate grouping of compounds. H2S and methyl mercaptan were found to be removed well, yet dimethyl disulfide was found to have a negative removal more often than it had a positive removal. Dimethyl sulfide and dimethyl trisulfide also suffered from negative removals, yet not as often as dimethyl disulfide. Carbon disulfide was removed as often as it was released.