A pilot study of sorption filters to remove non-particulate organic pollutants in stormwater

Organic pollutants (OPs) occur in urban stormwater as sorbed to particles, and in dissolved and colloidal forms. In this study, a pilot plant with column bed-filters of sand in combination with granulated activated carbon (GAC), peat and bark was used to investigate the removal of non-particulate OPs from stormwater. Bark, peat and GAC filters showed 60-100% reduction of aliphatics, aromatics and naphthalene when incoming water was spiked with contaminated sediment and diesel, and the peat filter showed 70% reduction of aromatics and naphthalene during heavy rain events. Sufficient water flows through the filters were difficult to achieve and improvements of the hydraulics are recommended