Adsorbents for the removal of contaminants from stormwater

Conference poster, 2015

Contaminated urban runoff is a major cause of concern for water quality and aquatic ecosystems worldwide. Recent research shows that stormwater often contains metals and emerging organic contaminants at levels exceeding environmental quality standards. To comply with quality guidelines for receiving waters, stormwater treatment is considered to be critical. Filtration of stormwater through an adsorptive material is one of the most promising techniques for removal of particulate, colloidal and dissolved pollutants. The aim of this research was to use laboratory-based experiments to determine the removal capacity of selected sorbents for organic pollutants and metals found in stormwater. The ideal sorbent should be efficient in removing pollutants, inexpensive, abundant and easily accessible. A variety of materials, including minerals, wood- and bark-based media, were subjected to batch tests. By comparing the capacity of a range of sorbents under identical laboratory conditions, the most promising sorbent can be identified. The study revealed that cellulose and minerals adsorbed organic pollutants to a negligible degree. However, these materials may serve as efficient adsorbents of metals because of their potential to attract cations. Sawdust and bark efficiently and promptly sorbed organic compounds, whereas their capacity for metals was found to be low. Activated carbon produced from sewage sludge exhibited substantially higher adsorption capacity for organic pollutants than the wood- and bark-based media tested.