Sorption of organic contaminants and nutrients onto rain garden soil amended with activated carbon

Raingardens may improve stormwater quality e.g. through pollutant sorption to soil. The aimof this study was to determine if adding activated carbon, a highly efficient sorbent, to rain garden soil can enhance the removal of organic pollutants and nutrients. Batch tests show that the activated carbon is efficient in sorbing hydrophobic organic pollutants, nitrate and phosphate. However, only the organic pollutants are removed in column tests where the activated carbon is mixed with soil. The low adsorption of nutrients in column experiments is likely due to competition for adsorption sites on the carbon surface with organic matter leached from the soil.