Article history

A toxicity test is carried out to select the contaminant concentration that a plant can tolerate in phytoremediation. We focused on the ratio of plant numbers to the total mass of contaminant as the factor for selection of contaminant concentration, nature of soil type and plant species in a diesel phytoremediation project. Based on the results of a preliminary test, Scirpus grossus could survive when the ratio of plant numbers to the total mass of diesel was more than 0.15 for 3 % (Vdiesel/Vwater) after 14 days of exposure in a sub–surface flow system (SSF) containing 780 mL of diesel contaminated water with 33 % percentage of withered plants. In a phytotoxicity test containing 7 L of diesel contaminated water, S. grossus could also survive with the ratio more than 0.07 for 2 % (Vdiesel/Vwater) for 72 days of exposure with 36 % percentage of withered plants. Based on the results of the preliminary and phytotoxicity tests, selection of diesel concentration in pilot scale containing 500 L of diesel contaminated water with 50 plants was fixed. Based on a minimum ratio of 0.05 from the preliminary and phytotoxicity tests, three diesel concentrations were selected to be 0.1, 0.175 and 0.25 % to evaluate the performance o