The ratio of plant numbers to the total mass of contaminant as one factor in scaling-up phytoremediation process

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 of pilot reed bed to remediate diesel. through the pilot study,the concentrations have resulted 10,20 and 30% withered plants in the respective diesel concentration. the ratio of plant numbers to the total mass of contaminant must be considered as one factor to determine the phytotoxicity effects of the contaminant concentration in scaling-up a reed bed system for phytoremediation process. © 2015 penerbit utm press. all rights reserved.