An Artificial Channel Experiment for Purifying Drainage Water Containing Arsenic by Using Eleocharis acicularis

This paper reports the results of an artificial channel experiment in which water containing arsenic was purified by using Eleocharis acicularis. The experiment was conducted to investigate the feasibility of phytoremediation by Eleocharis acicularis in civil engineering projects. In the experiment, 15 m2 of Eleocharis acicularis mats were laid in an artificial channel. Three sessions of artificial flow were implemented by leading 100.0 L of river water containing 0.234 mg/L of arsenic into the channel each time. The arsenic concentration of the leachate from the channel was analyzed. As the results of experiment, the arsenic concentrations of the leachate for the three sessions were 0.045 mg/L, 0.133 mg/L, and 0.249 mg/L. This shows that the arsenic concentration decreased during the first two sessions, whose flow totaled 200 L. The arsenic concentrations in the Eleocharis acicularis were 0.87 mg/kg, 1.01 mg/kg, and 4.16 mg/kg, which show that the plant absorbs arsenic. Moreover, it was found that the amount of sample water was reduced through evapotranspiration from the plant and the artificial channel.