An Artificial Channel Purification Experiment for Arsenic-rich Drainage Water from the Abandoned Mine by using Eleocharis acicularis

Abstract

An artificial channel purification experiment for arsenic-rich drainage water was conducted to investigate the feasibility of phytoremediation by using Eleocharis acicularis. In the experiment, 15 m2 of Eleocharis acicularis mats were laid in an artificial channel in two days. Two sessions of artificial flow were implemented by leading 100 L of mine drainage water containing 7.45 mg/L of arsenic into the channel each time. The arsenic concentration in the Eleocharis acicularis was measured using samples collected at 0 m, 25 m, and 50 m along the channel. As a result of experiments, the arsenic concentrations of the outflow for the two sessions were 1.62 mg/L and 3.12 mg/L. This shows that the arsenic concentration decreased during two sessions, whose flow totalled 200 L. The initial concentration of arsenic in Eleocharis acicularis was 0.18 mg/kg at 0 m point, 0.06 mg/kg at 25 m point and 0.11 mg/kg at 50 m point. After two inflows, the arsenic concentration of Eleocharis acicularis increased from 88.5 mg/kg to 105.0 mg/kg at 0 m, from 29.6 mg/kg to 52.8 mg/kg at 25 m, from 7.2 mg/kg to 37.8 mg/kg at 50 m, respectively, indicating that Eleocharis acicularis absorbs arsenic. This paper describes the results of an artificial channel experiment in which water containing arsenic was purified by using Eleocharis acicularis.