Efficiency of arsenic removal from soil by colocasia esculenta (L.) schott (dark violet and green)

Abstract

To investigate growth rate of Colocasia esculenta (L.) Schott (dark violet and green) in arsenic contaminated soils, to find the level of arsenic accumulation in parts of Colocasia esculenta (L.) Schott, and to compare arsenic removal efficiency from soil by both Colocasia esculenta (L.) Schott. Experimental soil was contaminated with disodium hydrogen arsenate at concentrations of 0, 50, 75, 100, 125, and 150 mg As/kg soil dry weight. All data were recorded every 15 days, on 6 consecutive occasions over a 90-day trial period. From the results, of Colocasia esculenta (L.) Schott (dark violet) could grow well under all concentration of arsenic, with 100% survival. In addition, amount of arsenic accumulated in root was more than that in corm, lamina, and petiole. Maximum arsenic removal rate was 0.07% in 100 mg As/kg soil dry weight and its efficiency increased throughout the experiment. Another test for Colocasia esculenta (L.) Schott (green), the result showed similar to Colocasia esculenta (L.) Schott (dark violet), Colocasia esculenta (L.) Schott (green) could grow well in all tested conditions. Amount of arsenic was increased in petiole, lamina, corm, and root, respectively. Maximum efficiency of arsenic removal was 0.06% in 125 mg As/kg soil dry weight and its efficiency increased by time of growth as well. In conclusion, the efficiency of both Colocasia esculenta (L.) Schott was not different; in addition, all plants of the experiment can survive under arsenic concentration ranged from 0-150 mg As/kg. Consequently, Colocasia esculenta (L.) Schott is more appropriate for Thailand and should be recommended for soil improvement in case of arsenic contamination.