Phytoremediation of Hexavalent Chromium by Azolla pinnata พัชรี สินธุนาวา และจันทร์เพ็ญ มะลิพันธ์

Abstract

Hexavalent chromium is a compound widely used in industry, contaminated in water, and causing environmental problems. Phytoremediation is a technology that uses various plants to adsorb contaminants from soil and water. Plants that can accumulate high amounts of heavy metals are called hyperaccumulators and one of them is the water fern A. pinnata. This study aimed to investigate the phytoremediation potential of  A. pinnata for the removal of hexavalent chromium from synthetic solutions. A. pinnata 50 g was cultured on synthetic solution containing hexavalent chromium ions at concentrations 0 (control), 1.1, 5.9, 12 and 53 ppm in 5l synthetic solution at pH 6.5-7.5 and temperature 28-30°C. A. pinnata was harvested at 5, 10 and 15 days and wet weight was obtained to determine relative growth and doubling time. During the 15 days of the experiment, biomass productivity and relative growth of A. pinnata were decreased by 28.39 - 89.22% in the treatments compared to the controls. The control has a doubling time of 6.24 days. The removal of hexavalent chromium by A. pinnata revealed that at initial hexavalent chromium concentration of 1.1, 5.9, 12 and 53 ppm, were respectively absorbed 0.33, 1.03, 2.70 and 4.00 ppm which was significantly different at 0.05 statistical level. These results suggest that A. pinnata could be considered for the removal of hexavalent chromium from water.