Arsenic and antimony bioremediation by Phragmites australis:Rizofiltration technology

Abstract

Arsenic is a ubiquitous element, present in the atmosphere as well as in the aquatic and terrestrial environments. It is an environmental<br><br>pollutant with high toxicity to organisms. Remediation of arsenic contaminated soils has become a major environmental issue.<br><br>Phyroremediation is an ecofriendly approach for remediation of contaminated soil and water. Phragmites australis, common reed,<br><br>characterized by elevated water detoxification capacity can be used in phytoremediation. In order to model a successful<br><br>phytoremediation strategy from polluted area, we collected Phragmites australis from five stations in arsenic polluted area, Chelpo, and<br><br>compared with samples collected from unpolluted area, Bazangan, northeast Iran. Arsenic was measured in different parts (root,<br><br>rhizome, stem and leave) of Phragmites australis using graphite furnace atomic absorption spectrophotometer method. Maximum<br><br>arsenic uptake in root, rhizome, stem and leave samples is 21.25, 18.5, 4.5 and 4.05 mg kg-1 respectively. The leaves were also<br><br>analyzed for Chlorophyll a, a/b and carotenoids by spectrophotometer method. In contrast to control samples chlorophyll a concentration<br><br>and chlorophyll a/b ratio decreased significantly (P≤0.05) .Whereas total carotenoids as an important antioxidant compound are<br><br>increased significantly from 0.65% to1.53 %( p≤0.01). We also measured Mn, Ca, Zn, Mg, P, Na, K and Fe concentrations in the<br><br>samples. The results show that the arsenic uptake by roots of P.australis mostly decreased uptake of nutrient elements, Mn, Ca, Zn, Na,<br><br>Mg and P (p≤0.01), however Fe and K concentrations in roots increased significantly (P≤0.05). It is concluded that common reed<br><br>(P.australis) qualifies as an arsenic hyperaccumulator and thus naturally has potential application in phytoremediation from arsenic<br><br>contaminated site.