The development of biotechnology for water purification from toxic hexavalent chromium by duckweed plants (Lemna minor L.)

The problem of environmental pollution

As chromium compounds were used in dyes and paints and the tanning of leather, these compounds are often found in soil and groundwater at abandoned industrial sites, now needing environmental cleanup and remediation per the treatment of brownfield land. Primer paint containing hexavalent chromium is still widely used for aerospace and automobile refinishing applications.

World Health Organization recommended maximum allowable concentration in drinking water for Cr (VI) is 0.05 mg/l.

• Duckweed plants survive in a medium containing Cr(VI) in concentration up to 4mM.
• Increasing of Cr(VI) concentration up to 8 mM is critical: plants die but can reduce toxic Cr(VI) to nontoxic Cr(III) by plant metabolites