Phytoremediation of vanadium and nickel from wastewater using Acorus calamus

Abstract

Acorus calamus is an important medicinal plant in many cultures around the world. This plant’s recorded history reaches as far back as 287 BCE, where its main uses were water purification and as a medicinal “cure-all”. In part one, I examined the history of A. calamus, its applications in the modern world and propagation methods. The two main propagation methods I tested were via rhizomes and seeds. Rhizome growth trials were more successful in overall plant yield than the seeds. Rhizomes planted in peat had 57% plant yield, while the no-peat treatment had 40% plant yield. Part two of the study examined A. calamus ability and efficiency in extracting vanadium and nickel from experimentally treated waters. Vanadium and nickel were chosen for their importance in the environment and their enrichment in bitumen, specifically tailings ponds. Nickel is an important nutrient for plant survival and vanadium is not. Acorus calamus plants were grown in a hydroponic system with 188 plants grown inside a clean air growth chamber for three months. Every day the plants were treated with nickel-enriched solutions at three concentrations (0.0, 0.01, 0.10 mg/L) and vanadium (0.0, 0.025, 0.25 mg/L). At the end of three months, plant tissues were harvested and analyzed for metal concentrations. The results showed A. calamus extracted both vanadium and nickel from the contaminated waters with maximum values of 0.6 mg/kg and 16.3 mg/kg, respectively. Results indicate A. calamus would be an excellent candidate for phytoremediation at contamination levels well above what is found naturally occurring in Alberta’s water sources.