Eradication of Chromium (VI) by Employing (Equisetum hyemale) Biomass

Abstract

Aims: Currently, a great alternative to try to bioremediate contaminated sites, mainly of heavy metals, is the use of natural biomass, with highly satisfactory results, among which are: fungi, bacteria, algae, agricultural waste of plants, and others. Our objective was analyzing the removal of Chromium (VI) by the Equisetum hyemale biomass, by a colorimetric method. Place and Duration of Study: Sample: Faculty of Chemical Sciences. Autonomous University of San Luís Potosí, S.L.P., between March and June 2024. Methodology: The biomass was obtained from the horse tail plant (E. hyemale), acquired in the Republic market of the city of San Luís Potosí, during the month of February 2024.  For obtain the biomass, the plant was washed during 24 hours in EDTA at 10% (p/v), and after 1 week with trideionized water, with water changes every 12 hours, and we analyze the removal capacity for Chromium (VI) (100 mg/mL) under different conditions. The pH of the solution was adjusted with 1 M H2SO4 and/or 1 M NaOH, before adding it to the biomass. Results: The most bioadsorption was at 8 hours, at pH 1.0, 1 g of biomass, 100 rpm, and 28°C. At a higher incubation temperature, the removal capacity increases, since at 60°C, 100% is removed after 4 hours in the same conditions. With respect to the heavy metal concentration, no differences were found in metal removal at 60°C, although a shorter incubation time was observed at 200 mg/L of the heavy metal, while at 28°C, to lower concentrations, is better the removal of the contaminant. Too, if we increase the biomass concentration, increase the efficiency of removal. Finally, this natural biomass, efficiently removal the metal of wastewater, after 10 days of incubation, 28°C, 5 g of biomass, because 86% of soil and 70% of wastewater, were eliminated from contaminated with 100 mg/g earth, and 100 mg/L of wastewater. Conclusion: This natural biomass obtained from agricultural waste, eliminate the heavy metal in solution, and can be a good alternative for their removal from industrial wastewater and contaminated soil.