The heavy metal adsorption capacity of stalk biochar in an aqueous phase

Abstract

Several heavy metal ions including chromium(II), nickel(II), copper(II), zinc(II), cadmium(II), and lead(II) have gained attention due to their common occurrence in recent years. At medium-high temperatures, rice plant stalk (Oryza sativa L.) biochar, cassava stalk (Manihot esculenta Crantz) biochar and reed stalk (Phragmites Trin.) biochar automatically undergo pyrolysis, and the resulting biochar can be used as an adsorbent of heavy metal ions. While maintaining the pH and temperature of the solution and the dosages of biochar, the adsorption capacity of heavy metal ions in biochar under different treatment times (1 h, 6 h, 12 h, 24 h, 48 h, 72 h, and 96 h) were assessed. The physical and chemical characterization of the biochar was also performed. In this article, biochars produced from two common grain crop stalk (rice plant and cassava) and cash crop stalk (reed) were estimated as potential adsorbents for the removal of heavy metal ions from the contaminated solution.