Physiochemical, Structural Characteristics and Effect of Temperature on Coconut Husk Biochar’s Immobilization and Plant Phytoavailability of Chromium in Different Soils

Abstract

Coconut husk waste can be utilized to generate carbon-rich charcoal clean up contaminated soil. Consequently, the objective of this paper was to assess the Physiochemical and Structural Characteristics, Effect of Temperature and Plant Phytoavailability of Coconut Husk Biochar (CHB) Immobilization of Chromium in Different Soil Types using appropriate standard procedures. Data obtained show that the phytoavailable Cr fraction in the soil varied between 20 and 35 percent. At lower temperatures, CHB proved appropriate for immobilizing Cr in acidic soil. However, the point of zero charge measurements (pHpZC≈7.5, 7.8, 8.2, and 9.0) indicated CHB could effectively bind positively charged Cr hydroxo complexes at the pH of the calcareous soil; hence, the application of CHB is unnecessary due to the low solubility of these species. The These findings demonstrated that CHB had a higher sorption capacity with a lower pyrolytic temperature because it had more chemical groups on its surface than high-temperature CHBs. Moreover, CHB's restricted solubility is eliminated because it efficiently binds Cr hydroxo complexes with a positive charge at the pH of calcareous soil. While CHB makes Cr more immobile, Cr is mobilized in acidic soil.