Removal of Cadmium (II) using water hyacinth (Eichhornia crassipes) biochar alginate beads in aqueous solutions.

This study involved examined the Cd2+ sorption dynamics of an alginate encapsulated water hyacinth biochar (BAC) generated at different temperatures and modified using ferric/ferrous sulfate (MBAC). The maximum Cd2+ sorption occurred at a pH of 6 and at a solution temperature of 37 °C. Sorption equilibria for the biochar-alginate capsule (BAC) and modified biochar-alginate capsule (MBAC) treatments fit both the Langmuir (R2 = 0.876 to 0.99) and Freundlich (R2 = 0.849 to 0.971) equations. Langmuir isotherms had a better fit than the Freundlich isotherms, with maximum sorption capacities ranging from 24.2 to 45.8 mg Cd2+ g-1. Larger KL values in Freundlich modeling suggest strong bonding of the BAC and MBAC sorbents to Cd2+, with values of KL in the MBAC treatments ranging between 31 and 178% greater than the BAC treatments. Cd2+ sorption followed pseudo first-order kinetics (R2 = 0.926 to 0.991) with greater efficiency of removal using treatments with biochar generated at temperatures >500 °C. Results from this study highlight the potential for biochar-alginate capsules derived from water hyacinth to be effective for the removal of Cd2+ from wastewaters. PMID: 32559880 [PubMed - as supplied by publisher]
Source: Environmental Pollution - Category: Environmental Health Authors: Tags: Environ Pollut Source Type: research