Sorption of Phosphate on Douglas Fir Biochar Treated with Magnesium Chloride and Potassium Hydroxide for Soil Amendments

Article Authors: Beatrice Arwenyo 1,2 Chanaka Navarathna 1, Naba Krishna Das 1, Addie Hitt 1, Todd Mlsna 1,*


With increasing climate variability, a sustainable crop production approach remains an indispensable concern across the globe. In this study, P retention/availability of MgCl2.6H2O/KOH modified Douglas fir biochar was assessed. The MgCl2·6H2O/KOH treated Douglas fir biochar was prepared by sequentially treating Douglas fir biochar with magnesium chloride and potassium hydroxide solutions. The biochar’s surface area, pore volume, morphology, and elemental compositions were determined using BET, SEM, SEM/EDS, and powder X-ray analyzes. Both surface area and pore volume were reduced by more than 97% following modification. Similarly, the morphology and elemental compositions changed after modification. The maximum P adsorbed corresponding to Langmuir–Freundlich model was 41.18 mg g−1. P sorption on biochar soil mixture was pH dependent. More studies are required to establish the field applicability of P-laden MgCl2 ·6H2O/KOH-modified Douglas fir biochar as a soil additive.

Bibliographical metadata

DOI 10.3390/pr11020331
Related Faculties/Schools

1Department of Chemistry, Mississippi State University, Mississippi State, MS 39762, USA
2Department of Chemistry, Gulu University, Gulu P.O. Box 166, Uganda