Biomass Enriched with Minerals via Biosorption Process as a Potential Ingredient of Horse Feed

In the present work, dry plant biomass that is commonly used in horses feeding: alfalfa, chopped grass pellets and chopped grass was used as a biosorbent of microelement ions: Cr(III), Zn(II), Cu(II) and Mn(II). Biosorption process was used to potentially enhance supplementation of minerals in horses diet. In order to characterize the biosorption properties of the examined biomass, preliminary experiments (kinetics and equilibrium studies) were conducted with Cr(III) ions. The effect of pH and initial metal ions concentration (C-0) on the biosorption capacity (q) was investigated. On this basis, the best experimental conditions were chosen (pH 5, C-S 1.0 g/L (biomass content), C-0 200 mg/L). For them, biosorption of Mn(II), Zn(II), Cu(II) ions was carried out in a periodic and continuous system (biosorption column). Equilibrium of the biosorption was described using Langmuir equation. The mineral composition of the raw and enriched biomass was also examined using ICP-OES, as well as SEM-EDX technique. In general, the best biosorption properties were observed for alfalfa. The maximum biosorption capacity for Zn(II) was 27.5 mg/g, for Cu(II)-38.5 mg/g, for Mn(II)-13.6 mg/g and for Cr(III)-33.2 mg/g. Therefore, the biomass of enriched alfalfa can be recommended as a feed supplement for horses.