Adsorption of Metformin on Activated Carbon Produced from the Water Hyacinth Biowaste Using H3PO4 as a Chemical Activator

Water hyacinth biomass was used for the synthesis of activated carbons in process chemical activation with H3PO4, followed by controlled carbonization. The study investigates effect various impregnation weight ratios H3PO4 and dry (0.5–3.0), as well different carbonization temperatures (T = 400–800 °C), on surface characteristics produced (AC). carbon obtained an ratio 1.5 a temperature 600 °C (1.5 AC/600) showed highest values specific area 1421 m2 g−1, representing selected adsorbent metformin removal. chosen sample characterized elemental analysis, adsorption–desorption isotherms nitrogen at −196 °C, via FTIR spectroscopy SEM method. modeling experimental adsorption data that adsorption: (i) can be best described Langmuir isotherm model, value qmax 122.47 mg g−1; (ii) led pseudo-second order kinetic model; (iii) is spontaneous (ΔG° −3.44 kJ mol−1) endothermic (ΔH° 8.77 process. A desorption has shown 92% successfully desorbed presence 0.1 MHCl/ethanol mixture (volume 2:1). recovery 84%, after five successive cycles, indicated AC/600 potential to applied real systems water treatment.