Removal of barium and strontium from wastewater and radioactive wastes using a green bioadsorbent, Salvadora persica (Miswak)

The adsorption ability of Salvadora persica (Miswak) root powder was tested as a green biosorbent for the removal of barium and strontium from wastewater and radioactive wastes. The structure of the powder SP(M) and its chemical properties were characterized and evaluated by Fourier transform infrared spectrometry and scanning electron microscope morphology. The adsorption efficiency has been investigated as a function of pH, contact time, adsorbent dose, and initial metal ions concentration. The experimental data were analyzed using equilibrium isotherm, and kinetic models. The isotherm data agreed fairly well with Langmuir and Freundlich isotherm models. According to the Langmuir isotherm model, the maximum adsorption capacity was sufficiently high compared with many of the previously reported adsorbents and found to be 34.97 and 41.49 mg/g for Ba(II) and Sr(II), respectively. Miswak proved to be suitable and efficient biosorbent, environmentally friendly, cost-effective, and obtained from naturally and widely grown trees in many parts of the world.