Bentonite as a Potential Adsorbent for the Removal of Copper Ions from the Galvanic Industry Wastewater

Among the main pollutants of natural water resources are heavy metals that arrive from various sources. Waters polluted with heavy metals pose a great danger to human health and the environment, which is why special attention is paid to them. Therefore, in this work, natural bentonite, which is abundant in Bosnia and Herzegovina, was used for the removal of Cu (II) ions from the wastewater of the galvanic industry. Before and after the adsorption process, a physicochemical characterization of the bentonite was carried out, and the experiment was carried out in batch conditions on synthetic and real water samples. The influence of process parameters such as pH value, temperature, concentration, contact time, and mass of adsorbent were examined. The analysis showed that bentonite can be used to remove Cu (II) ions from the galvanic industry wastewater and that it shows great efficiency as an adsorbent to remove these ions. From the obtained results, it can be seen that the highest adsorption capacity is achieved at a concentration of 10000 mg/L, that is, the highest removal efficiency is at pH 5, a mass of 1 g, and a time of 60 min. Kinetic adsorption data showed the best agreement with the pseudo-first-order model for the real sample, and the pseudo-second-order model for the synthetic sample, while the best results of the adsorption isotherm were given by the Freundlich isotherm model.