Removal of hexavalent chromium in wastewater using fava bean-based activated carbon with bimetallic Fe⁰-Cu

Hexavalent chromium [Cr (VI)] is a highly toxic compound that has a carcinogenic effect on human health when humans are exposed to high levels. Chromate pigments in dyes, inks, plastic, and paints are the primary sources of industrial hexavalent chromium. Hence, this study focuses on removing Cr (VI) from polluted water using eco-friendly materials like fava bean peels and their formulated activated carbon. As a new method, the prepared fava bean peels and their activated carbon are mixed with a bimetallic nano-zero-valent to investigate how this synthesized adsorbent affects the adsorption of Cr (VI). The duration of contact is altered at a concentration of 100 ppm of Cr (VI) and a shaking rate of 120 rpm, ranging from 15 to 180 min. The concentration varies from 25 to 500 ppm to investigate the impact of concentration on the effectiveness of Cr (VI) removal. At the first screening, an experiment is performed on the different materials to select the potent materials that achieve a higher Cr (VI) removal percentage. The chemically activated carbon with phosphoric acid has a maximum removal capacity of 186 mg/g at pH = 3, with a contact time of 180 min, shaking speed of 120 rpm, ambient temperature, a 25-ppm Cr (VI) dye solution, and a dosage of 1 g/l. The chemically activated carbon with sulfuric acid has a maximum removal capacity of 295.7 mg/g at pH 3, a contact time of 180 min, a shaking speed of 120 rpm, an ambient temperature, a 25-ppm Cr (VI) dye solution, and a dosage of 3 g/l. The isothermal results demonstrate the importance of chemisorption, which significantly affects effluent concentration. Response surface methodology (RSM) and artificial neural networks (ANN) are two techniques used in data analysis and modeling.