China Nonferrous Metallurgy

Longnan City has a large number of zinc mines and zinc smelters, and has a large number of walnut green peel resources. Based on the adsorption of zinc ions by activated carbon, in this paper, walnut green peel was carbonized at different temperatures, the activated carbon was modified by NaCl, HCl and NaOH, and the adsorption effect of modified activated carbon on zinc ions in wastewater containing zinc was investigated under different conditions. The results showed that the walnut green peel carbonized at 500℃ had the best adsorption property, which was denoted as WP-500. WP-500 modified by NaOH had the strongest adsorption capacity for zinc ions, and the modified activated carbon was denoted as WP3-500. When the dosage of WP3-500 was 4g/L, the temperature was 30℃, and the time was 30min, the removal rate of WP3-500 for zinc ions was 81.11%, and the adsorption capacity was 10.14mg/g. The results of kinetic analysis show that the quasi-first-order kinetic model can describe the adsorption behavior of WP3-500 on zinc ions, which is mainly controlled by physical adsorption. Compared with the preparation of adsorbents from waste biological materials such as corn straw, peanut husk and rice husk, the preparation of activated carbon from walnut green peel is simpler and cheaper, and the removal effect of zinc ions is better. This study provides a new idea for the resource utilization of walnut green peel and the removal of zinc ions from wastewater.