LAUSR

The preparation of bentonite-zeolite (BZ) adsorbent using bentonite, aluminate, and rice husk was conducted. The adsorption experiment was performed for the removal of Cu2+ and Zn2+ from aqueous solution in single and binary systems. Results showed that gasification of rice husk could effectively improve the specific surface area and pore volume. The optimum pH for Cu2+ and Zn2+ adsorption on BZ was pH 5.0. The pseudo-first order kinetic and Langmuir isotherm model of BZ were the optimal model for Cu2+ and Zn2+. According to Langmuir isotherm model, the maximum adsorption capacity value (qm) was 16.39 and 12.72 mg·g-1 for Cu2+ and Zn2+, respectively. The adsorption affinity order of BZ in the binary solution was Cu2+ > Zn2+. NH4+-N concentration over 500 mg·L-1 significantly affected the adsorption capacity of BZ (P < 0.05). The adsorption capacity of BZ for Cu2+ and Zn2+ was higher than that artificial zeolite (AZ) and bentonite in SW.