Objective To explore the approach of recycling of agricultural waste renewable resources.

Methods The copper ions by biochar from Korla pear branches was used as adsorbent, and the characteristics of copper adsorption by biochar were investigated by scanning electron microscopy, FTIR infrared and XRD, and the adsorption effects of adsorption time, initial concentration of solution, adsorption temperature, adsorbent dosage, initial pH of solution and other factors on the adsorption of copper ions of biochar in pear branches were explored. Afterwards, the adsorption kinetics and isothermal characteristics of adsorption were discussed.

Results Under the conditions of temperature of 50 °C and pH of 3～6, the adsorption equilibrium of copper ions could be reached within 240 min, and the optimal dosage of biochar was 1.6 g/L, the initial concentration of copper ions was 100 mg/L and the maximum adsorption capacity were 32.11 mg/g, respectively, the adsorption process conforms to the second-order kinetic equation, and the isothermal adsorption curve conformed to the Langmuir model, indicating that the adsorption process is mainly similar to the chemical adsorption of the monolayer.