Effects of biochar pyrolysis temperature on its characteristics and heavy metal adsorption

摘要

Pyrolysis temperature is one of the most important factors that affect the properties of biochar. Considering the environment pollution caused by heavy metal, Cornstalk-based Biochars (CB) are produced at a temperature range of 250～450°C and their characteristics on the adsorption of Cr(VI) were studied. The results showed that the best corn stalk pyrolysis temperature was 250°C. The adsorption of Cr(VI) agreed better with Langmuir model. In terms of adsorption kinetic, adsorption of Cr(VI) followed pseudo second order kinetic model. The substantial acidic functional groups on CB surface played a crucial role on the adsorption of Cr(VI). The characteristics of Cr(VI) adsorption was closely related to the pyrolysis temperature.