The Effects of Wheat-Straw Derived Biochar on Adsorption of Atrazine in Soil

The biochar (BC) has been used as the adsorbent of various organic compound and inorganic metal because of simple preparation method, rich resource and efficient adsorption capacity. We prepared biochar from oxygen - limited pyrolysis of wheat straw. Adsorption of Atrazine, a kind of herbicide, in soil treated with the prepared different particle size wheat straw biochar (WSBC). Results show that the equilibrium datum of atrazine in WSBC were well described by the Langmuir than the Freundlich isotherm model, R-2=0.99. The adsorption kinetics demonstrated that the adsorption process of atrazine on the WSBC follows closely a pseudo-second-order kinetic model. The calculated qe values agree well with the experimental values and the correlation coefficient values are 1.00 for all particles sizes. The optimum WSBC application to soil can affect the persistence and efficacy of atrazine. The adsorption of atrazine in the soils increased with the increasing portion of WSBC compared with original soil. The removal rate of atrazine in the soil added with WSBC 0%, 1%, 2%, 5% were 22.38%, 67.28%, 88.91% and 98.44% respectively. When the environment of solution was neutrallty condition, it obtained effective sorption. Furthermore, BC could provide a means of effective contaminant sequestration in agricultural soils to prevent contamination of the wider environment.