Effect of biochars on adsorption of Cu(II), Pb(II) and Cd(II).pdf

Environ Sci Pollut Res (2013) 20:8491–8501 DOI 10.1007/s11356-013-1769-8 RESEARCH ARTICLE Effect of biochars on adsorption of Cu(II), Pb(II) and Cd(II) by three variable charge soils from southern China Ren-kou Xu An-zhen Zhao Received: 3 January 2013 /Accepted: 24 April 2013 /Published online: 7 May 2013 # Springer-Verlag Berlin Heidelberg 2013 Abstract The purpose of this study is to compare the relative non-electrostatic mechanisms, and the relative contribution of contribution of different mechanisms to the enhanced the two mechanisms varied with metals and biochars. adsorption of Cu(II), Pb(II) and Cd(II) by variable charge soils due to incorporation of biochars derived from crop straws. Keywords Crop straw biochar . Electrostatic adsorption . The biochars were prepared from the straws of canola and Heavy metals . Specific adsorption . Variable charge soil peanut using an oxygen-limited pyrolysis method at 350 °C. The effect of biochars on adsorption and desorption of Cu(II), Pb(II) and Cd(II) by and from three variable charge soils from Introduction southern China was investigated with batch experiments. Based on the desorption of pre-adsorbed heavy metals, the Adsorption reactions of heavy metals are important factors electrostatic and non-electrostatic adsorptions were separated. controlling the mobility of these metals in soils. Low cation EDTA was used to replace the heavy metals complexed with exchange capacity (CEC) and pH create conditions conducive biochars and to evaluate the complexing ability of the biochars to increasing mobility of heavy metal cations in variable charge with the metals. The incorporation of biochars increased the soils, which are distributed with large areas in tropical and adsorption of Cu(II), Pb(II) and Cd(II) by the soil; peanut subtropical