Suppression of Chlorantraniliprole Sorption on Biochar in Soil-Biochar Systems

The sorption behavior of chlorantraniliprole (CAP) by biochar and effect of soil extracts on sorptivity in soil-biochar systems were examined. The results showed that biochar amendment could enhance the sorption of CAP in soils. The values of K F increased significantly when the soils were amended with 0.5 % BC850, which were from 1.54 to 196.5. The indigenous sorptivity of biochar was suppressed after it was applied to the soils. The degree of biochar sorptivity attenuation in different soil-biochar systems varied with the properties of soil water soluble matters. Sorption of CAP by biochar from the five soil extracts was found to be lower than that from a CaCl2 solution. The calculated K d values at C w of 0.01 mg kg(-1) for biochar sorption of CAP from CaCl2 solution were 21.4-26.6 times of that from soil extracts. Aging of biochar in soil extract reduced CAP sorption by up to 85 %.