Abstract:In order to investigate effect of aging on surface properties of biochar and soil adsorption behavior of Cu(Ⅱ) with biochar, simulating aging of rice hull biochar prepared under two different temperatures was conducted in soil environment. Surface properties of rice husk biochars before and after aging were detected by elemental analyzer, diffuse reflection Fourier transform infrared spectroscopy (DRIFTS), and X-ray photoelectron spectroscopy (XPS). Meanwhile, another fresh biochar was added into soil at 3% and 5% by weight and incubation for 240 days, then the batch sorption experiment were carried out to determine Cu(Ⅱ) adsorption ability on biochars after aging and soil with aged biochars. The results show that oxygen contents rise while carbon contents drop in two kinds of biochars after 240 days aging, oxygen-containing functional groups, such as carboxyl, carbonyl, aliphatic hydroxyl, rise in two kinds of aged biochars and induce increasing of polarity of biochar. The maximum adsorption capacity of Cu(Ⅱ) on aged biochar is improved. Aging effect influences surface properties of biochar and facilitates soil adsorption on Cu(Ⅱ). Cu(Ⅱ) immobilization by soil with biochar has long-term stability.