The Influence of biochars with relatively high ash contents on the fate of α-endosulfan and β-endosulfan with original biochars derive from three feedstocks (canna indical,acorus calamus, and phragmites autralias )at heat treatment temperature 550°C was evaluated. The pores of biochars were mainly mesoporous, and the ash occupied about15.86~27.29%, whose main composition were probably calcium carbonate. The nonlinear adsorption constant of biochars to endosulfan was from 0.63 to 0.80, which was a bit higher than that of deashed biochars (0.63~0.80). Besides, after deashed, the affinity between biochars andβ-endosulfan orα-endosulfan weakened and the adsorption capacity was limited (logKF ranged from 6744 to 11111mg/kg). In addition, the value of (O+N)/C decreased, the proportion of surface –C and bulk –C increased, indicating that deashing could reduce the polarity of carbon surface, increased the hydrophobicity, and expose more organic matter on surface, which would enhance the hydrophobicity of endosulfan. After adding to supernatant, the adsorption of endosulfan by deashed biochars dramatically improved, it also proved that the soluble substance in the supernatant were much likely enhance the adsorption effect between deashed biochars and endosulfan.%将美人蕉、菖蒲和芦苇等挺水植物通过限氧高温热解(500℃)制备生物炭,探究灰分对生物炭吸附硫丹的影响.研究表明:挺水植物生物炭表面孔隙发育成熟,以介孔为主,灰分含量较高(15.86%~27.29%),主要成分可能为碳酸钙.生物炭对硫丹的非线性吸附常数介于0.63~0.80之间,较去灰生物炭大(0.61~0.72).去灰后,生物炭对β-硫丹和α-硫丹的吸附能力降低(logKF在6744~11111mg/kg之间).但各生物炭比表面积增大(20.55~58.13m2/g),(O+N)/C值变小,炭表面极性降低,疏水性增强;且表层碳元素与主体碳占比增加,炭表面暴露出更多的有机质,增强对硫丹的疏水作用.加入上清液后,去灰后美人蕉、菖蒲和芦苇生物炭对硫丹的吸附变化显著,其上清液中的溶解性物质增强了去灰生物炭对硫丹的吸附作用.
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