【摘要】 为探讨固液体系中限氧裂解法制备粟米秸秆生物炭对Pb²⁺的吸附特性与机理,通过静态批量试验研究了pH、初始离子浓度、吸附剂投加量、吸附时间对粟米秸秆炭吸附Pb²⁺特性的影响,并通过热力学分析其吸附作用机理。结果表明,粟米秸秆炭对Pb²⁺吸附在pH为5.5～6.0范围内效果最好,其吸附能力与温度和离子浓度正相关,与吸附剂投加量负相关。粟米秸秆炭对Pb²⁺吸附反应满足Lagergren准二级动力学模型,Langmuir模型拟合等温吸附过程结果较好。扫描电镜和傅里叶红外光谱对材料吸附前后分析表明,粟米秸秆在炭化和吸附Pb²⁺后的表面形态发生改变,羟基和羧基等表面活性基团在该吸附过程中起主要作用。更多还原

【Abstract】 In order to explore the adsorption characteristics and mechanism of Pb²⁺ on millet straw biochar prepared by limited oxygen pyrolysis in solid-liquid system, static batch experiments were performed to evaluate the effects of pH, initial concentration of Pb2 +,adsorbent concentration, contact time on Pb2 +adsorption. The mechanism of adsorption was analyzed based on thermodynamics. The results showed that the maximum removal rate appeared at pH 5.5～6.0, and adsorption quantity of millet straw was positively correlated with temperature and initial concentration of Pb²⁺ , and negatively correlated with adsorbent dosage.The experimental data fitted well with the Pseudo-second-order model. The adsorption equilibrium data and the adsorption process fitted well with Langmuir isotherms model.Scanning electron microscopy revealed that the surface morphologicalof millet straw changed after pyrolysis or absorption. The Fourier transform infrared spectroscopy（FTIR） spectra analysis showed that the possible functional groups responsible for Pb²⁺ binding were hydroxyl and carboxyl.更多还原