海藻生物炭对水溶液中甲基橙的吸附效果与机制

Effects and Mechanisms of Methyl Orange Adsorption from Aqueous Solutions by Algal Biochar

以褐藻为原料制备海藻生物炭吸附剂对其物化性质进行了表征,分析了影响甲基橙(MO)吸附的因素。结果表明,海藻生物炭优化热解温度是700℃,KOH为改性剂,浸渍比(改性剂与生物炭的质量比)为3:1,热解时间270 min,在此条件下制备的生物炭比表面积为340.1 m2/g,平均孔径2.698 nm,具有良好的MO去除效果。当MO的质量浓度为100 mg/L,添加量为20 mg,吸附时间270 min,MO的去除率为97.24%。吸附等温线数据拟合符合Langmuir模型,吸附动力学数据拟合符合准1级动力学模型,说明吸附以物理吸附为主、化学吸附为辅。因此,以褐藻生物质为原料制备的生物炭可作为吸附剂,并应用于水体中有机染料类污染物的治理。

Brown algae was used for algal biochar preparation, and the physical and chemical properties of algal biochar were analyzed, and the factors affecting the adsorption of methyl orange(MO) was analyzed. The results showed that, the optimized pyrolysis temperature of algal biochar was700 ℃, KOH was the modifier, the impregnation ratio(mass ratio of modifier to biochar) was 3:1, and the pyrolysis time was 270 min, the biochar prepared under these conditions had a specific surface area of 340.1 m2/g and an average pore diameter of 2.698 nm, which had a good MO removal effect. The removal rate of methyl orange was 97.24%, when the mass concentration of MO was 100 mg/L, the addition amount was 20 mg, and the adsorption time was 270 min. The fitting of adsorption isotherm data conformed to the Langmuir model, and the fitting of adsorption kinetics data conformed to the pseudo-first kinetic model, which indicated that the adsorption was mainly physical adsorption, and chemical adsorption was supplemented. Therefore, biochar prepared from brown algae biomass could be used as an adsorbent and applied to the treatment of organic dye pollutants in water bodies.