Abstract：
To enhance the adsorption performance of municipal sludge biochar on Cd(II), modified sludge biochar was prepared by sodium hydroxide/magnesium chloride (NaOH/MgCl2) graded activation, and the Cd(II) adsorption performance on sludge biochar (BC), NaOH-activated sludge biochar (NBC) and NaOH/MgCl2 activated sludge biochar (NBC-Mg) was investigated. The results showed that NaOH/MgCl2 graded activation upgraded the surface structure and enhanced the graphitization of sludge biochar. The adsorption experiments indicated that the adsorption kinetic and adsorption isotherm for Cd(II) were in accordance with the pseudo second-order kinetic and Langmuir model. The adsorption capacity of NBC-Mg (143.49 mg/g) for Cd(II) was higher than that of BC (50.40 mg/g) and NBC (85.20 mg/g). The mechanism of Cd(II) adsorption included ion exchange, complexation, cation-π interaction, and mineral precipitation. After five regeneration, the removal efficiency of Cd(II) by NBC-Mg remained above 90%. This work indicated that sludge biochar prepared by multistage activation could be an effective material for Cd-containing wastewater treatment.
摘要：
为提高城市污泥生物炭对Cd(Ⅱ)的吸附性能,采用氢氧化钠/氯化镁(NaOH/MgCl2)分级活化法制备改性污泥生物炭,污泥生物炭(BC)对Cd(II)的吸附性能,研究了NaOH-活性污泥生物炭（NBC）和NaOH/MgCl2活性污泥生物炭（NBC-Mg）。结果表明，NaOH/MgCl2分级活化改善了污泥生物炭的表面结构，增强了污泥生物炭的石墨化。吸附实验表明，Cd(II)的吸附动力学和吸附等温线符合拟二级动力学和Langmuir模型。NBC-Mg(143.49mg/g)对Cd(II)的吸附量高于BC(50.40mg/g)和NBC(85.20mg/g)。Cd(Ⅱ)吸附机理包括离子交换,络合,阳离子-π相互作用，和矿物沉淀。经过五次再生，NBC-Mg对Cd(II)的去除效率保持在90%以上。这项工作表明，通过多级活化制备的污泥生物炭可以成为处理含Cd废水的有效材料。
