School of Civil Engineering, Anhui Jianzhu University, Hefei, 23061, People's Republic of China.
Anhui Province Intelligent Underground Exploration and Environmental Geotechnical Engineering Research Center, Anhui Jianzhu University, Hefei, 230601, Anhui, People's Republic of China.
Environ Sci Pollut Res Int. 2024 Apr;31(19):28379-28391. doi: 10.1007/s11356-024-32972-0. Epub 2024 Mar 27.
To enhance the adsorption performance of municipal sludge biochar on Cd(II), modified sludge biochar was prepared by sodium hydroxide/magnesium chloride (NaOH/MgCl) graded activation, and the Cd(II) adsorption performance on sludge biochar (BC), NaOH-activated sludge biochar (NBC) and NaOH/MgCl activated sludge biochar (NBC-Mg) was investigated. The results showed that NaOH/MgCl 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.
为了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/MgCl）分级活化的方法制备了改性污泥生物炭，并研究了污泥生物炭（BC）、氢氧化钠活化污泥生物炭（NBC）和氢氧化钠/氯化镁活化污泥生物炭（NBC-Mg）对 Cd(II)的吸附性能。结果表明，NaOH/MgCl 分级活化提高了污泥生物炭的表面结构，增强了其石墨化程度。吸附实验表明，Cd(II)的吸附动力学和吸附等温线符合准二级动力学和 Langmuir 模型。NBC-Mg（143.49 mg/g）对 Cd(II)的吸附容量高于 BC（50.40 mg/g）和 NBC（85.20 mg/g）。Cd(II)的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)的去除率仍保持在 90%以上。这项工作表明，多级活化制备的污泥生物炭可以作为一种有效的含镉废水处理材料。
