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以咖啡渣为原料,结合电子扫描显微镜、红外光谱分析仪和Zeta电位仪等研究吸附条件对吸附效果影响及吸附机理.结果表明:pH值为4、咖啡渣投加量为20g·L-1时,咖啡渣对Pb2+和Zn2+的吸附量最大,分别为5.49,12.38mg·g-1;吸附反应在4h后达到平衡,用拟二级动力学模型和Freundlich方程拟合效果较好;咖啡渣的电负性随pH值增加而增大,吸附Pb2+和Zn2+后表面变平整且出现白色颗粒;红外光谱图结果发现咖啡渣中参与吸附反应的基团主要有酰胺基、酯基、酮基.
The effects of adsorption conditions on the adsorption and the adsorption mechanism were studied by using coffee grounds as raw materials and scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and Zeta potentiometer. The results showed that pH value was 4 and dosage of coffee grounds was 20 g · L -1 , The adsorption capacity of coffee grounds to Pb2 + and Zn2 + was5.49,12.38mg · g-1, respectively. The adsorption reaction reached the equilibrium after4h, and the fitting effect was better with the pseudo-second-order kinetic model and Freundlich equation. The electronegativity increased with the increase of pH value. The surface of Pb2 + and Zn2 + adsorbed Pb2 + and Zn2 + became flat and white particles appeared. The results of IR showed that there were mainly amide group, ester group and keto group in the residue of coffee residue.