研究了水溶液中铬(Cr)(VI)和镍(Ni)(II)在日期坑(DP)上的吸附行为与初始浓度(5-100mg/L)的关系,接触时间(0-70分钟),吸附剂剂量(2-20g/L),pH(1-9),和温度(25-95[公式:参见正文]Cr(VI)和Ni(II)在45和55分钟后发生平衡,分别。Cr(VI)和Ni(II)的去除效率分别达到100%和95%,分别,在最佳条件下。傅里叶变换红外光谱(FTIR),扫描电子显微镜(SEM),进行Brunauer-Emmett-Teller(BET)分析以表征吸附剂。Langmuir,Freundlich,Tempkin,应用Dubinin-Radushkevich(D-R)模型来描述平衡等温线。自由能(ΔG)的值,焓(ΔH),熵(ΔS)为34.599kJ/mol,17.5736kJ/molK,和-51.58kJ/molK,分别,在pH3下,Cr(VI)和-25.283kJ/mol,-14.8525kJ/molK,和31.31kJ/molK,分别,在pH6的Ni(II)。分析了吸附动力学。伪一阶模型适用于R2=0.9977的Cr(VI),伪二阶模型适用于R2=0.999的Ni(II)。最大吸附容量为110.02mgCr(VI)/g和10.1mgNi(II)/g。基于最佳等温线,设计了单级间歇式吸附器,用于DP吸附Cr(VI)和Ni(II)。
The adsorption behavior of Chromium (Cr)(VI) and Nickel (Ni)(II) from aqueous solution onto date pits (DPs) was investigated as a function of initial concentration (5-100 mg/L), contact time (0-70 min), adsorbent dose (2-20 g/L), pH (1-9), and temperature (25-95[Formula: see text] Equilibrium took place after 45 and 55 min for Cr(VI) and Ni(II), respectively. The removal efficiency reached 100% and 95% for Cr(VI) and Ni(II), respectively, at optimal conditions. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) analyses were performed to characterize the adsorbent. The Langmuir, Freundlich, Tempkin, and Dubinin-Radushkevich (D-R) models were applied to describe the equilibrium isotherms. The values of the free energy (ΔG), enthalpy (ΔH), and entropy (ΔS) were 34.599 kJ/mol, 17.5736 kJ/mol K, and -51.58 kJ/mol K, respectively, at pH 3 for Cr(VI) and -25.283 kJ/mol, -14.8525 kJ/mol K, and 31.31 kJ/mol K, respectively, at pH 6 for Ni(II). Kinetics of the adsorption was analyzed. The pseudo-first-order was suitable for Cr(VI) at R2 = 0.9977, and the pseudo-second-order model was suitable for the Ni(II) at R2 = 0.999. The maximum adsorption capacities were 110.02 mg Cr(VI)/g and 10.1 mg Ni(II)/g. A single-stage batch adsorber was designed for the adsorption of Cr(VI) and Ni(II) by DP based on the optimum isotherm.