Last modified: 2018-07-24
Abstract
In this study, MgAlFe-CO3 layered double hydroxide (LDH), with a Mg to (Al+Fe) molar ratio of 2 and Al to Fe molar ratio of 1:1, was successfully synthesized by coprecipitation method and its calcined product (MgAlFe-C) was obtained. The MgAlFe-CO3 and the MgAlFe-C samples, were characterized by FTIR, XRD, TGA and BET. Batch sorption studies were conducted to investigate adsorption of Diclofenac (DIC) and Ibuprofen (IBU) from water onto both adsorbents [1,2]. The results show that MgAlFe-C can be used as an effective adsorbent and its sorption capacity is higher than that of MgAlFe-CO3.The effects of various physicochemical parameters such as pH, contact time, effect of anions competitions and initial IBU/DIC concentration on the adsorption of IBU/DIC onto MgAlFe-C were investigated. Also, the regeneration study was done.
The results show that adsorption processes can be well described by the pseudo-second-order kinetic model. The adsorption data are fitted well with the Langmuir isotherm equation. The maximum adsorption capacity is 484 mg/g for DIC and 129 mg/g for IBU. The thermodynamic parameters were calculated. The negative ΔG0 and ΔH0 indicate that the adsorption processes are spontaneous and exothermic in nature. Coexisting ions such as CO, Cl could compete with IBU/DIC anions. The adsorption of IBU/DIC on the adsorbent can be mainly attributed to the memory effect process.
Regeneration study proves that calcined MgAlFe-C can potential material for the decontamination of pharmaceuticals micropollutants in wastewater.