Removing Pb(II) by means of natural and acid-activated nanoporous clays

2nd International Conference on Engineering Sciences

Ghazizahedi, Z.^1 ; Hayati-Ashtiani, M.^1

Department of Chemical Engineering, Faculty of Engineering, University of Kashan, Kashan, Iran^1

关键词: Brunauer-emmett-teller surface areas;    Liquid to solid ratio;    Nano-structured;    Natural bentonite;    Removal capacity;    Solution concentration;    Sulfuric acid solution;    X ray fluorescence;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/433/1/012069/pdf
DOI  :  10.1088/1757-899X/433/1/012069

来源: IOP

【 摘 要 】

Heavy metals such as Pb(II) are harmful to both the environment and human health as they are both toxic and stable. Bentonite clays contain Montmorillonite, which is a nano-porous and nano-structured mineral that can act to remove metals. In these experiments, natural bentonite S1 was activated using sulfuric acid solutions under various conditions with a range of Liquid to Solid ratios (L/S), Temperatures (T), Times (t) and Concentrations (C). The activated samples S2 (L/S = 16 mL/g, T = 95 °C, t = 4 h, C = 5 M) and S3 (L/S = 16 mL/g, T = 95 °C, t = 6 h, C = 0.5 M) showed the highest and the lowest amounts of Pb(II) removal, respectively. The characterisation of natural and acid-activated bentonites in terms of Pb(II) separation applications were examined using Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), X-Ray fluorescence (XRF), Brunauer-Emmett-Teller (BET) surface area measurements, and Fourier Transform Infrared Spectroscopy (FTIR). Metal removal experiments were conducted using a suspension of 0.3 g suspended in 25 mL Pb(NO3)2 solution under fixed solution concentrations of 2,000 mg/L. The suspensions were thoroughly mixed for 24 hours at 250 rpm. The results showed the removal capacities of samples followed the order of S2 > S3 > S1, and suggested that the prevailing Pb(II) removal processes were adsorption and ion exchange.