Treatment of gold ore cyanidation wastewater by adsorption onto a Hydrotalcite-type anionic clay as a novel adsorbent
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RESEARCH ARTICLE
Treatment of gold ore cyanidation wastewater by adsorption onto a Hydrotalcite-type anionic clay as a novel adsorbent Rasool Alaei 1 & Sepideh Javanshir 1
&
Ali Behnamfard 1
Received: 30 March 2019 / Accepted: 22 June 2020 # Springer Nature Switzerland AG 2020
Abstract The treatment of cyanide contaminated wastewater from a gold processing plant was performed by the synthesized nanostructured Layered Double Hydroxide (LDH) which has known as a Hydrotalcite-type anionic clay. LDH was synthesized by the coprecipitation process, characterized by X-ray fluorescence (XRF), X-ray powder diffraction (XRD), scanning electron microscope (SEM) Brunauer-Emmett-Teller (BET), Fourier-transform infrared spectroscopy (FTIR) and Wavelength Dispersive Xray analysis (WDX) and applied for removal of free cyanide from both synthetic solution and mining effluent. The maximum particle size of synthesized LDH was determined to be 4 nm based on the Scherrer’s equation. The maximum loading capacity of LDH, 60 mg/g, indicates that LDH is an interesting adsorbent for cyanide removal. The data modeling showed that the kinetic and equilibrium data best fitted by FPKM and RPIM, respectively, also, rate-controlling step in the adsorption process is intraparticle diffusion based on Weber–Morris plot, and the adsorption of CN− onto LDH is a two-step process. The thermodynamic studies confirm that the adsorption of free cyanide on Mg/Al LDH is a spontaneous and endothermic process. The energy of activation for adsorption of free cyanide on Mg/Al LDH was determined to be 6.14 kJ/mol, which is in the range physicochemical sorption. The mining wastewater treatment was performed by the synthesized LDH. The adsorption experiments showed that more than 90% of free cyanide was removed from the real solution during a short period of contact time, which confirms the ability of LDH for the treatment of industrial cyanide contaminated wastewater.
Keywords Cyanide adsorption . Mining wastewater . Nanostructured layered double hydroxide . Kinetic data modeling . Thermodynamic studies Nomenclature EPA Environmental Protection Agency. LDH Layered Double Hydroxide. XRD X-Ray Diffraction. XRF X-Ray Fluorescence. SEM Scanning Electron Microscopy. WDX Wave length dispersive X-ray. FTIR Fourier transform infrared. BET Brunauer-Emmett-Teller. BJH Barrett–Joyner– Halenda. MPSD Marquardt’s percent standard deviation. ARE Average Relative Error. R2 Correlation coefficient.
LAIM FRIM TEIM RPIM KCIM ELKM FPKM PFOKM PSOKM WMIDM qe qt D K
* Sepideh Javanshir [email protected]
λ θ β C0
1
Mining engineering Department, Faculty of Engineering, University of Birjand, Birjand, Iran
Langmuir Isotherm Model. Freundlich Isotherm Model. Temkin Isotherm Model. Redlich–Peterson Isotherm Model. Koble–Corrigan Isotherm Model. Elovich Kinetic Model. Fractional Power Kinetic Model. Pseudo-First Order Kinetic Model. Pseudo-Second Order Kinetic Model. Weber and Morris Intaparticle Diffusion Model. The adsorbed cyanide after equilibrium (mg/g). The adsorbed
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