Zinc-aluminum layered double hydroxide as a nano-sorbent for removal of Reactive Yellow 84 dye from textile wastewater effluents

摘要

In this research, the zinc-aluminum layered double hydroxide (Zn-Al LDH) was synthesized and structurally and morphologically characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and N_2 adsorption-desorption techniques. The obtained nano-structured inorganic material was employed as an innovative nano-sorbent for separation of Reactive Yellow 84 (RY84) dye from aqueous solutions, which can be spectrophotometrically monitored at λ = 359 nm. The effect of several parameters such as type of interlayer anion in Zn-Al LDH structure, pH, sample flow rate, elution conditions, amount of nano-sorbent, sample volume and co-existing ions on the retention efficiency was investigated and optimized. The results showed that trace amounts of the RY84 could be retained using a column packed with 300 mg of the Zn-Al(NO_3 ~-) LDH at pH 8 and stripped by 2.5 mL of 3.0 mol L~(-1) NaOH. Under the optimum experimental conditions, the limit of detection and the relative standard deviation were 0.04 μg mL~(-1) and 1.8 %, respectively. The calibration graph using the presented solid phase extraction system was linear in the range of 0.15-1.5 μg mL~(-1) with a correlation coefficient of 0.9982. The method was successfully applied to removal of RY84 from several textile wastewater effluents.