Removal of Reactive Black 5 (RB5) dye from Industrial Wastewater after Solid Phase Extraction with Zn-Al Layered Double Hydroxide as a Nano-Sorbent

Reactive dyes, any of a class of highly colored organic substances, primarily used for tinting textiles that attach themselves to their substrates by a chemical reaction that forms a covalent bond between the molecules of dye. Reactive dyes very toxic because of their low removal rate, thus finding a suitable solution to remove of this dyes with high efficiency seems to be essential. This dye solutions and an industrial textile wastewater were both treated by using Zn-Al LDH nano-particles. The Synthesized Zn-Al LDH was successfully applied as a solid-phase extraction nano-sorbent for the separation and pre-concentration of trace levels of RB5 from Textile wastewater samples [2]. 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 extraction efficiency of the analytes were investigated. The results showed that RB5 could be retained on the Zn-Al (NO3–) LDH at pH 7.0 and stripped by 3 mL of 0.3 mol L−1 NaOH [2].