Membrane capsules with hierarchical Mg(OH)2 nanostructures as novel adsorbents for dyeing wastewater treatment in carpet industries

•Membrane capsules were prepared as novel adsorbent via electrospraying technique.•Hierarchical Mg(OH)2 nanostructures were utilized for improving dye adsorptivity.•Textile dyeing wastewater in Yaldaye Kavir Co. (Kashan) was treated with 90% removal.•Best membrane capsule was chosen with Type 2-B of nanostructures in mixed solutions.

Dye bearing wastewater poses a serious threat to the aquatic environment due to its appearance and toxicity. The removal of color from wastewater is a major problem for developing countries due to lack of efficiency of the conventional methods and high cost involved for the treatment process. In this research, a novel kind of adsorbents was proposed with high amount of basic dye removal. These adsorbents were named membrane capsules and were utilized for treating industrial textile wastewater in Yaldaye Kavir Co. (Kashan). The membrane capsules were prepared via a cost-efficient technique i.e. electrospraying that their average diameter was 1.1 mm. It was taken advantage of hierarchical Mg(OH)2 nanostructures as excellent adsorptive filler. These nanostructures were classified in two main morphologies. In the first morphology, the hierarchical nanostructures were cylindrically formed, while the second one took shape like a flower. Mg mapping of these microspherical adsorbents confirmed a perfect dispersion of these nanostructures. The flower-like Mg(OH)2 nanostructures with 45 nm nanoparticles on their surface showed the best performance for all industrial basic dyes (>90%). The thermodynamic isotherm of adsorption for this optimum membrane capsule was Langmuir type. Also, the adsorptive rate of Basacryl Red GL conformed to second-order kinetical model.

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