Membrane process and adsorption on pine nut shell for removal of dye from synthetic wastewater

ABSTRACT

Purification methods such as membrane technology and adsorption have been studied for the purification of textile effluents. This article aimed to evaluate the membrane separation process and adsorption on pine nut shell, separately and sequentially, for reactive dye blue 5G removal from a synthetic effluent. The membrane separation process was carried out in a front filtration module using polymeric membranes. The maximum dye retention was 35.9% using a regenerated cellulose membrane, with agitation and a pressure of 0.5 bar. The permeate flux was fully restored after cleaning the membrane. In the adsorption using pine nut shell, the best results were at pH 2, 50°C, and 50 ppm, with 85% dye removal. The Freundlich isotherm showed the best fit to the data, as did the pseudo-second-order kinetic model. The thermodynamic parameters indicated that the adsorption is of the physical type, with the process being endothermic and spontaneous. In the combined process, the permeate from the membrane separation process was subjected to adsorption on pine nut shell, achieving a removal rate of 98.7 for the initial concentration of 50 ppm. Therefore, this work shows the potential of pine nut shell as an adsorbent, not only to purify textile effluents but also to add value to a waste product, indicating that the combination of membrane technology and adsorption on pine nut shell could be an alternative for the treatment of textile effluents containing the reactive dye 5G blue.

GRAPHICAL ABSTRACT

KEYWORDS:

• Membrane separation process
• adsorption
• combined process
• pine nut shell
• reactive dye blue 5G

Acknowledgements

This study was carried out with the support of Coordination for the Improvement of Higher Education Personnel (CAPES). The authors thank Federal University of Technology of Paraná and Multi-User Research Support Laboratory of Apucarana Campus (LAMAP – AP) for assisting in the development of this research.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All data generated and analysed during this study are included in this published article.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.