Capability of potato peel powder (PPP) for the adsorption of hazardous anionic Congo dye

Abstract

Congo red is a toxic anionic dye that is found in large amounts in textile industry effluents. Potato (Solanum tuberosum (STP) peel powder is inexpensive and readily accessible; it was utilized in this research to remove Congo red dye from an aqueous solution. The adsorbent was characterized by Fourier-Transform infrared and scanning electron microscopy techniques. For adsorption of Congo red dye on Solanum tuberosum peels the optimum conditions were an adsorbent dose of 0.6 g, contact time of 90 minutes, solution pH of 3, with adsorbates initial concentration 30 ppm and temperature are 50 °C, respectively. According to isothermal investigations, the sorption data was best fit with Freundlich and D–R isotherm. The kinetics of the process was found best to follow the pseudo-second order with (R² = 1) and $Q_{\mathrm{e}}\left(\mathit{\text{cal}}\right)$= 9.97 mg/g, which is close to the $Q_{\mathrm{e}}(\mathit{\text{exp}}$) = 9.96 mg/g. The plot of these two models demonstrated that physisorption and chemical adsorption were both possible. The fact that $\Delta$G and $\Delta$H are negative implies that the adsorption was spontaneous and exothermic. The findings of the desorption investigation revealed that 78% of the adsorbent had been regenerated and was ready for more adsorption studies. The procedure of applicability with tap water was investigated, and the results revealed that 72% of the Congo red dye was adsorbed under optimized conditions. Potato peel powder might be used as biosorbent for the treatment of effluents from dying and textile industries due to the high capability of Congo red dye.

HIGHLIGHTS

1. Adsorptive removal of Congo red by using potato peels powder was carried out.

2. The OH⁻ & COO⁻ groups on the PPP surface provided excellent binding with Congo red molecules.

3. The equilibrium attained in 90 minute at pH 3.0.

4. Kinetics, isotherm models, and thermodynamics were evaluated.

5. Desorption study resulted in 78% regeneration of potato peels powder and Congo red dye.

Graphical Abstract

Keywords:

• Adsorption
• potato peels powder
• Congo red
• desorption

Authors’ contributions

All Authors contribute equally to the manuscript.

Disclosure statement

Authors state no competing financial concerns to influence the work described in this research.

Funding

No funding was received for conducting this study.

Data transparency

Authors will ensure data transparency.

Data availability statement

All data generated or analyzed during this study are included in this article and accompanying supplementary file.