Augmented dye eradication from wastewater using alkali-aided, reinforced waste acacia (Acacia auriculiformis) leaves

Abstract

The present investigation demonstrates the augmented dye scavenging from wastewater using alkali-mutated acacia (Acacia auriculiformis) leaves powder. The material was synthesized by mild chemical activation by using 0.1 M sodium hydroxide as an activator under room temperature stirring for 3h and isolated as a dark brown powder. The material was characterized using FTIR, FESEM, XRD, and pH_zpc; and tested successfully with crystal violet and methylene blue. While FTIR confirms the presence of polyphenolic and polysaccharide moieties, FESEM reveals unprecedented circular hollow pipe-like channels decorated in a highly ordered fashion, facing pores for optimum dye uptake. The adsorption is tunable with working pH, and the maximum adsorption capacities are 67.25 and 78.55 mg g⁻¹ for CV and MB. Both adsorption process follows Langmuir isotherm (R² = 0.994) and pseudo-2nd-order kinetics (R² = 0.999). Thermodynamic analysis verifies a spontaneous process with an endothermic interaction beside an elevated degree of randomness. About 80% of the spent material could be regenerated using 1:1 methanol/water. Analysis of industrial effluent suggests 37% removal per cycle, with an operating ceiling of 95%. To wind up, due to huge availability, porous nature, and superior adsorption capacity over other phytosorbents, NaOH-activated acacia leaves could be considered as techno-economic and potential scavengers for sustainable water treatment.

NOVELTY STATEMENT

Lignocellulosic waste plant litters have enormous potential for biosorption of heavy metals and dyes for their economic viability and environment-friendly nature. The present investigation highlights the promising cationic dye scavenging ability of alkali-treated waste acacia (A. auriculiformis) leaves from simulated and industrial wastewater. With adsorption capacities of 67.25 and 78.55 mg g⁻¹ for crystal violet and methylene blue respectively, the protocol shows promise in colored water treatment. Easy preparation, classy removal efficiency, and recyclability offer the key advantage with a techno-economic impact.

GRAPHICAL ABSTRACT

Keywords:

• Acacia leaves
• methylene blue
• crystal violet

Disclosure statement

The authors declare that they do not have any potential conflict of interest.

Additional information

Funding

PPS, MAQ, and SD thank the Central University of Jharkhand for providing fellowship.