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 pHzpc; 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 11 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.

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.