Optimized Dewaxed Honeycomb Powder as a Promising and Eco-Friendly Alternative for the Removal of Malachite Green through Fixed Bed Column

Abstract

A fixed-bed column study for the removal of malachite green (MG) from the aqueous phase was demonstrated using strategically dewaxed honeycomb powder (HCP). The removal efficiency was tested at several working parameters of the column, in particular, the column bed height, initial dye concentration, working pH, and the flow rate. Breakthrough curves have been plotted using the throughput volume versus concentration ratio for different parameters to identify the pathway of uptake. Thomas and bed depth service time (BDST) kinetic models have been applied to obtain the rate constants and the uptake capacity. The BDST model suggests an adsorption capacity of 196.28 mg L^–1. The column performance was seen to vary with solution pH and was found favourable at higher pH values. The adsorption rate decreases with increasing flow rate but increases with increasing concentration of the dye. Easy regeneration ensures multi-cycle operations. The mechanism of dye adsorption by HCP has been proposed as a blend of electrostatic attraction and weak forces. Henceforth, the use of HCP for the removal of MG in column mode may be extrapolated to serve as a promising agent in the treatment of dye-containing water and wastewater.