Removal of Azo Dyes from Water on a Large Scale Using a Low-Cost and Eco-Friendly Adsorbent

Abstract

The use of natural materials as adsorbents and the environmentally friendly removal of pollutants and azo dyes from water are important topics today. The goal of this research work was to assess the utility of Luffa cylindrica (L. cylindrica) as a natural and non-conventional adsorbent for azo dyes in water on a large scale (2 L). An azo dye (AD) at a concentration of 0.250 g/L was removed from the solution at a rate of 63.07% using 10.0 g/L doses of L. cylindrica, and the maximum adsorption capacity of L. cylindrica was 25.25 mg/g. L. cylindrica desorbed 95.8% of the AD in 0.1 M NaOH. Thermodynamically, the adsorption occurs through pseudo-second-order kinetics and the behaviors adjust better to the Langmuir isotherm. The analysis of variance (p-value < 0.05) shows that the contact time and the concentration of AD significantly influence the adsorption capacity and removal of AD. Few studies have examined the environmentally friendly removal of azo dyes from water using a natural non-conventional adsorbent.