Development, characterization and evaluation of composite adsorbent for the adsorption of crystal violet from aqueous solution: Isotherm, kinetics, and thermodynamic studies

Abstract The purpose of this work focuses on the production and investigations of a new composite material as alternative low-cost adsorbent for the removal of crystal violet (CV) dye from waste solution. The production method was performed by in-situ thermal activation technology via extrusion process of polymer wastes containing tire rubber (50 wt%) and polyurethane foam (50 wt%) using single-screw extruder under processing temperature of 180 °C and shearing rate 100 rpm. The physico-chemical properties of the materials obtained were examined such as bulk density, zero surface charge (pHpzc), Brunauer-Emmett-Teller (BET) surface area, as well as samples tested by infrared absorption spectroscopy (FT-IR), scanning electron microscopy (SEM). X-ray fluorescence spectroscopy (WD-XRF). Thermogravimetric analysis (TGA). These techniques were additionally applied to the full characteristics of the composite materials obtained. The impacts of solution pH (3.0–9.0), adsorbent dosage (0.1–1.0 g) and initial adsorbate concentration (in range 10 –90 mg/l) on adsorption capacity of the investigated adsorbent were studied. From our investigation we found that adsorption equilibrium was achieved within 200 min. The maximum monolayer adsorption capacity (qmax) for our composite adsorbent were obtained from the Langmuir equation and equaled 20.92 mg/g. Mathematical analysis has shown that the pseudo second kinetic model of the order describes the kinetics of the adsorption process well.