Using Composite Chitosan-Graphene Oxide to Eliminate Reactive Blue 19 From Water Solutions: The Study of Adsorption Kinetics and Reaction Thermodynamics Publisher



Mohamadi MB^{1, 2, 3} ; Ejazi H^{1, 3} ; Azadbakht F⁴ Show Affiliations
Source: Desalination and Water Treatment Published:2019

Abstract

Textile wastewater constitutes a major environmental pollutant. Therefore, eliminating dye from textile wastewater is a main challenge for industrial wastewater treatment plants. Reactive blue 19, which is a common dye used in textile, is resistant to degradation, with stakeholders facing many difficulties in its elimination from water solutions. The current study aimed to examine the effect of composite chitosan-graphene oxide on eliminating reactive blue 19 from water solutions. The study also investigated the kinetics of the related reactions. This empirical study was conducted in a laboratory setting. Graphene oxide was synthesized from graphite powder using modified Hummer’s method. It was then duped by chitosan powder and the produced composite synthesized chitosan-graphene oxide was utilized to eliminate reactive blue 19 from water solutions. The effects of initial dye concentration (20, 40, 50, and 60 mg/l), nanocomposite dose (0.1, 0.3, 0.5, 0.7, 1, and 1.5 g/l), pH (4, 7, and 9), and exposure time (10, 20, 30, 40, 60, 90, and 120 min) were studied. The empirical data of adsorption equilibrium were compared with Langmuir adsorption isotherm. The percentages of eliminated dye were analyzed using Perzi. The findings showed that 99% of reactive blue 19 is eliminated from water solutions in optimal conditions (pH = 4, exposure time = 60 min, adsorption dose = 1 g/l, and dye concentration 20 mg/l). It was also discovered that the elimination pattern followed Langmuir isotherm and second-order kinetic model. The results of the present study showed that with the rise of contact time and absorbent dosage and the decline of reactive blue 19 concentrations, removal efficiency tends to increase. pH = 4, time = 60 min, absorbent dose = 1 g/l and concentration 20 mg/l were obtained as optimum conditions. Under optimum condition (pH = 4, time = 60 min, absorbent dose = 1 g/l and concentration 20 mg/l) the highest efficiency of in reactive blue 19 removal is 99%. The adsorption isotherm showed that absorption process correlates well with Langmuir adsorption isotherm (R2 > 0.98). Reaction kinetics complies with Pseudo-second order model with correlation coefficient of (R2 = 0.92). The results showed that synthesized composite chitosan-graphene oxide has the capability of effective elimination of reactive blue 19 from water solutions. Thus, it can be exploited as an effective and efficient adsorbent to treat water solutions and eliminate dye. © 2019 Desalination Publications. All rights reserved.