Removal of methylene blue from aqueous solution using modified Polystyrene-Calixarene (PS-C) composite

Abstract

Synthetic dyes are chemical substances that widely used to impart colors in many materials. Without appropriate treatment, these chemicals easily to contaminate water body, create environmental problem and generate acute effects to human health. Although many physical, chemical and biological methods have been introduced however, these pretreatment techniques were always expensive, extremely energy-consuming, less environmentally efficient and produce toxic precipitate. Alternatively, absorption technique using modified waste material is currently used to solve this problem due to its characteristics such as efficient, cheap and easy. Therefore, this research adsorbent made of modified waste polystyrene incorporated with C-3,4,5-trimethoxyphenylcalix[4]-2-methyl resorcinarene (PS-C) was prepared. The synthesized adsorbent was characterized by Fourier Transform Infrared (FTIR) spectroscopy, Thermogravimetric analysis (TGA), Gel Permeation Chromatography (GPC) and Ultraviolet–Visible Spectroscopy (UV–VIS). The adsorbent adsorption behavior was evaluated against simulated organic dye, methylene blue (MB) solution. The incorporation of calixarene into waste polystyrene structure has increased the dye absorbency. The adsorption of 6 samples of MB with different concentrations onto PS-C fits the second-order kinetic model with a regression value, R2 of 0.9998. The equilibrium adsorption data of MB onto PS-C were interpreted using Langmuir and Freundlich models. It is better represented by the latter equation. The PS-C absorbent shows an excellent percentage of dye adsorption up to 75%. This study proved that the PS-C has a great potential to be used as an effective adsorbent for wastewater treatment.