Synthesis and application of p-tert-butylcalix[8]arene immobilized material for the removal of azo dyes

• Published in: Journal of hazardous materials 2011-02, Vol.186 (1), p.651-658
• Main Authors: Kamboh, Muhammad Afzal, Solangi, Imam Bakhsh, Sherazi, S.T.H., Memon, Shahabuddin
• Format: Article
• Language: English
• Subjects: Adsorption; Applied sciences; Azo Compounds - isolation & purification; Azo dye; Azo dyes; Batch-wise sorption; Calixarene; Calixarenes - chemical synthesis; Calixarenes - chemistry; Chemical engineering; Coloring Agents - isolation & purification; drinking water; Drinking water and swimming-pool water. Desalination; effluents; electrolytes; Exact sciences and technology; Fourier transform infrared spectroscopy; General purification processes; Hydrogen-Ion Concentration; Immobilization; Isotherms; Materials selection; Microscopy, Electron, Scanning; Pollution; salinity; scanning electron microscopes; Scanning electron microscopy; Silica; Silicon dioxide; Sodium Chloride - chemistry; Sorbents; Sorption; Sorption isotherms; Spectrophotometry, Ultraviolet; Spectroscopy, Fourier Transform Infrared; Thermogravimetry; Wastewaters; Water treatment and pollution
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2010.11.058

The sorption of selected azo dyes is highly pH dependent and newly immobilized material 4 is potentially more effective sorbent as compared to pure silica (1) as well as p-tert-butylcalix[8]arene (3). [Display omitted] ▶ Sorption behavior investigation of p-tert-butyl-calix[8]arene immobilized material4. ▶ Azo dyes (i.e. RB-5 and RR-45) were used as sorbate. ▶ Optimization of different parameters to evaluate sorption performance of material 4. ▶ Sorption efficiency of resin 4 for RB-5 and RR-45 azo dyes is highly pH dependent. ▶ The sorption data was evaluated by sorption isotherms. The present study describes synthesis of a new resin through immobilization of p-tert-butylcalix[8]arene onto silica and its application for the removal of azo dyes from aqueous media as well as from textile effluents. The newly synthesized material 4 is characterized by FT-IR spectroscopy, scanning electron microscope (SEM) and thermogravimetric analysis (TGA). Reactive Black-5 (RB-5) and Reactive Red-45 (RR-45) azo dyes were used as sorbate. Batch wise sorption experiments were conducted to optimize various experimental parameters such as the effect of sorbent dosage, electrolyte, pH, dye concentration, and contact time. The optimized pH for the effective removal of RB-5 and RR-45 dyes was 9 and 3, respectively. The increase in material 4 dosage increased the percent sorption. Both Langmuir and Freundlich isotherm models were applied to experimental data and Langmuir isotherm model found to be best fit. The results revealed that material 4 was potentially more effective sorbent for the sorption of selected azo dyes as compared to pure silica and p-tert-butylcalix[8]arene. The field studies also supported the effectiveness of material 4, which could be useful for the removal of both the dyes and also for the normalization of pH, TDS, conductivity and salinity near to the drinking water.