The adsorption of the dyes Basic Red 46 (BR46) and Reactive Yellow 176 (RY176) from aqueous solution onto natural and modified zeolites has been investigated. The surfactants cetyltrimethylammonium bromide (CTAB) and hexadecyltrimethylammonium bromide (HDTMA) were used to modify the zeolite surface, and Fourier transform infrared spectroscopy (FTIR) spectral analysis was used to confirm the surface modification. The effects of initial dye concentration, contact time, pH, temperature, ionic strength, and surfactant type on adsorption were studied in a batch system. BR46 adsorption onto natural zeolite increased to minor a extent with increasing pH, whereas pH did not significantly affect RY176 adsorption. Adsorption capacities of dyes increased with contact time, initial concentration, and temperature for both BR46 and RY176. The increase in ionic strength caused a decrease in adsorption of BR46 and an increase in adsorption of RY176. Adsorption of BR46 on natural zeolite is more favorable than RY176 on the CTAB and HDTMA modified zeolites. The adsorption of basic and reactive dyes was spontaneous and endothermic as concluded from thermodynamic assays.

Polyester-glycidyl methacrylate (GMA)-based poly(high internal phase emulsion)s (polyHIPEs) with 85% internal phase were prepared by using unsaturated polyester resin (UPR), glycidyl metahacrylate and divinylbenzene (DVB) or styrene (St) with triethanolamine (TEA) as an emulsifier in the presence of a porogen. Porous monoliths were obtained by a removal of internal phase after curing of dispersed phase at 80°C. Morphologies and surface properties of obtained porous monoliths were investigated by scanning electron microscopy (SEM) and Brunauner-Emmet-Teller (BET) molecular adsorption methods. Amine functionalization of epoxy groups of polyHIPEs was achieved by reactions with several amines such as 1,4-ethylenediamine (EDA), 1,6-hexamethylenediamine (HMDA), 4-aminosalicylic acid (ASA), 2-aminothiazole (ATAL), 4-aminobenzothiazole (ABTAL) and 2-phenylimidazole (PIAL), respectively. The functionalized polyHIPEs were characterized by elemental analysis and the best result was obtained with the 1,4-ethylenediamine (EDA) ligand. The adsorption capacities of the modified monoliths for Ag(I), Cu(II) and Cr(III) were determined under non-competitive conditions at room temperature. The results showed that the maximum adsorption capacities of the modified monoliths decrease in order of Ag(I) > Cu(II) > Cr(III) and polyHIPE with 2-phenylimidazole (PIAL) groups is the most effective adsorbent for heavy metal ions.

The combined process of coagulation and adsorption was studied for the treatment of reactive dye wastewaters. Ferric chloride and organozeolite modified with CTAB were chosen as the coagulant and adsorbent, respectively. Reactive dyes, namely, Reactive Blue 4 (RB4) and Reactive Yellow (RY), were used as representatives of anthraquinone and azo textile dyes. A series of jar-test and batch experiments were conducted to determine the optimum conditions. According to individual dye removal efficiencies, coagulation is the main treatment process of the combined process, and RY has better performance than RB4. Coagulation followed by adsorption was found to be very effective for color removal with more than 99.50% and for COD removal with more than 97.25%.

In this study, covalent immobilization of the horseradish peroxidase (HRP) onto various polysulfone supports was investigated. For this purpose, different polysulfones were methacrylated with methacryloyl chloride, and then, nonwoven fabric samples were coated by using solutions of these methacrylated polysulfones. Finally, support materials were immersed into aquatic solution of HRP enzyme for covalent immobilization. Structural analysis of enzyme immobilization onto various polysulfones was confirmed with Fourier transform infrared spectroscopy, atomic force microscopy, and proton nuclear magnetic resonance spectroscopy. Decolorization of textile diazo (Acid Black 1) and anthraquinone (Reactive Blue 19) dyes was investigated by UV-visible spectrophotometer. Covalently immobilized enzyme has been used seven times in freshly prepared dye solutions through 63 days. Dye decolorization performance of the immobilized systems was observed that still remained high (70%) after reusing three times. Enzyme activities of immobilized systems were determined and compared to free enzyme activity at different conditions (pH, temperature, thermal stability, storage stability). Enzyme activities of immobilized systems and free enzyme were also investigated at the different temperatures and effects of temperature and thermal resistance for different incubation time at 50 °C. In addition, storage activity of free and immobilized enzymes was determined at 4 °C at different incubation days.