removal of organic dye compounds in water and wastewater samples based on covalent organic frameworks -titanium dioxide before analysis by uv-vis spectroscopy

A simple and rapid microwave-assisted combustion method was developed to synthesize homogenous carbon nanostructures (hcns). this research presents a new and novel nanocomposite structures for removal of methylene red (2-(4- dimethylaminophenylazo) benzoic acid), methylene orange (4-[4-(dimethylamino) phenylazo]benzenesulfonic acid sodium salt) and methylene blue (3,7-bis(dimethylamino)phenazathionium chloride)with semi degradation-adsorption solid phase extraction (sda-spe) procedure before determination by uv-vis spectroscopy. a covalent organic frameworks (cofs) with high purity were synthesized and characterized by x-ray diffraction (xrd) and scanning electron microscopy (sem). the results indicated that the self-assembled carbon nanostructures (cofs) synthesized with the cost-effective method which was used as a novel adsorbent for adsorption of dyes after semi-degradation of methylene red, orange and blue (1-5 mg l-1) as an organic dye by titanium dioxide (tio2) nanoparticales in presence of uv radiation. based on results, the cofs/tio2 has good agreement with the langmuir adsorption isotherm model with favorite coefficient of determination (r2= 0.9989). the recovery of dye removal based on semi-degradation/adsorption of cofs/tio2 and adsorption of cofs were obtained 98.7% and 48.3%, respectively (rsd less than 5%). the method was validated by spiking dye to real samples.