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 (۲-(۴- Dimethylaminophenylazo) benzoic acid), methylene orange (۴-[۴-(Dimethylamino) phenylazo]benzenesulfonic acid sodium salt) and methylene blue (۳,۷-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 (۱-۵ mg L-۱) as an organic dye by titanium dioxide (TiO۲) nanoparticales in presence of UV radiation. Based on results, the COFs/TiO۲ has good agreement with the Langmuir adsorption isotherm model with favorite coefficient of determination (R۲= ۰.۹۹۸۹). The recovery of dye removal based on semi-degradation/adsorption of COFs/TiO۲ and adsorption of COFs were obtained ۹۸.۷% and ۴۸.۳%, respectively (RSD less than ۵%). The method was validated by spiking dye to real samples.

کلیدواژه ها:

Carbon nanostructures ، Carbon organic frameworks ، Dye removal ، Semi degradation-adsorption solid phase extraction ، Titanium dioxide ، UV radiation