HPLC detection of synthetic dyes in residual waters from wastewater treatment using adsorption on magnetic materials

Abstract

Surface water contamination by synthetic dyes generates human and wildlife adverse health effects and causes photosynthesis decrease due to intense sun-light absorption of these pollutants. 50% of total discharged industrial effluents contain azo dyes. Congo Red is a benzidine based anionic azo dye that is usually employed in rubber, paper and plastic industries. Congo Red can cause eye and skin irritation and is potentially carcinogenic in nature. This study explores the development of a new HPLC method to detect synthetic dyes in residual waters coming from wastewater treatment technologies based on magnetic material adsorption. Cobalt ferrite (CoFe2O4) and chitosan-coated cobalt ferrite (CoFe2O4-Chit) prepared by a simple co-precipitation method were tested as adsorbents for Congo Red (CR). Effect of contact time, solution pH, and initial dye concentration were studied with respect to Congo Red adsorption efficiency. The adsorption experiments were performed at pH = 4.5 and 10.8. The highest value for the removal efficiency using the magnetic material of cobalt ferrite coated with chitosan (CoFe2O4-Chit) was obtained at pH 10.8.

Red gum-capped gold nanoparticles for electrochemical sensing of bromocresol purple in water

“…First, the oxidation peak of BCP was monitored by SWV, and then the effects of incubation time, scan rate, and pH on the oxidation peak current were discussed. Different incubation times (5,10,15,20,25,30, and 35 sec), scan rate values (0.02, 0.04, 0.06, 0.08, and 0.1 V s À1 ), and pH values (4, 5, 5.5, 6, 6.5, and 7) were tested. The oxidation peak current was calculated from the straight lines connecting the minima and maxima of each peak.…”

“…1 Therefore, it is highly necessary to develop analytical tools to detect those dyes in the aquatic system as a preliminary step before their removal and/or degradation. Different chromatographic methods such as high-performance liquid chromatography (HPLC) 4,5 and liquid chromatography/tandem mass spectrometry (LC/MS/MS) 6 are used for detecting dyes. However, these methods require sample pretreatment, extraction prior to the analysis, and expensive equipment.…”