saideh bagheri

The present study focuses on the development of an effective methodology to obtain the optimum removal conditions assisted by ultrasonic to maximize the simultaneous removal of Bismarck Brown (BB) and Thymol Blue (TB) dyes on to TiO2 nanoparticles loaded on activated carbon (TiO2 -NPs-AC) in aqueous solution using response surface methodology (RSM). The experimental equilibrium data were fitted to the conventional isotherm models such as Langmuir, Freundlich, Temkin and Dubinin–Radushkevich. The Langmuir isotherm was found to be the best model for the explanation of experimental data.From the Langmuir isotherm, the maximum monolayer capacity (Qmax) was found to be 100 and 50 mg g-1 for BB and TB, respectively at optimum conditions. Kinetic evaluation of experimental data showed that the BB and TB adsorption processes followed well pseudo-second-order.

A new kinetic spectrophotometic method for the determination of trace amount Chromium (III) in Teareal samples has been described based on it s the catalytic effect on the oxidations of 1 - ( 2 –PyridylAzo ) - 2 - Naphthol, (PAN), by potassium bromated in sulfuric acid. The reaction is followedspec- trophotometrically by measuring the decrease in the absorbance at 469 nm. Under the optimumconditions of0.2 molL-1 sulfuric acid, 1.0 × 10-4 molL-1, 1- ( 2 -PyridylAzo ) - 2 - Naphthol, (PAN),0.01 molL-1 potassium bromate at 35oC, calibration graph in the rang of 0.001-0.06 ngL-1 Chromium(III). Concentration was obtained with detection limit of 0.2303 g mL-1 by the fixed-time method of5.5 min. The relative standard deviation for 0.05AngL-1 Chromium (III) is %90. No serious interferencewas identified. The applicability of the method was demonstrated by the determination of theChromium (III) in Water, Vegetables and blood samples.