A new natural phosphate/ titanium/ chitosan (NP/TiO2/CHT) film was prepared and characterized as an adsorbent for the removal of methyl orange (MO) anionic dye from aqueous solution. Various parameters were used to investigate the adsorption behavior such as, time of contact, solution pH, initial OM dye concentration, temperature and adsorbent dose. It took 175min to reach equilibrium at a pH of 5, 0, 5 g/L of NP/TiO2/CHT film at room temperature. The adsorption of this anionic dye was well fitted by the Freundlich adsorption isotherm. Adsorption kinetics was studied using the pseudo-first-order, the pseudo-second-order and the intraparticle diffusion models. Thermodynamic parameters (ΔGo, ΔHo and ΔSo) showed that MO adsorption was…show more content… Introduction
Methyl orange (MO) is an anionic dye, it was extensively used in paper, textile and pharmaceutical industries . The MO was very toxic to human health and a small quantity of this dye in water can be toxic and highly visible, for this purpose the treatment of this dye became very important[1,2].
The low biodegradability and the existence of azo group (N═N) makes the dye toxic to human health, therefore, an efficient treatment is strongly needed. C. Bauer, P. Jacques, A. Kalt, Photooxidation of an azo dye induced by visible light incident on the surface of TiO2, J. Photochem. Photobiol. A 140 (2001) 87–92.
Various decolorization methods have been used to remove dyeing effluents such as oxidation, biological treatment, photochemical degradation membrane filtration, coagulation and adsorption. This last technique remains the most suitable for the removal of MO from wastewater because of its efficacy, operational simplicity and low cost…show more content… NP/TiO2/CHT film preparation
NP/TiO2/CHT film was prepared by mixing the reagents with proportions (10/10/80). 3 % of acetic acid was added to this product with ratio (100/5) and is kept under mechanical stirring (500 TPM) for 48 hours. The obtained product was spread on a flat surface (0.32 m2) and was kept in open air for 48 hours.
2.3. Batch adsorption experiments
A stock solution of MO was obtained by dissolving an appropriate dose of the dye in distilled water, and the concentrations used were prepared by dilution of the stock solution, a specific amounts of NP-TiO2-CHT film were added to 100 mL of the MO solution (5-200 mg L-1) in a 200ml beaker, after adsorption, samples were filtered using a 0,45 µm filter.
The concentrations of MO were measured with Jasco630 spectrophotometer (200 -1100 nm) at 465 nm, before each measurement, the base line of spectrophotometer was calibrated. The amount of MO adsorbed qe was determined by using the following