Adsorptive Removal of Various Dyes by Synthesised Zeolite

2 Adsorptive Removal of Various Dyes by Synthesised Zeolite 

Materials Sodium hydroxide and hydrochloric acid and different dyes such as methyl orange, methylene blue and safranine T were procured from Ranbaxy Fine Chemicals, New Delhi, India. Physico-chemical properties of the synthesised zeolite used in the present investigations are given in detail in Chapter 6. 

Regeneration of zeolite was done by placing the used zeolite in the furnace at around 550°C for 5 h. The catalyst is regenerated by calcination at high temperatures. By calcination, the 

The adsorbent used in the experiment was zeolite synthesised from fly ash. Dyes solution with a concentration of 1000 mg/L was prepared from analytical-grade reagent and DDW. Adsorption kinetics and isotherm experiments for all samples were undertaken using a batch equilibrium technique. The adsorption of dye was performed by shaking 0.1 g of adsorbent in 100 mL of dye solution with an initial concentration of 50-1000 mg/L at 150 rpm at different temperatures. The determination of dye concentration was done on a spectrophotometer by measuring absorbance at of 464, 630 and 560 nm for methyl orange, methylene blue and safranine T, respectively. In accordance with the Lambert-Beer law, the absorbance was found to vary linearly with concentration, and dilutions were undertaken when the absorbance exceeded 0.6. The data obtained from the adsorption tests were then used to calculate the adsorption capacity, qt (mol/g), of the adsorbent by a mass-balance relationship, which represents the amount of adsorbed dye per amount of dry adsorbent. All experimental runs were conducted at 28 2°C. 

The removal of dye from the solution and the adsorptive uptake in solid phase (q,) were calculated as follows  

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