All of adsorption, 0.01g of PPC/GO nanocomposite
All batch experiments were carried out in glass vessels usingmagnetic stirring at 200 rpm. The suspension containing 0.01 g of adsorbent samples(GO, CS/GO, CS, PPC/GO) in a 50 mlconical flasks with 30 ml of different concentration P4R aqueous solutions, wasadjusted at appropriate pH.The concentration of ponceau 4R was determinedspectrophotometrically at 507 nm. The sorption amount of P4R, qt wascalculated using mass balance equation, eq (1) Where qt is the sorption capacity of P4R per unit weight of nanocomposite at any time t mg/g,Co and Ct are initial and concentration of P4R at time t (mgL-1)respectively, calculated from absorbance value recorded by UV-Visspectrophotometer by the aid of calibration curve, W is the weight of adsorbentsin (g) and V is the volume of P4R solution in (liter) 24.
The effect of contact time on the removal efficiency of ponceau 4Rdye by GO, CS, CS/GO and PPC/GO nanocomposite was evaluated in a time period of210 min. To explore kinetics characteristics of adsorption, 0.01g of PPC/GO nanocompositesample was placed in 50 ml flask, containing 30 ml of P4R solution (2.88 ppm)at pH=7, 27 oC. The suspension was agitated at 200 rpm at different timeintervals within the range (2-210min), after which the supernatant P4R dyeconcentration was calculated using UV-Vis spectrophotometer. The isotherm studieswere done by contacting 0.
01g of PPC/GO nanocomposite, with 30 ml of P4R atdifferent initial concentration (2.4, 2.88, 3.36 ,3.
84 ,4.32) ppm and stirredtill complete adsorption. The experiments were performed at differenttemperatures (303K, 308K, 313K, 318K). Sorption isotherms are plots of theequilibrium adsorption capacity (qt) versus time to examine the remainedP4R in the solution with different conditions.
To study the pH dependency ofdye adsorption onto 0.01 g PPC/GO, the experiment was done in 30 ml ponceau 4Rsolutions with initial concentration (2.88 ppm) at pH different values (2,4,6,8,10,12)at 27oC, the buffer solution was Prepared using mixture of 250 ml (0.062N)of potassium di-hydrogen phosphate and 250 ml of dipotassium hydrogen phosphate salts25, then the pH value was adjusted by hydrochloric acid and sodiumhydroxide.