Hen Feather: A Remarkable Adsorbent for Dye Removal - Green Chemistry for Dyes Removal from Wastewater - page 422

have been carried out at constant experimental conditions by taking a fixed
initial dye concentration, amount of Hen Feather and temperature.

11.4.1.2 Effect of Adsorbate Concentration

The rates of absorptive reactions are directly proportional to the concen-
tration of the solute. Thus, examining the effect of adsorbate concentra-
tion becomes essential [73]. The adsorption behaviors of both the dyes on
the Hen Feather have been investigated at concentrations ranging from
1 × 10 −5 mol L -1 to 10 × 10 −5 mol L -1 , at fixed pH and different temperatures
(30, 40 and 50 C). For each adsorption system a series of 100 mL gradu-
ated volumetric flasks, each containing 25 mL of adsorbate solutions at a
definite range of concentrations, has been employed at optimum pH, fol-
lowed by the procedure mentioned above.

11.4.1.3 Effect of Temperature

Temperature is an important parameter in the adsorption studies which
provides valuable information about several thermodynamic parameters
like Gibb's free energy, enthalpy and entropy, etc., along with feasibility
and endothermic or exothermic nature of the ongoing adsorption process.
The effect of temperature on the adsorption of both the azo dyes was inves-
tigated at a fixed pH, definite concentration of the dye solution and with
a fixed amount of Hen Feather. All the experiments of the present studies
have been carried out at temperatures of 30, 40 and 50 C. These temper-
atures were deliberately chosen, as temperature 30 C is treated as room
temperature and further two increments of 10 C each provide a wider
range applicable for the adsorption studies.

11.4.1.4 Effect of Adsorbent Dose

In order to study the effect of the amount of adsorbent for both the dyes,
various amounts of Hen Feathers were used and batch experiments were
conducted to determine the adsorption capacities at 30, 40 and 50 C
temperatures for 24 hours, at a particular concentration of the adsorbate
and pH of the solution. The amount of Hen Feathers added varied from
0.005 to 0.025 g and 0.005 to 0.01 g for 25 mL solutions of Tartrazine and
Amaranth, respectively.

11.4.1.5 Effect of Contact Time

In order to innovate effective modeling of the adsorption process, the
effect of contact time on the adsorption equilibrium was investigated. The