Hen Feather: A Remarkable Adsorbent for Dye Removal - Green Chemistry for Dyes Removal from Wastewater - page 447

and 50 C Hen Feathers adsorb around 47.5, 52 and 65% of the Amaranth,
respectively, within the first one hour of adsorption from 5 × 10 -5 M solu-
tion of the dye, while for the 9 × 10 -5 M solution the amount adsorbed is 42,
47 and 60% at the same temperatures (Table 11.5). A further confirmation
of the endothermic nature of the ongoing process is made by calculating
the half-life of the process at each concentration and it is found to decrease
with increase in temperature. Almost similar observations have been made

Table 11.5 Effect of contact time on the adsorption of Azo Dyes over Hen
Feathers at different concentrations of the dye and different temperatures
(Amaranth & Tartrazine: Amount of Hen Feather = 0.01 g/25mL, pH = 2.0).
Amaranth (0.09 mM)

Amaranth (0.05 mM)

Time
(Seconds)

Amount Adsorbed ×
10 -5 (mole/g)

Time
(Seconds)

Amount Adsorbed ×
10 -5 (mole/g)

30°C 40°C 50°C 30°C 40°C 50°C

900 2.29 2.47 2.71 900 0.94 1.25 1.45

1800 2.65 2.85 3.20 1800 2.07 2.27 2.54

2700 2.95 3.26 3.64 2700 2.93 3.14 3.47

3600 3.20 3.57 4.03 3600 3.58 3.82 4.23

4500 3.44 3.79 4.31 4500 4.05 4.29 4.73

5400 3.59 3.97 4.51 5400 4.71 4.93 5.30

6300 3.70 4.09 4.65 6300 4.95 5.15 5.41

7200 3.91 4.33 4.90 7200 4.99 5.20 5.46

8100 4.06 4.40 5.02 8100 5.00 5.20 5.50

Tartrazine (0.09 mM) Tartrazine (0.05 mM)

Time
(Seconds)

Amount Adsorbed × 10 -4
(m ole/g)

Time
(Seconds)

Amount Adsorbed ×
10 -4 (mole/g)

30°C 40°C 50°C 30°C 40°C 50°C

1800 1.97 2.16 2.36 1800 1.42 1.56 1.77

3000 2.76 2.97 3.19 3000 1.98 2.15 2.45

5400 3.42 3.75 4.05 5400 2.44 2.68 3.05

7200 4.15 4.42 4.75 7200 3.01 3.31 3.79

9000 4.71 5.05 5.38 9000 3.56 3.82 4.34

10800 5.26 5.50 5.88 10800 3.71 4.03 4.45

12600 5.59 5.89 6.32 12600 3.88 4.15 4.55

14400 5.71 6.03 6.51 14400 4.00 4.25 4.68