Hen Feather: A Remarkable Adsorbent for Dye Removal - Green Chemistry for Dyes Removal from Wastewater - page 419

water [70]. Feathers are modified by tannic acid and kinetics of adsorption
of Zn 2+ by treated and untreated feather has been studied as a function of
the weight gain of tannic acid, pH of metal solution, etc.

11.3.1 Development of Adsorbent Material

As described earlier, hen feathers usually contain a soft barb part and a
hard rachis. The feathers procured from poultry were dirty and about 1 cm
in length. To remove the dirt, blood stains and odor from the feathers they
were first agitated in a pool of distilled water bath and then rinsed several
times by doubly distilled water. The washed feathers were then dried and
their soft barbs were cut into small pieces, each of about 0.1 mm length,
with the help of a sharp blade, and middle rachis were removed and dis-
carded. The barbs thus obtained were then treated with 30% v/v hydrogen
peroxide for about 24 hours to oxidize the adhering organic material. Next,
for the removal of moisture, the material obtained was kept in an oven at
100 C for 12 hours and activated adsorbent thus obtained was stored in a
vacuum desiccator until used.

11.3.2 Characterization of Adsorbents

11.3.2.1 Chemical Analysis

The chemical analysis of activated Hen Feather has also been carried out
by standard methods [71] and reveals that Hen Feather contains protein
contents of around 84 percent along with several inorganic constituents
like calcium, magnesium, selenium, zinc, etc. The raw feather is relatively
insoluble and possesses a very low digestibility of five percent due to the
high keratin contents and the strong disulphide bonding of the amino
acids. The chemical constituents of feather have been portrayed elsewhere
[17-26].

11.3.2.2 Analysis of Physical Properties

The porosity and density of activated Hen Feathers have been ascertained
by standard procedures using mercury porosimeter and specific gravity
bottles respectively. Amongst various physical parameters of activated Hen
Feathers, surface area was found to be 1170.6 (cm 2 .g -1 ), density 0.3834
(g.mL -1 ), porosity 74% and loss on ignition was obtained at 2.63%.
The nature of Hen Feather has been determined by dipping a weighed
quantity of each adsorbent in 25 mL of distill water (pH = 7.0) in a 100 mL