A novel porous polymer–inorganic
hybrid biocomposite with
various functional groups (hide substance/chitosan/hydroxyapatite)
has been synthesized in simple, economic, and scalable process utilizing
leather industry solid waste and seafood industry waste composed with
hydroxyapatite. Physicochemical characterization of the material reveals
formation of composites with homogenous distribution of the constituents
in the material matrix. The composite is hard and porous (with 0.1632
cm
3
/g slit-shaped mesopores and micropores) having particle
sizes 40–80 μm and a Brunauer–Emmett–Teller
surface area of 55.54 m
2
/g. The material is polycrystalline
in nature with a fair amount of amorphous substance and less hydrophilic
in character than constituent polymers. The dye removal efficiency
of the material has been tested with two model dyes, namely, methylene
blue (MB) (cationic/basic dye) and sunset yellow (SY) (anionic/acid
dye). Optimum adsorptions of 3.8 mg MB (pH 12, RT ≈ 27 °C)
and 168 mg of SY (pH 3, RT ≈ 27 °C) have been found per
gram of the composite material. Langmuir isotherm and pseudo second
order rate models have been found to be the best-fit models to explain
the equilibrium isotherm and kinetics of the adsorption process for
both the dyes. However, higher and faster adsorption of SY in comparison
with MB indicated higher binding efficiency of the material toward
the acidic dye. Desorption of dyes from the dye-adsorbed material
was studied using a suitable eluent of appropriate pH and recycling
for five times showed without loss of efficiency. The prepared composite
showed very high dye removal efficiency toward four different commercially
used dyes (496 mg/g of Orange-NR, 477 mg/g of Red-VLN, 488 mg/g of
Blue-113 dye, and 274 mg/g of Green-PbS dye) from their individual
and cocktail solutions. It was also efficient to decolorize dye-bearing
tannery exhaust bath. Hence, waste materials generated during industrial
processes could be efficiently used for the decontamination of colored
wastewater produced by various industries.