4.1 Introduction
73
(G
o ), standard enthalpy change (H
o ) and standard entropy change (S
o ), while the
first-order and pseudo-second-order kinetic models were used to explain kinetic data
for the grafted cross-linked beads. Desorption experiments were performed to obtain
the cost effectiveness of grafted cross-linked beads.
4.2 Experimental
4.2.1 Materials
The chitosan particles were acquired from LabChem with a relative molecular
mass of 400 kDa and a degree of deacetylation of 74%. Aniline was procured
from AEC AMERSHAM (PTY) LTD (99.5%, extra pure). Ammonium persulfate (>98%), ethanol (>99%), hydrochloric acid (99%), 1-Methyl-2-pyrrolidinone
(>99%), sodium hydroxide (>99%), acetic acid (>99%), glutaraldehyde and
ethylenediamine tetra-acetic acid (EDTA) were acquired from Sigma-Aldrich.
Deionized water was generated by means of a purified water dispenser (Ultima
888 water distiller) and as used in all solutions formulation. The solution’s pH was
calculated by means of a pH metre (Hanna HI 8421), procured from Sigma-Aldrich.
For adsorption experiments, a shaker (Labcon incubator) was used, and a stirring
velocity of 120 rpm was sustained. Spectrophotometer for atomic adsorption (Variant
SpectrAA-10) was applied to verify the quantity of cadmium and lead ions adsorbed.
4.2.2 Preparation of Adsorbate
The standard solution of Cd(II) and Pb(II) in distilled water was processed by sequentially breaking down the amount needed of cadmium chloride and Pb(NO 3 ) 2 . The
standard solution to preferred initial concentrations of 40, 80, 120, 180 and 220 mg/L
was then dissolved in distilled water.
4.2.3 Adsorbent Preparation
4.2.3.1 Chitosan Beads Production
In 1 L of 3.0% (v/v) acetic acid solution, 75.3 g of chitosan granules were broken
down. The chitosan prepared solution for the removal of toxic substance was sieved
via a polystyrene membrane filter with mesh 100 µm. Development of chitosan gel
beads arose when 1 M of sodium hydroxide solution interacted with the filtrate.
73
(G
o ), standard enthalpy change (H
o ) and standard entropy change (S
o ), while the
first-order and pseudo-second-order kinetic models were used to explain kinetic data
for the grafted cross-linked beads. Desorption experiments were performed to obtain
the cost effectiveness of grafted cross-linked beads.
4.2 Experimental
4.2.1 Materials
The chitosan particles were acquired from LabChem with a relative molecular
mass of 400 kDa and a degree of deacetylation of 74%. Aniline was procured
from AEC AMERSHAM (PTY) LTD (99.5%, extra pure). Ammonium persulfate (>98%), ethanol (>99%), hydrochloric acid (99%), 1-Methyl-2-pyrrolidinone
(>99%), sodium hydroxide (>99%), acetic acid (>99%), glutaraldehyde and
ethylenediamine tetra-acetic acid (EDTA) were acquired from Sigma-Aldrich.
Deionized water was generated by means of a purified water dispenser (Ultima
888 water distiller) and as used in all solutions formulation. The solution’s pH was
calculated by means of a pH metre (Hanna HI 8421), procured from Sigma-Aldrich.
For adsorption experiments, a shaker (Labcon incubator) was used, and a stirring
velocity of 120 rpm was sustained. Spectrophotometer for atomic adsorption (Variant
SpectrAA-10) was applied to verify the quantity of cadmium and lead ions adsorbed.
4.2.2 Preparation of Adsorbate
The standard solution of Cd(II) and Pb(II) in distilled water was processed by sequentially breaking down the amount needed of cadmium chloride and Pb(NO 3 ) 2 . The
standard solution to preferred initial concentrations of 40, 80, 120, 180 and 220 mg/L
was then dissolved in distilled water.
4.2.3 Adsorbent Preparation
4.2.3.1 Chitosan Beads Production
In 1 L of 3.0% (v/v) acetic acid solution, 75.3 g of chitosan granules were broken
down. The chitosan prepared solution for the removal of toxic substance was sieved
via a polystyrene membrane filter with mesh 100 µm. Development of chitosan gel
beads arose when 1 M of sodium hydroxide solution interacted with the filtrate.