Table 4: FTIR spectral characteristics of CH before and after Zn(II) biosorption.

IR peakFrequency (cm−1) before adsorptionFrequency (cm−1) after adsorptionDifference Functional group

13314.00340086Bonded –OH group
22931.422937.145.72Aliphatic C–H groups
32365.712354.28−11.43S–H stretching
41658.601646.63−11.37C=O stretching
51530.581529.79−0.79Amino/nitro compound
61393.001393.1000Nitro compound
71239.111236.26−2.85C–N stretching
81039.631039.630C–O stretching