Table 3: FTIR spectral characteristics of CH before and after Ni (II) removal.

IR peakFrequency (cm−1)
before adsorption
Frequency (cm−1)
after adsorption
Difference Functional group

13314.00Bonded –OH group
22931.422942.8511.43Aliphatic C–H groups
32365.712354.28−11.43S–H stretching
41658.601652.33−6.27C=O stretching
51530.581526.94−3.64Amino/nitro compound
61393.001387.30−5.70Nitro compound
71239.111233.41−5.70C–N stretching
81039.631056.7317.10C–O stretching