Biosorbent Efficacy of Groundnut Husk for the Elimination of Chromium from the Effluent of Mojo Tannery Industry, Ethiopia

Table 2

Functional groups of groundnut husk with or without chromium-loaded and the corresponding infrared absorption wavelengths.

Observed peak wavelength (cm^−1)	Wavelength range (cm^−1), intensity, and shape	Bond	Functional group assignment
3435–3364	3500–3200 (s, br)	O–H stretch, H–bonded	Alcohols, phenols
2931–2904	3000–2850 (m)	C–H stretch	Alkanes
1665–1641	1680–1620 (sat.),	C=C stretch	Alkenes
	1650–1600 (conj.) (w to m)
1519–1514	1620–1440 (m to w)	C=C stretch	Aromatic compounds
1268–1265	1350–1000 (s to m)	C–N stretching	Amines
1052–1033	1050 (s)	S=O	Sulfoxide
701–607	700–610 (s, br)	–C≡C–H: C–H bend	Alkynes