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Adsorption of Bipyridylium Herbicides by Humic Acid
Author(s) -
Khan S. U.
Publication year - 1974
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1974.00472425000300030003x
Subject(s) - chemistry , humic acid , adsorption , paraquat , diquat , inorganic chemistry , ion exchange , potentiometric titration , ion , nuclear chemistry , organic chemistry , fertilizer
The adsorption of paraquat (1,1′‐dimethyl‐4,4′‐bipyridylium dichloride) and diquat (1,1′‐ethylene‐2,2′‐bipyridylium dibromide) by various cation‐saturated humic acids was investigated. The cation order for increasing adsorption for the two herbicides was nearly the same and followed the sequence: Al 3+ < Fe 3+ < Cu 2+ < Ni 2+ < Zn 2+ < Co 2+ < Mn 2+ < H + < Ca 2+ < Mg 2+ . It was suggested that the colloid geometry of humic material and the shape, size and nature of bipyridylium cation would influence the adsorption of the herbicide. By infrared spectroscopic and potentiometric techniques evidence was procured for the involvement of ion‐exchange and charge transfer mechanisms in the adsorption of bipyridylium herbicides by humic acid.