Abstract
The acidic functional groups content, pK value, DELTAH and DELTAS of humic acid (HA) and nitro-humic acid (NHA) were determined by potentiometry, conductometry and calorimetric titration. The thermodynamic parameters of carboxylic groups and phenolic hydroxyl groups of humic acid are similar to that of simple hydroxy-benzoic acid. The configuration sites of acidic functional groups in humic acid from different coals are different. The carbonyl groups on aromatic rings are probably ortho to phenolic -OH for HA and NHA extracted from Huangxian's brown coal and Japanese lignite, while those from Lingshi's weathered coal are not. The weak -COOH groups of the latter possess higher chemical activity. The -COOH content in HA increases, phenolic -OH group decreases and the chemical acidity of acidic functional groups increases when HA is oxidized by nitric acid. (14 refs.)
Citation Formats
Shanxiang, Li, Shuhe, Sun, and Zhai Zongxi, Wu Qihu.
The acidic functional groups of humic acid.
China: N. p.,
1983.
Web.
Shanxiang, Li, Shuhe, Sun, & Zhai Zongxi, Wu Qihu.
The acidic functional groups of humic acid.
China.
Shanxiang, Li, Shuhe, Sun, and Zhai Zongxi, Wu Qihu.
1983.
"The acidic functional groups of humic acid."
China.
@misc{etde_5433916,
title = {The acidic functional groups of humic acid}
author = {Shanxiang, Li, Shuhe, Sun, and Zhai Zongxi, Wu Qihu}
abstractNote = {The acidic functional groups content, pK value, DELTAH and DELTAS of humic acid (HA) and nitro-humic acid (NHA) were determined by potentiometry, conductometry and calorimetric titration. The thermodynamic parameters of carboxylic groups and phenolic hydroxyl groups of humic acid are similar to that of simple hydroxy-benzoic acid. The configuration sites of acidic functional groups in humic acid from different coals are different. The carbonyl groups on aromatic rings are probably ortho to phenolic -OH for HA and NHA extracted from Huangxian's brown coal and Japanese lignite, while those from Lingshi's weathered coal are not. The weak -COOH groups of the latter possess higher chemical activity. The -COOH content in HA increases, phenolic -OH group decreases and the chemical acidity of acidic functional groups increases when HA is oxidized by nitric acid. (14 refs.)}
journal = []
volume = {11:3}
journal type = {AC}
place = {China}
year = {1983}
month = {Sep}
}
title = {The acidic functional groups of humic acid}
author = {Shanxiang, Li, Shuhe, Sun, and Zhai Zongxi, Wu Qihu}
abstractNote = {The acidic functional groups content, pK value, DELTAH and DELTAS of humic acid (HA) and nitro-humic acid (NHA) were determined by potentiometry, conductometry and calorimetric titration. The thermodynamic parameters of carboxylic groups and phenolic hydroxyl groups of humic acid are similar to that of simple hydroxy-benzoic acid. The configuration sites of acidic functional groups in humic acid from different coals are different. The carbonyl groups on aromatic rings are probably ortho to phenolic -OH for HA and NHA extracted from Huangxian's brown coal and Japanese lignite, while those from Lingshi's weathered coal are not. The weak -COOH groups of the latter possess higher chemical activity. The -COOH content in HA increases, phenolic -OH group decreases and the chemical acidity of acidic functional groups increases when HA is oxidized by nitric acid. (14 refs.)}
journal = []
volume = {11:3}
journal type = {AC}
place = {China}
year = {1983}
month = {Sep}
}