Differences in humic acid structure extracted from different types of peat

Peat is an organic mineral resource. Peat contains a large amount of humic acid, and extracting humic acid from peat is a way to efficiently utilize peat. This article mainly studies the effects of using woody, herbaceous, and mossy peat as raw materials on the yield, content, and especially molecular structure of humic acid extraction, including that the oxygen-containing functional groups of humic acids, aromatic carbon content, microcrystalline structure, carbon chain structure, and degree of aromatization. The results showed that the highest yield of humic acid in woody peat was 54.33%, the yield of humic acid in herbaceous peat and mossy peat are relatively low, at 44.67% and 15.00%, respectively. while the woody peat humic acid has the lowest content, that is 38.38%. The content of humic acid in herbaceous peat was 77.33%. and the content of humic acid in mossy peat is 57.85%. Through comprehensive consider, herbaceous peat is more suitable for extracting humic acid. At the same time, this article studies the molecular structures of three peat humic acids and concludes as follows. Woody peat humic acid has the highest degree of aromatization, the highest content of benzene ring, and more functional groups such as methyl, phenol, aromatic ether, carbonyl, and hydroxyl groups. The content of methoxy and methylene groups in herbaceous peat humic acid is relatively high. Through XPS characterization analysis, it was found that the main forms of oxygen element in humic acid are C = O, C-O, and -COOH, without inorganic oxygen. The humic acid extracted from different types of peat has significant differences in yield, purity, and functional group content. Compared to woody peat and mossy peat, herbaceous peat is the most suitable raw material for extracting humic acid from peat.