Changes of chemical properties of humic acids from crude and fungal transformed lignite

Biological conversion of low-grade coal discard to a humic substance-enriched soil-like material

“…Furthermore, studies in our laboratory on the fungal metabolism of coal discard confirmed that coal degradation by Neosartorya fischeri ECCN84, isolated from coal discard dumps, occurs coincident with elevated extracellular LAC (Sekhohola et al 2014). It was previously postulated that fungal interaction with coal particles results in bioconversion of this substrate into a mixture of heterogeneous macromolecules that are mainly humic acids (Cohen and Gabriele 1982;Henning et al 1997;Catcheside and Ralph 1999;Dong et al 2006). Indeed, microorganisms isolated from coalmines have excellent potential for coal solubilization (Malik et al 2017) and have been shown to catalyze release of complex organic moieties including polyaromatic hydrocarbons (Haider et al 2015).…”

Chemistry of metal–humic complexes contained in Megalopolis lignite and potential application in modern organomineral fertilization

“…On this basis, the humic matter content may probably be the most important parameter for the potential use of the Megalopolis lignite as an organic fertilizer and/or a feed additive (Dong et al, 2006). Lowrank coals are usually rich in humic substances (Fong et al, 2006); the minimum humic substances content in alkali-extracted solutions (at least 30 wt.% in all cases) was the basic criterion for selecting Megalopolis lignite samples (Table 1) to investigate their potential application in modern fertilizing.…”

“…Humic substances are polyelectrolyte macromolecules playing a vital role in global carbon and nitrogen cycling, as well as in the mobility and fate of plant nutrients and environmental contaminants (Dong et al, 2006). Although their chemical structure is yet not fully understood, it is recognized that humic substances are composed of hundreds of organic constituents including carbohydrates.…”

Biosolubilization of Polish Chemically Oxidated Brown Coal

“…Ponadto w tym wariancie hodowli stwierdzono najwyższą wartość E4/E6 (9,8). Wartość ta wzrasta wraz z obniżaniem się masy molowej, zawartości skondensowanych pierścieni aromatycznych oraz wraz ze wzrostem zawartości tlenu [14]. Otrzymane produkty biosolubilizacji wstępnie obrabianego węgla brunatnego scharakteryzowano metodą analizy UV-VIS i FTIR.…”