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Golf Course Construction and Renovation
Published in L.B. (Bert) McCarty, Golf Turf Management, 2018
Humic acid is commercially produced by adding a dilute (~2%) alkali, usually sodium hydroxide, to a humus-bearing material, usually leonardite or possibly coal, lignite, or well-composed peat. Leonardite is a lignitic–organic material related to coal. The sodium hydroxide separates the humus from the alkali-insoluble plant residues present in the leonardite. Acid is added to this humus extraction that produces lignin, humic acid, and fulvic acid. About 50% of the leachate is insoluble precipitate of lignin, which is the portion of plants that is difficult to decompose. The other 50% of the leachate is the water-soluble portion—40% of this being humic acid and the other 10% fulvic acid. The exchange sites of humic acid are filled predominantly with protons (H+ ions)—hence, the name—while fulvic acid contains much of the biostimulant-like materials. These acids have a minimum effect on soil pH because the acids are insoluble in water.
Enzymatic Solubilization of Coal
Published in Donald L. Wise, Bioprocessing and Biotreatment of Coal, 2017
Martin S. Cohen, Bary W. Wilson, Roger M. Bean
Leonardite coal was used as a model coal for most of the results reported here. Leonardite is a highly oxidized form of lignite with a typical oxygen content of 28 to 29%, compared with 19 to 20% for other lignites. Leonardite occurs at shallow depths overlying or grading into the harder and more compact lignite. Leonardite is associated with virtually all lignite outcrops in North Dakota, where it is mined commercially. Lignite can be converted into leonardite by heating it to 150°C for 16 h in the presence of oxygen [13]. The elemental composition (based on 100 carbons) of the leonardite used in the experiments reported here is C100 H78 O41 N1.
Effects of leonardite on the coastal saline soil improvement
Published in Chemistry and Ecology, 2020
Jie Wang, Jun Wu, Jian Lu, Guodong Yuan
The addition of leonardite increased the content of organic matter. The activity of urease and phosphatase subsequently increased with the accelerated hydrolysis of urea and the decreased content of soluble phosphate in the soil. Leonardite increased the C and N content as well as C/N in the soil colloid of the incubated soil. However, the leonardite addition had little effect on the soil texture and mineral composition during the short-term incubation. Overall, the application of leonardite would introduce organic matter to promote the activity of soil microbe and relative enzyme, and the soil ecosystem would thereby get improved.
An efficient technique for the purification of fulvic acid extracted from leonardite
Published in Chemical Engineering Communications, 2023
Md. Zahidul Islam, Aynur Manzak, Yasemin Yıldız, Yavuz Derin, Raşit F. Yılmaz, M. Shahinuzzaman, Ahmet Tutar
Leonardite (LD) is a coal-like natural organic material with lower compactness (Simandl et al. 2001; Olivella et al. 2002) and higher porosity, oxygen level, and organic matter content than coal. LD contains 35-80% humic acids, which can be easily pulverized at 20-40% moisture content. Its density and pH range between 0.75–0.85 g/cm3 and about 3-5, respectively, and well soluble in basic medium (KOH, NaOH) but highly insoluble in water. LD forms bright, black, foamy, colloidal, and oily compounds with a pH of 8 to 9 (Olivella et al. 2002). LD and its derivatives are commonly used for industrial purposes such as cosmetics, pharmaceuticals, filtering systems, drilling, and animal feed (Islam et al. 2018). LD is widely used as natural fertilizer in organic agriculture, which acts as a soil conditioner due to the presence of humic substances that increase the soil’s water-holding capacity and its conductivity (Ricca et al. 1993; Piccolo et al. 1997; Lamar et al. 2014). Kaz mountains in Turkey are an essential source of lignite beds with abundant humic substances. The presence of good-quality humic acids (HAs) and fulvic acids (FAs) in these mountains makes this region more valuable geographically. HAs are insoluble in acidic medium, leaving humin as an insoluble residue (Klencsár and Köntös 2018). FAs are one of the humic substances that are soluble in both alkali and acid mediums. FAs are mainly complex multi-ligand simple organic compounds with excellent physicochemical properties, low molecular weight, and a wide pH range. Fulvic acids consist of several functional groups and negatively correlate with magnesium and potassium usable concentrations (Rashid et al. 2018). Thus, FAs have many chemical and biological applications in medicine, the environment, agriculture, and material science (Gong et al. 2020). Besides, FAs are highly stable and can also be used as a healthy adsorbent of heavy metals such as cadmium and chromium (Ali et al. 2018; Rashid et al. 2018; Gong et al. 2020).