Extraction of Humic Acids from Different Origins: A Review

The synthesis of molecules such as humic acids is a good strategy for the remediation of eroded soils. Since the synthesis and extraction of these carbon molecules do not represent a process of energy liberation of the carbon, it is also a low-cost process. Bad practices in soils, such as the indiscriminate use of pesticides and pesticides, cause damage to the soil that can be difficult to reverse, depending on the type of exposure and resilience they have. For example, the Atlantic coast is the most affected by salinization, according to Ideam a phenomenon related to incorrect agricultural activities, devastating tourism, and the impact of the dry climate. Soil erosion is an effect that has a negative influence on activities such as agriculture since the erosion of the soils prevents or causes the agricultural activity to be low or almost nil. Humic acids are molecules that can retain cations in their macroporous structure. Therefore, it is important to study what is the affinity that these macromolecules have with the cations of Zn, Ca, K, Mg and therefore, to know with which of them the affinity is greater depending on the type of carbon studied. The objective of this monographic study is to review the conceptual part of humic acids, their different forms of extraction, and their applications reported by different authors working in this field.