Several biological approaches such as bioaugmentation, biostimulation, and biocontrol have been used to improve soil health and remediate polluted environments. These methods utilize microbial inoculants, biofertilizers, organic amendments, and bio-based chemicals. Compared to chemical pesticides and fertilizers, biofertilizers offer many advantages, including reduced environmental impact, lower human health risks, more targeted action, and the ability to self-regulate through plant and microbial interactions.
Various treatment techniques for soil pollution can be classified by the type of treatment (physical or chemical), location (in-situ or ex-situ), or the environmental element being treated (air, water, or soil). Biological processing techniques, particularly bioremediation, are considered environmentally friendly and have shown promise in combating the negative effects of soil pollution
Types of Soil Pollution and Treatment Strategies
Oil pollution leads to the contamination of soil with petroleum hydrocarbons, heavy metals (such as cadmium, zinc, and lead), and compounds like polychlorinated biphenyls (PCBs). Strategies for soil treatment are focused on three key approaches:
⦁Extracting pollutants from the soil or separating them from the environment.
⦁Changing or removing pollutants through chemical, physical, or biological processes.
⦁Immobilizing pollutants to halt their harmful effects.
In some cases, a combination of these approaches may be necessary to fully remediate the contaminated soil.
Bioremediation
Bioremediation is the process of using living organisms, particularly microorganisms, to break down pollutants and contaminants in the environment, transforming them into less harmful forms. It capitalizes on microorganisms' ability to degrade hydrocarbons, converting them into simpler components that can be used by other organisms as nutrients or safely released into the environment. This degradation typically results in organic components being converted into water, carbon dioxide, and other inorganic compounds. In addition to microorganisms, certain plants also contribute to the biodegradation of hydrocarbons. Bioremediation can occur naturally or be enhanced by introducing specific microorganisms or plants into contaminated soils, depending on the severity of contamination. These organisms help to break down or neutralize harmful pollutants, converting them into harmless or less toxic compounds. Microorganisms, including yeasts, bacteria, and fungi, play a key role in breaking down petroleum hydrocarbons and other pollutants. Among these, bacteria stand out for their rapid growth and high density, which allow them to efficiently reduce petroleum pollutants in contaminated soils.