Treatments and technologies for the remediation of environmental pollution
Introduction
Hello! It is a pleasure to meet you again. Throughout these sessions, we have learned basic concepts related to environmental systems, the environment, and the impacts generated by the presence of pollutants.
The classification of pollutants and how they can be mobilized in soil or water, and the types of degradation that occur, have been reviewed.
In the same way, the Mexican legal framework applicable to the prevention, control, and treatment of contaminated sites has been known, identifying the standards that could be applied to analyze contaminated sites and evaluate the remediation processes to which they are subjected.
In this class, we will begin with the analysis of the existing treatments and technologies used for the remediation of environmental contamination in soil and water. These technological proposals will allow knowing the fundamentals and application cases for decontamination.
We hope it will be of great use to you.
Content developement
Treatment of environmental contamination of water and soils
In addition to principles, i.e., physical, chemical, or biological, remediation technologies can be classified Depending on the way they are applied:
- in situ, that act on the pollutants in the place where they are located, and treatments
- ex-situ, which requires the previous excavation of the soil for its subsequent treatment, either in the same place (In-situ treatment) or in external facilities that require the transport of the contaminated soil (off-site treatment).
In-situ treatments require less handling but are generally slower and more difficult to implement given the difficulty of bringing decontamination agents into close contact with all contaminated soil mass.
Ex-situ treatments are usually more expensive but also faster, usually achieving a more complete recovery of the affected area.
Depending on the objective pursued, a distinction can be made between:
- Containment techniques, which isolate the pollutant in the soil without acting on it, generally by applying physical barriers to the soil.
- Confinement techniques, which reduce the mobility of pollutants in the soil to prevent their migration by acting directly on the physicochemical conditions under which the pollutants are found.
- Decontamination techniques, aimed at reducing the concentration of pollutants in the soil.
As mentioned above, the treatments are classified according to the objective and also based on the conditions of the contaminated site (degree of contamination, contaminant (s), time of contamination, time available to carry out the remediation, available infrastructure, economic resources available, among others.
The implementation of a remediation strategy obeys a series of procedures within the regulatory framework that must be followed with fidelity.
The following link presents the requirements and procedures necessary for the implementation of remediation services for contaminated sites. The costs associated with such activity are also mentioned.
As you can see, knowledge of the environmental legal framework is necessary to understand the procedures mentioned on the website.
Next, the environmental technology treatments are listed according to the objective and the application, according to what was explained in previous sections. I invite you to review them, they will be explained in detail in later classes.
Likewise, the following table lists the pollutants that can be successfully treated with the aforementioned environmental technologies. It is important to note that each technology belongs to a group according to the principles of operation, i.e., physical, chemical, biological, and these will be reviewed in detail in the next class.
In this session, we begin with the general knowledge related to the technologies for the decontamination of sites impacted by a wide variety of pollutants.
In your immediate environment, place an environmental system contaminated with one of the listed compounds and select one of the environmental technologies that have been successfully tested for the elimination, containment, r confinement of the compound.
It is time to start with the integration of the knowledge that you have acquired so far, remember that for comprehensive training, it is important to apply theoretical knowledge not only from this class but from other complementary ones.
Analyze the criteria for the classification of decontamination technologies and reflect on the previous knowledge that allows you to categorize them in this way or in some different way. Think about the enormous possibility that exists for the development of new technologies or sequential deamination plans with existing or new technologies, as required by the type of contamination present.
Conclusion
There are different attributes used for the classification of site decontamination systems, they can be grouped by the place where they are executed, i.e., In situ – Ex situ, by the implementation objective, i.e., containment, confinement, decontamination, by the principle of operation, i.e., physical, chemical or biological.
Knowing the operating principles or the criteria under which these technologies were classified will allow the establishment of clear procedures and the necessary conditions to complete a decontamination protocol.
Information sources
- Lehr, J. H., & Wiley, J. (Eds.). (2004). Wiley’s remediation technologies handbook: major contaminant chemicals and chemical groups. John Wiley & Sons.
- Hussain, C. M. (Ed.). (2020). The Handbook of Environmental Remediation: Classic and Modern Techniques. Royal Society of Chemistry.