Since the beginning of the agrarian revolution and later the industrial revolution, continental soils have been the most damaged.
Industrial activity, being an activity of transformation of raw materials into manufactured materials, generates waste that can potentially harm nature.
Although industrial activity is not the only one responsible for soil degradation, it is the most important and we will deal with this in this publication.
Soil contamination can occur in any industry, in any commercial activity, or even in any human activity since soil contamination can occur due to any of the following aspects:
- Incorrect storage of products and/or residues of human activity.
- Uncontrolled dumping of waste.
- Garbage derived from human activity.
- Burying waste, directly or in containers.
- Leaks in storage tanks or containers.
- Incorrect use of pesticides, fertilizers, etc.
- Deposition of atmospheric pollutants.
- Due to the hydrocarbon spill.
Soil contamination by hydrocarbons
In this case, one of the most covered covers in the press worldwide, we want to talk about hydrocarbon pollution.
This is one of the industries that historically have had the most risks and challenges with soil contamination since the handling of large amounts of chemical compounds increases the risk of contamination due to their handling, storage, and transport.
Soil contamination, precisely, is understood as an increase in the concentration of chemical compounds in the ground that can cause changes that are detrimental to nature, which are widely spread.
Causes of soil contamination by hydrocarbons
The main causes of soil contamination by hydrocarbons are due to the difficult handling in the extraction and transport of fossil fuels, added to the little control that many of the producing countries have of accidents that occur in this industry.
In Europe, there are areas affected by accidental, illegal or even intentional discharges, in fact, there is a public register of contaminated soils.
In Spain, this record is made through potentially polluting activities of soils as established by Real Decreto 9/2005, de 14 de enero. The soils that are finally classified as contaminated, based on the criteria established in said Real Decreto, must be cleaned and recovered by the responsible party for possible subsequent use, whether industrial or otherwise.
It is also true that in recent decades investment in the development of innovative techniques for the recovery of contaminated soils has increased, as well as patents and projects dedicated to this issue at the European level.
The industry or trade related to hydrocarbons and fossil fuels (extraction, refining, transportation, wholesale, trading, etc.) is one of those activities that must periodically report their activity and status reports to the competent administration.
Bioremediation of hydrocarbon contaminated soil
As mentioned, contaminated soils must be recovered until the values of the pollutants present are within the standards established in each case. There are different technologies for this, which may vary depending on the type of pollutant.
Leaving aside the techniques of containment or isolation of soils contaminated with physical barriers or confinement techniques, since they do not allow recovery, but rather the “non-expansion” of contamination, we can speak of in situ treatments or ex-situ treatments such as two large groups.
For obvious reasons, ex-situ treatments are usually more expensive, since they involve the removal of the entire amount of contaminated soil for treatment in suitable places.
This ex-situ method requires the stages of excavation, transportation, treatment in sewage plants, return and burial, making soil treatment more expensive and making it unfeasible for many companies that handle hydrocarbons.
In situ treatment
In situ treatments are, generally, the most used. Among them we can find a great variety, to mention a few:
- Flushing, which consists of flooding the soil to drive pollutants to a place from which they can be easily extracted.
- Physical-chemical treatments such as those that use columns of air to volatilize pollutants.
- Phytoremediation uses plant elements that allow metabolization.
- Biological treatments.
Biotechnology for soil recovery
By Amapex Environement SL
hydrocarbons, soils contaminated