Bioremediation is a natural process, it is present in all environments; for example, the compost that is made in many homes is a natural waste transformation process that allows obtaining natural fertilizer. Science has succeeded in understanding it and intervening in it, with a procedure that uses microorganisms such as bacteria. Bioremediation as a scientific intervention stimulates the growth of certain bacteria that use the pollutants as a source of food and energy. Some contaminants that are treated with bioremediation are petroleum and some derivatives, solvents and pesticides. For more background see: Bioremediation as an intervention consists of accelerating a process that in nature takes many years, isolating it to make it more efficient, homogeneous and controlled. It is controlled through a treatment on site (in situ), through a soil management in closed autonomous units called “biopiles”, where the whole procedure is permanently monitored. For more information; In the Ministry of Environment (MMA), since 2009 there is a “National Policy for the Management of Sites with presence of Contaminants”, which guides the management to reduce risks; in 2013 the MMA approved a “Methodological Guide for the Management of Soils with Potential Presence of Contaminants”, which generates a procedure to study soils against activities with potential contamination, and proposes to develop corrective action plans when there are risks. For more information, the following links provide the policy and the guide: In the field, there is a history of natural development of bioremediation. After a long historical stage of contamination, this process has been observed spontaneously on site, very slowly. The Las Salinas project has observed and isolated it as a suitable, minimally invasive, self-regulating and silent process, which does not move contaminated soils elsewhere, but treats them, recovers them and leaves them in place. A procedure that implies a suitable option for a dense urban area. Bacteria are everywhere in massive form, in the gardens, in the parks, in our refrigerator, etc. So far, after more than 70 years of a naturally activated process, there is no record of them being a threat to populations, as they are bacteria adapted to surplus and remaining hydrocarbons, and not to human pathologies. What will be used is a bacterial community, i.e. a population composed of different bacteria, which are already in the field and have the potential to degrade hydrocarbons. This potential arises from the adaptive capacity of the bacterial community in its cohabitation relationship with pollutants. In simple terms: . These bacteria are classified within Group 1 in the Classification of Microorganisms by risk level in the ANID (ex CONICYT) Biosafety Standards Manual, which means that they are agents that are not associated with any disease. The bacteria will be used as they are on site today, i.e., within the contaminated substrate; they will be collected in biopiles, sealed mounds of soil, isolated from each other and monitored to measure the level of contamination.
During late 2015 and early 2016, Las Salinas requested the Universidad Técnica Federico Santa María (USM) to evaluate remediation strategies through two experimental studies: , which involved the use of sediments and groundwater extracted from the Las Salinas site for the development of microcosms for analysis of aerobic pilots (requiring oxygen) for bioaugmentation, biostimulation and enhanced bioremediation; and anaerobic pilots (not requiring oxygen) for bioaugmentation. In addition, five biopiles with aerated and non-aerated bioaugmentation and biostimulation treatments; and landfarming, all with satisfactory results. Also, since 2015, the land has been monitored and samples of soil and water present in the subsoil are regularly taken for study and improvement of the procedure proposed in the Environmental Impact Assessment (EIA) Sanitation for the Las Salinas Land, where the detail of all procedures likely to generate impacts can be found. They are bioremediating, at a slow and differentiated pace, on the soil and groundwater, at an average depth of 6 to 7 meters. Bacteria are self-regulating according to the “food” and energy generated by the hydrocarbons, reduced the contribution generated by the contamination, they become extinct and transform into organic material, as part of the substrate or soil. This is not possible. Contaminants are reduced and focused now and will be even during a process of soil movement and biopile assembly. The possibility of uncontrolled reproduction assumes uncontrolled contamination, and we well know that the site currently presents the remnants of an intense process of decommissioning and extraction of soils carried out during 2009-2010, so the remaining contamination is low. Moreover, in the absence or reduction of contaminants, in the same ratio bacteria are reduced. However, for all intents and purposes, and not necessarily for potential “out of control”, but as a mechanism to deliver certainty and the utmost safety, biosafety protocols are in place, the Environmental Impact Study is precise regarding the safety measures incorporated into the process. For more information: A level of bacteria movement to the surrounding dwellings or beyond is impossible, let alone in a non-homogeneous environment. The movement of bacteria is on a microscopic scale, imperceptible to human measurement standards; their world (cosmos) is reduced to a dimension not perceptible to man. For more information; They are internationally recognized local scientists. The laboratory of greater transcendence and recognition of their work is the Center of Biotechnology “Dr. Daniel Alkalay Lowitt” of the UTFSM, with reference to Dr, Michael Seager and Dr, Roberto Orellana. For further information:
