PROJECT DESCRIPTION
BACKGROUND
Soil pollution constitutes one of the main threats to ecosystem health in Europe. Soil contamination not only degrades ecosystems and biodiversity but also poses risks to human health and jeopardizes agricultural productivity, which is essential for food security. The number of potentially contaminated sites in Europe is estimated to be between 2.5 and 2.8 million. Around 19% of all sites, equivalent to about 530,000 locations, are believed to require remediation or risk-reduction measures.
Although a diverse array of toxic xenobiotics is present at contaminated sites, Persistent Organic Pollutants (POPs) constitute the major contaminants in European soil matrices, representing 53.2% of the contaminants affecting soil. POPs are a group of chemicals that pose significant risks to human health and the environment due to their toxic properties, environmental persistence, resistance to degradation, ability to bioaccumulate in living organisms, and potential for long-range environmental transport.
The most common management approaches for POP-contaminated soils mainly include landfilling (dig and dump), ex-situ thermal desorption or chemical oxidation. The adoption of ex-situ remediation techniques requires soil excavation, mixing, and its subsequent treatment, which demands a relatively large space to carry out the procedures. Moreover, the cost of excavation is directly linked to the depth of the contamination. Regarding in-situ methods, the main treatments include thermal and chemical remediation. However, these methods have generally proven inadequate in fully resolving pollution issues, as they often transfer contaminants to another phase, such as air pollution.
In this context, studying and developing new techniques and solution approaches that achieve higher pollutant removal efficiencies at low cost and in a more environmentally friendly manner is of vital importance. Bioremediation is among the techniques that may be used for in-situ soil remediation, since it is a cost-effective and environment-friendly strategy, being neither energy-intensive nor disruptive to soil functions.
OBJECTIVES
The main objective of the LIFE InBioSoil project is to demonstrate the technical, economic and environmental feasibility of an advanced in-situ bioremediation strategy for the unsaturated zone of POP-contaminated soils. This strategy involves in the injection of a slurry into the unsaturated soil zone with the aim of promoting the bioaugmentation and biostimulation of the indigenous microbiome. The slurry will consist of organic substrates, nutrients, fungal spores and other bioproducts to stimulate aerobic in situ biodegradation of POPs, and will be injected by a system operating at low pressure to ensure spore survival and uniform distribution of reagents.
The novel solution will be complemented with predictive functional genomics to reduce time required for lab-scale solution development.
The project will be carried out at two sites in Belgium and Spain, to achieve and demonstrate the LIFE InBioSoil technology’s effectiveness across different geological, climatic and contaminant contexts.
RESULTS
- To demonstrate the benefits of low-pressure injection systems for developing an in-situ bioremediation method to remove POPs, treating an area of 300 m2 (approximately 2,700 t of contaminated soil, assuming a mean depth of 5 m and a mean density of 1.8 t/m3).
- To optimize in situ soil bioremediation strategies to reach degradation rates between 60 to 95%, comparable to ex-situ treatments.
- To demonstrate up to an 80% reduction potential in GHG emissions and 90% reduction of energy consumption in comparison to in-situ thermal desorption.
- To reduce costs by 25% compared to landfill management costs of contaminated soil (200 €/m3).