PROJECT DESCRIPTION
BACKGROUND
Soil pollution constitutes one of the main threats to the health of ecosystems in Europe. There are about 2.8 million sites potentially contaminated, with 650 000 of them being identified as requiring remediation; among them, only 15% have been treated. Recent estimates found that mineral oil and polycyclic aromatic hydrocarbons, also commonly referred to as Total Petroleum Hydrocarbons (TPHs), amount to around 35% of all contaminants present in European soil. Soil remediation technologies currently available to tackle organic contaminants mainly consist of landfilling, physicochemical treatments (thermal desorption), and conventional bioremediation. The first two solutions constitute costly and energy-intensive approaches. Landfilling only consists of displacing untreated polluted soil to confinement. Thermal treatment has the clear advantage of being a short time process, but is highly energy consuming, leading to significant greenhouse gas (GHG) emissions. Moreover, it results in the generation of a “dead” – albeit cleaner – soil. Conversely, bioremediation can be performed on-site on excavated soil arranged in biopiles. These biopiles are engineered to stimulate either indigenous or allochthonous bacterial activity and to boost biodegradable metabolism, thus ensuring the breakdown of organic pollutants. This remediation technology is the most environmentally-friendly solution available on the market, as it is less energy-intensive and has no detrimental impact on soil functions. However, its major limitation is the low removal efficiency of long-chained TPHs: while thermal desorption has removal rates over 99%, bioremediation percentages might be as low as 20% for weathered TPHs. Mycoremediation can be an alternative that retains the benefits of current bioremediation techniques while significantly increasing the removal efficiency. However, it is a technology so far studied only at lab- and bench-scale.
OBJECTIVES
The LIFE MySOIL project aims to push forward the use of an emerging on site/ex-situ bioremediation technology: novel biopiling structure inoculated with specific fungal inoculum (mycoremediation). The project will develop a competitive technology to achieve recalcitrant TPH removal percentages near those currently achieved with thermal treatments, but with reduced energy requirements, lower GHG emissions, reduced costs, and limited reagents to nutrient addition. The process will also enable the valorisation of an abundant agricultural waste (spent mushroom substrate).
The objectives of the project are fully in line with the current and the upcoming EU Soil Strategy, aiming to remediate contaminated sites so that by 2050 soil pollution will no longer pose a health or environmental risk. The project will also contribute to European policies dealing with efficient resource management, as it foresees the use of spent mushroom substrate and other agroforestry wastes as bulking agents in the biopiles.
RESULTS
Expected results:
- Removal of petroleum-derived organic pollutants (TPHs) from aged industrial contaminated soils over 90%, to below legal limits for soil reuse;
- Reduction of soil toxicity by more than 75%, in order to obtain a treated soil with a quality compatible with industrial and/or residential uses and recovering the biological functionalities of the soil;
- Reduction of the environmental impacts compared to the thermal desorption scenario: reduction of energy consumption by 90%, 55% of global warming reduction and 55-70% reduction in toxicity;
- Valorisation of 100 m3 of agro-industrial waste (spent mushroom substrate and lignocellulosic waste) as fungal inoculum amendment, promoting circular economy; and
- Reduction of the investment and operational costs at full-scale remediation compared to the thermal desorption scenario: expected costs below 75 €/m3, thus reducing the costs of the baseline scenario by at least 25%.
