IV Conference on Soil Contamination

BLOCK 1. Bioremediation

•  Bioremediation, as a remediation technique, on its own or in conjunction with other techniques, can achieve desirable levels of decontamination.
• Phytoremediation with appropriate species can decontaminate sites with surface hydrocarbon (and metal) contamination and generate biomass for biofuel production.
• Biostimulation of soil microbial populations and bioecopiles with the application of redox gradients can achieve significant reductions of hydrocarbons and metals in the soil.
• The cleanup time is usually long and is a limiting factor for its use.
• Microbial electrochemistry as a remediation system applicable for various contaminants and matrices is in its initial phase of use. It may be a technique to be enhanced in the future.
• Electrochemical techniques are also appropriate for the treatment of contaminated water with high concentrations of metals.
• Bioremediation using fungi is a viable technique for classical remediation systems due to its low cost, low energy consumption and high efficiency in hydrocarbon degradation.
• Ecotoxicity in bioremediation processes is a necessary evaluation factor to ensure viability.

BLOCK 2. Treatment of organic compounds

• Treatment times of organic compounds (DNAPL) are often long and frequently experience rebound effects caused by contaminants stored in low permeability zones. More detailed studies are needed.
• The combined use of physicochemical and microbiological methods may be adequate to treat these conditions.
• The technique of isotope analysis makes it possible to monitor the evolution of oxidation reactions in degradation processes.
• Universities and research centers are working on projects (at different stages of development) aimed at finding new decontamination systems with a low carbon footprint.

BLOCK 3. PFAS

• It is a family formed by a high number of synthesis compounds, making their knowledge difficult. They are practically ubiquitous, difficult to degrade and at low concentrations can have harmful effects on health and the ecosystem.
• Their analysis is complex. Currently, about 50 (the most common) are analyzed in Europe. Non-specific parameters (precursors or total fluoride) are also determined.
•  Enhanced attenuation by adsorption is a sustainable system successfully applied in more than 40 sites.
•  In the future, new regulations and reference levels will determine the evolution of analytical techniques and treatment systems.