immo!nvest – Die Plattform für Standorte und Immobilien

Tag: PFAS

  • PFAS in construction waste

    PFAS in construction waste

    Around 7.4 million tons of mineral construction waste are produced in Switzerland every year, with demolition, refurbishment and new construction continuing to increase the quantities. It is not only asbestos and PCBs that are problematic, but also PFAS (per- and polyfluorinated alkyl substances). These chemicals are considered carcinogenic and accumulate in the human body.

    A study by the University of Bern found up to seven PFAS substances in 20 samples of demolition material, some in concentrations of up to 5 micrograms per kilogram. Although the quantities are considered low, the research team recommends further investigations. Landfills are usually not sealed, PFAS can be washed out and thus enter the groundwater, where they pollute the food chain and drinking water.

    Measurements and new standards
    The Swiss Building Materials Association Circular Switzerland and the Federal Office for the Environment are working together with cantons and independent laboratories to determine PFAS contamination in gravel works, concrete plants and existing buildings. The investigation is nearing completion. The findings are to be incorporated into a practical guide for dealing with PFAS. The federal government is planning limit values for PFAS in contaminated sites and waste by 2026, which construction companies will have to comply with in future.

    In civil engineering, the Federal Roads Office has recommended avoiding PFAS-containing substances for the time being. Due to the lack of legislation, Astra is not yet able to enforce any bans, but is working on checklists for PFAS-free construction products.

    Health risk and circular economy
    The Federal Office of Public Health is monitoring the PFAS problem in indoor spaces and warns of its persistence. PFAS bind to materials for a long time and become problematic when abraded and inhaled, but have so far been less relevant in the living environment, as the main source remains food. According to the authorities, the risk of exposure from building rubble and landfill sites is greater. This is because rainwater washes PFAS into the groundwater and thus into the food chain. Although leachate is technically purified, the risk of uncontrolled contamination remains.

    The Building Materials Association emphasizes that the recyclability of demolition material is endangered by the new limit values. At the same time, the industry wants to keep the chemicals out of the cycle. Professional removal and disposal are possible, but it is calling for clear and practicable guidelines from the federal government.

    PFAS in Swiss soil
    A recent Swiss study shows that PFAS can now be detected in all topsoils, even in remote forest and mountain areas. Point sources such as fire extinguishing training grounds and electroplating plants increase local pollution. Agricultural soils in particular contain high PFAS levels, often caused by sewage sludge used as fertilizer. The large number of applications makes it difficult to trace the origin.

    Political debate on PFAS
    Following the detection of PFAS in meat from the canton of St. Gallen and the first bans, parliament has also taken up the issue. The authorities and the industry are working together on a mix of measures to protect the population and the environment. Environment Minister Albert Rösti confirms the seriousness of the situation. The government wants to respond with limit values, guidelines and tighter controls.

  • New silicon acids could destroy “eternal chemicals”

    New silicon acids could destroy “eternal chemicals”

    Per- and polyfluorinated alkyl substances, PFAS for short, are considered “eternal chemicals” as they do not degrade in the environment. Their highly stable carbon-fluorine bond resists light, water and microorganisms. This is precisely where the newly developed super Lewis acids come in. They exhibit extreme “electron greed” and directly attack the resistant structures of PFAS.

    Complex production with a big impact
    For a long time, these compounds were only considered a theoretical concept. Only innovative methods such as protolysis made it possible to produce them synthetically. Proven processes from carbon chemistry were transferred to silicon. The experiments were highly sensitive. They had to be carried out in an inert gas atmosphere, as even the slightest traces of oxygen or water would prevent the reactions.

    Quantum mechanics provides the key
    For the first time, the strength of these molecules was fully predicted using quantum mechanics. These calculations not only confirmed the extreme reactivity, but also enabled a precise understanding of the mechanisms. Spectroscopic methods such as NMR validated the predictions. The combination of theory and experiment is therefore a milestone in catalysis research.

    Catalysts for environmental protection
    The new super Lewis acids behave like catalysts. They change during the reaction, but regenerate again and are not permanently consumed. This means that the smallest quantities are sufficient to render highly toxic PFAS compounds harmless… A decisive advantage over previous approaches.

    With silicon-based super Lewis acids, a realistic solution to the global PFAS problem is within reach for the first time. They could become a key instrument for recycling, green chemistry and the protection of the environment and health.

  • Circular economy in the construction industry

    Circular economy in the construction industry

    Decarbonising industrial processes is a key approach to reducing CO₂ emissions. An industry roadmap presented here serves as a guide for companies to identify and implement suitable measures.

    Optimisation of concrete as a building material
    The sustainable use of concrete requires optimisation of its properties and targeted use in line with its performance. At the end of a building’s service life, options such as renovation, refurbishment, demolition with reuse of components or recycling must be carefully considered.

    Pollutant management in the circular economy
    Effective pollutant management is essential for a sustainable circular economy. This includes both the client’s disposal concept during dismantling planning and the separation of materials and pollutants during material treatment.

    Dealing with PFAS
    Per- and polyfluorinated alkyl compounds (PFAS) are a particular challenge due to their longevity and ubiquity. The event shed light on the possibilities and limitations of dealing with this group of substances.

    Innovative decarbonisation projects
    One highlight was the presentation of the world’s largest electric melting furnace for rock wool. This project shows how decarbonisation is implemented in practice and the potential that lies in the production of stone wool. The 2024 autumn event underlined the importance of a sustainable circular economy and offered practical solutions for the construction industry.