
Associate Professor Štibrányi (FChPT STU), an expert on the issue of PCB substances in Strážske, stated in an interview for Rádio Slovensko that humic acids can capture 90-95% of PCB substances in water within a very short time. [Link to the interview, January 21, 2025 (SK)]
This year, the former chemical plant Chemko Strážske is beginning the disposal of the first batch of waste from PCB production. 150 tons of this waste will be transported to an incinerator and safely destroyed. Additional stored waste will follow in the coming period. [SITA January 7, 2025 (SK)]
However, the biggest problem remains the vast area contaminated with PCB substances, which leaked from production into the surrounding environment for more than 40 years. PCB residues are found in the soil over an area of approximately 25,000 hectares and in the waters of Zemplín and its surroundings. This area cannot be easily decontaminated, so alternative methods must be sought to prevent PCB substances from entering plants, animals, and the entire food chain.
Associate Professor Štibrányi has studied several different sorbents, and humic acids have proven to be among the most effective. In his tests, he demonstrated that the product HUMAC® Agro can capture up to 90% of PCB substances within just 25 minutes of mixing in a solution. This indicates that sorption is very rapid, and humic acids bind PCB substances (most congeners equally) almost immediately upon contact.
The results of experiments conducted by the National Agricultural and Food Centre – Research Institute of Agroecology (NPPC – VÚA Michalovce) in 2020 also showed that humic acids can prevent PCB substances from penetrating plants. In radishes grown in soil contaminated with PCB substances from Strážske, the content of these substances was reduced by up to 73.20% in the root and up to 61.71% in the leaves.
Humic acids thus bring hope that one of the largest ecological disasters in Central Europe has a solution that is both simple and economically feasible.