Leachates from Recycled PET Plastic Concrete: Phytotoxicity and Characterization

In the last two decades, several studies reported on plastic pollution worldwide in aquatic and terrestrial environments. Several past studies have presented plastic waste using concrete as one of the most promising solutions in plastic waste management. The most concerning part of using plastic waste in concrete as natural aggregate replacement present the deterioration of mechanical properties and increase of toxic impact in aquatic and terrestrial ecosystems. Therefore, research was done to determine the ecotoxicological potential of concrete in which 5% of recycled PET plastic replaced natural aggregate. A phytotoxicity test was performed according to ISO 20079:2005 using Lemna minor. Characterization of leachates used in phytotoxicity test was also made using ICP-OES. A comparison of inhibition of duckweed growth rate in conventional and PET concrete leachates showed no significant differences. The inhibition of growth rate in 100 g L-1 concrete leachates was significantly higher than in 0.1 g L-1 leachates. ICP-OES of concrete leachates showed no significant increase in the content of heavy metals. Based on the results of the phytotoxicity test and leachate characterization, PET concrete can be despite PET plastic content labeled as non-toxic to duckweed in aquatic environment. The presence of PET in concrete did not increase the toxic impact of concrete and its leaching behavior. Therefore, PET concrete presents an environmentally safe solution for plastic waste management and the conservation of natural resources by reducing natural aggregate consumption