Ecotoxicological assessment of recycled aggregate and concrete via aquatic biotests

Abstract

With the growing consumption of primary raw materials, the need for recycling of construction and demolition waste (CDW) arises. According to international and national regulations, any waste must be tested for ecotoxicity using a leaching test followed by chemical analysis and a set of aquatic toxicity biotests. Standardized leaching procedures have also been developed for construction materials and products and are used in common practice. On the other hand, studies aimed at direct determination of ecotoxicity are still lacking. Acute toxicity tests with unicellular algae, freshwater crustaceans, and marine bacteria are among the most popular for determining the ecotoxicological potential of recycled aggregates or concrete samples. The article deals with the perspective of semichronic and chronic tests with extended exposure, as well as testing of leachates obtained from leaching events for more than 24 hours. Results of performed experiments were compared and evaluated. From the point of view of sustainability, it is necessary to develop an optimal experimental design for the ecotoxicological evaluation of recycled aggregate and concrete. The conclusion of the paper is the evaluation of possible methods and their combinations.