Simultaneous devulcanization and denitrification: a novel approach for valorization of both ground tire rubber and nitrate-containing wastewater

• Published in: Biodegradation (Dordrecht) 2025-02, Vol.36 (1), p.10
• Main Authors: Çataklı, Tercan, Erguder, Tuba Hande
• Format: Article
• Language: English
• Subjects: Aquatic Pollution; Biodegradation, Environmental; Biological effects; Biological wastewater treatment; Biomedical and Life Sciences; Bioreactors; Circular economy; Denitrification; Desulfurization; Desulfurizing; Enrichment; Fourier transforms; Geochemistry; Infrared spectroscopy; Leather; Life Sciences; Microbiology; Nitrate removal; Nitrates; Nitrates - metabolism; Nutrient removal; Nutrient sources; Original Paper; Oxidation; Rubber; Rubber - chemistry; Rubber - metabolism; Sewage - microbiology; Sludge; Sludge digestion; Soil Science & Conservation; Spectroscopy, Fourier Transform Infrared; Sulfur; Sulfur - metabolism; Sulfur removal; Sulphur; Sustainable development; Terrestrial Pollution; Tires; Waste Disposal, Fluid - methods; Waste Management/Waste Technology; Waste Water Technology; Wastewater; Wastewater - chemistry; Wastewater treatment plants; Water Management; Water Pollutants, Chemical - metabolism; Water Pollution Control
• ISSN: 0923-9820; 1572-9729; 1572-9729
• DOI: 10.1007/s10532-024-10105-1

This study focused on a new approach for valorization of both ground tire rubber (GTR) and nitrate-containing wastewater via simultaneous devulcanization and denitrification. Initially, sulfur-based autotrophic denitrifiers were successfully enriched from three different seed sludge sources, biological nutrient removal (BNR) sludge, anaerobic digester sludge and BNR sludge of a leather organized industrial zone WWTP. Average nitrate removal efficiencies were 96–98%. Biological devulcanization (biodevulcanization) of GTR was later investigated with these enriched cultures. Results revealed that biodevulcanization was only achieved with the culture enriched from BNR sludge of the leather organized industrial zone WWTP, as 3.9% sulfur removal (desulfurization efficiency). Metal sulfate precipitation was speculated to cause an underestimation of the desulfurization ratio. Fourier-transform infrared spectroscopy (FTIR) results demonstrated a decrease in the intensity of the C–S bonds and an increase in intensity of S–O bonds in treated GTR samples. This was attributed to the oxidation of sulfidic crosslinks, i.e. verification of biodevulcanization. This study indicated that simultaneous biodevulcanization and denitrification could be a promising process for valorization of both GTR and nitrate-containing wastewater which in turn would support circular economy and sustainable development.