Tire pyrolysis wastewater treatment by a combined process of coagulation detoxification and biodegradation

Recycling waste tires through pyrolysis technology generates refractory wastewater, which is harmful to the environment if not disposed properly. In this study, a combined process of coagulation detoxification and biodegradation was used to treat tire pyrolysis wastewater. Organics removal characteristics at the molecular level were investigated using electrospray ionization (ESI) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The results showed that nearly 90% of the organic matter from the wastewater was removed through the process. Preference of the two coagulants for different classes of organics in tire pyrolysis wastewater was observed. The covalently bound inorganic organic hybrid coagulant (CBHyC) used in this work had a complementary relationship with biodegradation for the organics removal: this coagulant reduced toxicity and enhanced the biodegradation by preferentially removing refractory substances such as lignin with a high degree of oxidation (O/C > 0.3). This study provides molecular insight into the organics of tire pyrolysis wastewater removed by a combined treatment process, supporting the advancement and application of waste rubber recycling technology. It also contributes to the possible development of an effective treatment process for refractory wastewater. (C) 2021 The Authors. Published by Elsevier B.V. on behalf of Chinese Society for Environmental Sciences, Harbin Institute of Technology, Chinese Research Academy of Environmental Sciences.

Automated summary

In this study, a combined process of coagulation detoxification and biodegradation was used to treat tire pyrolysis wastewater, achieving a removal rate of nearly 90% of organic matter. Two different coagulants were observed to preferentially target different classes of organics in the wastewater.