Effective Treatment of Phenol Containing Coking Wastewater Via Photogranules: Performance, Microbial Community, and Removal Pathways

Abstract

The high concentration of phenol present in coking wastewater represents a significant limitation to the applicability of biological methods. The objective of this study was to investigate the efficacy of photogranules in treating phenol-containing coking wastewater and to identify the associated removal pathways. The findings indicated that the photogranules have the potential to be employed in the treatment of phenol-containing wastewater, exhibiting excellent settling capabilities and a compact structure. The reactor treated with phenol was dominated by Diaphorobacter, with Comamonas and unclassified f-Enterobacteriaceae as the main denitrifying genera. Phenol will eventually be completely degraded, providing material and energy for microbial life activities. Ultimately, the energy accounting and carbon emission analysis revealed that the photogranules can achieve approximately 2.67 kWh of electrical energy recovery and achieve carbon neutrality. The findings of this study will provide a novel insight into the potential application of biological treatment of coking wastewater.

Keywords: Photogranules, Coking wastewater, Nitrogen removal and phenol removal, Phenol metabolic pathway, Carbon neutrality, Electrical energy recovery