Emerging trends in sequencing batch reactor operation and enhancement for improved phenol removal

Phenol and its derivatives, commonly found in industrial processes as raw materials, intermediates, or final products, pose a considerable environmental risk due to their toxic nature and widespread presence in industrial effluents. This article offers an in-depth analysis of operational factors and advanced strategies for the aerobic breakdown of phenol in sequencing batch reactors (SBRs). It highlights several innovative techniques that have been developed to enhance the efficiency of phenol biodegradation in SBR systems, including the use of adsorbents within the reaction environment and the integration of hybrid treatment methods. These improvements have significantly increased the efficiency of phenol removal and have strengthened the microbial communities' ability to withstand high phenol levels, up to 1000 mg/L, typically found in wastewater streams. Additionally, the article investigates the application of aerobic granulation technology in SBRs for phenol treatment, showcasing its exceptional capability to manage sudden spikes in phenol concentrations, reaching as high as 2000 mg/L. Systems employing aerobic granulation have been shown to boost the microbial population's resilience to sudden phenol influxes and considerably reduce the sludge volume index (SVI), thereby enhancing the sedimentation of microbial aggregates and improving the overall phenol biodegradation process.