Multi-stage oxic biofilm system for pilot-scale treatment of coking wastewater: Pollutants removal performance, biofilm properties and microbial community

• Published in: Bioresource technology Vol. 411; p. 131271
• Main Authors: Li, Yunlong, Wang, Qingbin, Chen, Hongwei, Song, Chao, Zheng, Yize, Chai, Zimin, Zheng, Maosheng
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.2024
• Subjects: Ammonia-oxidizing microorganisms; Ammonium Compounds; Biodegradation, Environmental; Biofilms; Biomass; Bioreactors; Coke; Comammox; Industrial wastewater treatment; Microbiota; Nitrification; Nitrogen; Phylogenetic analysis; Pilot Projects; Polyurethanes - chemistry; Waste Disposal, Fluid - methods; Wastewater - chemistry; Water Pollutants, Chemical; Water Purification - methods; Phylogenetic analysis; Ammonia-oxidizing microorganisms; Comammox; Industrial wastewater treatment; Nitrification
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2024.131271

[Display omitted] •A multi-stage oxic biofilm system was established for coking wastewater treatment.•Hydrophilic polyurethane carriers enhanced efficient start-up and pollutant removal.•The biofilm showed a dense-to-loose shift shaped by gradient pollutant variation.•Nitrosomonas and Nitrospira’s respective dominance ensured complete nitrification.•The multi-stage configuration maximized the pollutant removal efficiency. A multi-stage oxic biofilm system based on hydrophilic polyurethane foam was established and operated for advanced treatment of coking wastewater, in which distinct gradient variations of pollutants removal, biofilm properties and microbial community in the 5 stages were evaluated. The system rapidly achieved NH4+-N removal efficiency of 97.51 ± 2.29 % within 8 days. The biofilm growing attached on the carriers exhibited high biomass (≥10.29 g/L), which ensured sufficient microbial population. Additionally, the rising extracellular polymeric substance and declining proteins/polysaccharides ratios across stages suggested a dense-to-loose transition in the biofilm’s structure, in response to the varying pollutant concentrations. The dominance of Nitrosomonas cluster in the first 3 stages and Nitrospira lineage in the following 2 stages facilitated the complete depletion of high NH4+-N concentration without NO2--N accumulation. Overall, the distinct biofilm property and community at each stage, shaped by the multi-stage configuration, maximized the pollutants removal efficiency.