Accumulation and structure of bacterial community during high-strength wastewater treatment using a novel BIFBBR

A novel bubble-induced inverse fluidized bed bioreactor (BIFBBR) was first applied to treat high-strength wastewater. The BIFBBR continuously operated for 207 days, and stably achieved over 98.6 % Chemical Oxygen Demand (COD) removal at an Organic Loading Rate (OLR) of 7.68 kg COD/(m³·d) when successfully realized approx. 97 % Total Nitrogen (TN) reduction. Different particle properties were employed in the BIFBBR to further reveal their effects on the bacterial communities. The dominant phylum of bacterial community enriched in the BIFBBR includes Proteobacteria, Acidobacteria, Bacteroidetes, Firmicutes, and Nitrospirae, with the predominant genus including Thauera, Gemmoactor, Hydrogenophaga, Rhodobacter, Nitrosomonas, etc. The system employed with polyethylene particles coated by activated carbon demonstrated better maintenance of community abundance, diversity, and stability compared to with or without modified surface particles. In addition, it is worth to note that the bacteria in biofilm exhibited significantly greater abundance and diversity than suspended bacteria in liquid.