Evaluation of the treatment of aquaculture wastewater by a novel hydrocyclone separation and biofilter

Comprehensive research and practical knowledge on the effective integration of different treatment equipment to achieve the complete removal of solid particles and dissolved contaminants of all sizes for maximizing water quality is scarce. In this study, a novel type of hydrocyclone separation and biofilter system (HS-BF) was constructed for the treatment of aquaculture wastewater in South China. The equipment combined hydrodynamic and biological treatment methods, and its performance was evaluated by measuring various water quality parameters. The results indicate that HS-BF effectively removed pollutants, with removal rates of 91.53 ± 2.06 % for NH4+-N, 86.20 ± 7.11 % for NO2−-N, 76.44 ± 9.20 % for NO3−-N, and 84.57 ± 2.88 % for chlorophyll a. The removal rate of total suspended solids reached 83.94 ± 11.56 %. The system also reduced particle size in the effluent water from 190 to 295 nm to 164–190 nm. Bacterial analysis revealed an increase in denitrogenation-related microorganisms such as Acinetobacter and Bacillus with effective filtering of pathogens, such as Staphylococcus, Legionella, and Mycobacterium. The microbial communities in HS-BF exhibited similar characteristics after treatment (P = 0.001), showing a preference for carbon source utilization, primarily carbohydrates and amino acids. This innovative equipment model integrated microbial and physical treatment methods, demonstrating the efficient removal of pollutants from aquaculture wastewater and supporting sustainable industrial development. [Display omitted] •This study designed equipment that combines biological and physical processing.•The equipment can remove solid particles and pathogenic bacteria in wastewater.•The equipment can increase the relative abundance of nitrogen removal bacteria.•New equipment was provided for aquaculture wastewater treatment.