Performance of bio-nest by modified basalt fiber carriers on the enhanced remediation of low-carbon and -nitrogen urban black-smelling water

Biological contact oxidation reactors employing modified basalt fiber (MBF) were constructed to systematically investigate the impact of various hydraulic retention times (HRTs) and aeration durations on nitrogen and phosphorus removal in low carbon and polluted river water. The experimental findings underscored that configuring the HRT to 36 h and maintaining an aeration ratio of 1:2 yielded the most favorable outcomes for the removal of COD, NH4+ -N, total nitrogen (TN), and TP from synthetic low carbon, source-polluted river water. Detailed microbial sequencing elucidated the predominant bacterial phylum within the MBF reactor, identified as Proteobacteria. The dominant genera encompassed Pseudomonas, Aeromonas, and SM1A02. This microbial composition, marked by a high abundance of denitrifying genera, corroborated the robust denitrification capacity exhibited by the MBF reactors. The orchestrated combination of optimal operational parameters and the prevalence of key microbial taxa substantiate the efficiency of MBF reactors in effectively mitigating nitrogen and phosphorus in low carbon source river water.