| Summary: | Increasing attention has been given to the treatment of livestock and poultry wastewater because of its high ammonium nitrogen (NH<sub>4</sub><sup>+</sup>-N) content and low carbon/nitrogen ratio (C/N). Ceramic filter medium (CFM) and dewatered aluminum sludge (DAS), which are products from cast-off materials, are used as small-scale combined biological filters (CFM-DAS) for wastewater treatment. The high and stale removal efficiency of chemical oxygen demand (COD), NH<sub>4</sub><sup>+</sup>-N, and total nitrogen (TN) in the DAS filter indicate that DAS plays a major role in pollutant removal. Although significant differences are found between the composition of nitrifying bacteria in CFM and DAS, the structures of nitrifying communities are evenly distributed in each layer of CFM or DAS irrespective of the running time. Microbial compositions are attributed to the comprehensive effect of various environmental factors such as pH and TN at effluents. In the DAS, <i>Nitrosospira</i> shows significant negative correlation with the concentrations of NH<sub>4</sub><sup>+</sup>-N in effluents, whereas it has positive correlation with NO<sub>3</sub><sup>−</sup>-N, and <i>Nitrososphaera</i> has a significant negative correlation with NO<sub>3</sub><sup>−</sup>-N in effluents. Pearson correlation test reveals that certain genera may be used in estimating or predicting NH<sub>4</sub><sup>+</sup>-N consumption and NO<sub>3</sub><sup>−</sup>-N accumulation in CFM-DAS for treating sewage with a high NH<sub>4</sub><sup>+</sup>-N content.
|
|---|
