Figure 1.

Nitrification performance (mg N L⁻¹ d⁻¹) and nitrogen loss (%), that is, the amount of removed NH₄⁺-N not recovered as NO₂⁻-N or NO₃⁻-N, in the thermophilic bioreactor (50 °C) inoculated with thermophilic nitrifying batch enrichments from compost samples. Average influent NH₄⁺-N and NO₂⁻-N concentrations (mg N L⁻¹, n=±70, over ∼100 days) are presented on top of the figure. The white and black triangles indicate the sampling for high-throughput DNA sequencing and transmission electron microscopy, respectively.