Canonical correspondence analysis (CCA) biplot based on T-RFLP data and measurable variables (operational and environmental) in the pilot-scale wastewater treatment plant.

<p>Arrows indicate the direction and magnitude of measurable variables associated with AOB community structures. Each Circle and associate number represents a different AOB community structure from a specific sampling date. Environmental variables were chosen based on significance (<i>P</i><0.05) calculated from individual CCA results and variation inflation factors calculated during CCA.