Abstract: The invention pertains to a method for the purification of substrate-containing wastewater in a continuous flow-through aerobic biologically activated sludge reactor B, wherein at least part of biological sludge 6 is conditioned in a selector S under anaerobic or anoxic conditions with at least part of the substrate-containing, to-be-purified wastewater 2, optionally after a pre-treatment step VB of the supplied wastewater 1, such that at least 20 wt % of the sludge in the selector S has a residence time in the selector which is at least 20% greater than the hydraulic residence time of the sludge/water mixture in the selector, after which the thus conditioned sludge/water mixture 3, optionally after an additional anaerobic or anoxic contact step, is fed to the aerobic purification reactor B and subjected to aerobic treatment B, wherein the treated wastewater 4 after aerobic treatment is optionally separated from the sludge by settling NB, flotation or mechanical separation, and wherein (at least a portion of)

Abstract: A process for controlling the aeration rate during the aerobic phase of a wastewater treatment process is disclosed, which comprises: (a) measuring at moment t1 the ammonium concentration [NH4+]1 and nitrogen oxide concentration [NOx]1 in a mixture of wastewater and microbial sludge; (b) determining a nitrogen oxide target concentration [NOx]F1 at the end of the aerobic phase based on at least the current ammonium concentration [NH4+]1 and the current NOx concentration [NOx]1; (c) determining a setpoint [NOx]SP1 based on interpolation between [NOx]1 and [NOx]F1; (d) adjusting the aeration rate to minimise error between [NOx]1 and [NOx]SP1; and (e) repeating steps (a) to (d) at further moments t1. The invention further concerns a process for the treatment of wastewater, using the process.

Abstract: A process for controlling the aeration rate during the aerobic phase of a wastewater treatment process is disclosed, which comprises: (a) measuring at moment t1 the ammonium concentration [NH4+]1 and nitrogen oxide concentration [NOx]1 in a mixture of wastewater and microbial sludge; (b) determining a nitrogen oxide target concentration [NOx]F1 at the end of the aerobic phase based on at least the current ammonium concentration [NH4+]1 and the current NOx concentration [NOx]1; (c) determining a setpoint [NOx]SP1 based on interpolation between [NOx]1 and [NOx]F1; (d) adjusting the aeration rate to minimise error between [NOx]1 and [NOx]SP1; and (e) repeating steps (a) to (d) at further moments t1. The invention further concerns a process for the treatment of wastewater, using the process.