Removing ammonium nitrogen from wastewater during biological treatment, pulsates wastewater at natural frequency of oxygen bubbles or particles

摘要

Wastewater containing ammonium nitrogen, i.e. nitrogen in the form of ammonia, is subjected to pulsation. The pulse frequency is tuned to the natural frequency of oxygen gas bubbles supplied for biological treatment. Alternatively it is tuned to the frequency of particles contained in the activated sludge plant, which are susceptible to oscillation. Pulses are applied using a pulsed gas flow, pulsators, non-uniformly operating pumps, or short term pipe flow interruptions. Alternatively a magnetic field is used, with alternating modulation. Magnetic pulses are imposed on the wastewater being treated, through a pipeline carrying the flow, which is made from a suitable non-magnetic material. The waste water is treated at a pH value between 7.5 and 8.5 and at temperatures of 20-30[deg] C.