Method and a system for out-competing glycogen-accumulating organisms in a substance
A method and a substance treatment system for reducing a ratio of Glycogen-Accumulating Organisms relative to the total amount of Glycogen-Accumulating Organisms and Polyphosphate-Accumulating Organisms in a substance. A controller for controlling a waste water treatment system in accordance with the method. Use of the method according to control a waste water treatment system in accordance with the method.
1. A method of reducing a ratio of Glycogen-Accumulating Organisms relative to a total amount of Glycogen-Accumulating Organisms and Polyphosphate-Accumulating Organisms in a substance comprising waste water and/or activated sludge, the method comprising the steps of:
providing the substance in an anaerobic environment;
determining the substance temperature;
determining a predetermined level of the ratio of Glycogen-Accumulating Organisms relative to a total amount of Glycogen-Accumulating Organisms and Polyphosphate-Accumulating Organisms in the substance;
providing a controller adapted to control the reduction of Glycogen-Accumulating Organisms relative to the total amount of Glycogen-Accumulating Organisms and Polyphosphate-Accumulating Organisms;
determining by use of the controller a first predetermined period of time as a function of the substance temperature such that the first predetermined period of time corresponds to the ratio being below the predetermined level; and
controlling the reduction by maintaining the substance in the anaerobic environment at the substance temperature for the first predetermined period of time, until the ratio of Glycogen-Accumulating Organisms relative to a total amount of Glycogen-Accumulating Organisms and Polyphosphate-Accumulating Organisms in the substance, is below the predetermined level.
2. A method according to claim 1 , wherein the first predetermined period of time is above 10 hours.
3. A method according to claim 1 , wherein the ratio of Glycogen-Accumulating Organisms relative to a total amount of Glycogen-Accumulating Organisms and Polyphosphate-Accumulating Organisms in a substance is below 10 percent.
4. A method according to claim 1 , further comprising the step of:
subsequently subjecting the substance to an anoxic and/or an aerobic environment.
5. A method according to claim 1 , further comprising the step of:
subjecting the substance to an aerobic environment for a second predetermined period of time.
6. A method according to claim 1 , further comprising the step of:
re-circulating at least a part of the substance to the anaerobic environment.
7. A method according to claim 1 , further comprising the step of:
increasing the dry solids content prior to the step of re-circulating.
8. A method according to claim 1 , wherein the first predetermined period of time decreases with an increasing temperature.
9. A method according to claim 1 , wherein the first predetermined period of time is in the range 18-48 hours, when the substance temperature is in the range 5-20 degrees Celsius.
10. A method according to claim 1 , wherein the first predetermined period of time is in the range 12-36, hours when the substance temperature is in the range 15-30 degrees Celsius.
11. A method according to claim 1 , wherein the first predetermined period of time is in the range 10-30 hours, when the substance temperature is in the range 25-35 degrees Celsius.
12. A method according to claim 1 , wherein the Glycogen-Accumulating Organisms comprises: Candidatus-Competibacter-phosphatis-related bacteria and Defluviicoccus - vanus -related bacteria.
13. A method according to claim 1 , wherein the Polyphosphate-Accumulating Organisms comprises Candidatus Accumulibacter phosphatis related bacteria.
14. A substance treatment system for reducing a ratio of Glycogen-Accumulating Organisms relative to a total amount of Glycogen-Accumulating Organisms and Polyphosphate-Accumulating Organisms in a substance containing waste water and/or activated sludge, the substance treatment plant and/or system comprising:
an anaerobic compartment for accommodating the substance in an anaerobic environment during treatment; and
a controller having a predetermined level of Glycogen-Accumulating Organisms relative to a total amount of Glycogen-Accumulating Organisms and Polyphosphate-Accumulating Organisms and being adapted to determine a temperature of the substance; and to calculate a first predetermined period of time as a function of the substance temperature; the controller further being adapted to maintain the substance in the anaerobic environment at a substance temperature for the first predetermined period of time, until the ratio of Glycogen-Accumulating Organisms relative to a total amount of Glycogen-Accumulating Organisms and Polyphosphate-Accumulating Organisms in the substance, is below the predetermined level.