Apparatus and methods for control of waste treatment processes
View Patent ↗Waste-treatment processes are enhanced through generation and introduction of specific biological populations customized to perform or favor specific tasks either during the main process, for the formation or precipitation of certain biological nutrients, or to accomplish solids formation reduction in a post-treatment process. These bacteria may be grown from specialized mixes of activated sludge and waste influent by exposing these materials to controlled environments (e.g., in an off-line treatment area). They may then be returned to the main process to perform certain tasks such as converting particulate cBOD into soluble cBOD for utilization, to reduce high solids yield organisms by supplementing the population with low yield organisms, to provide biological nutrients or oxygenation assistance, to improve nitrification/denitrification efficiency, or to disfavor filamentous biology such as Norcardia sp.
1. A method of treating a waste stream, the method comprising the steps of:
a. conducting at least a portion of the waste stream to a first treatment vessel for treatment comprising contact with a first biological population having a first population profile;
b. drawing off a portion of the waste stream to an off-line treatment vessel comprising a unitary uncompartmented tank; and
c. controlling the drawn-off portion of the waste stream in the off-line treatment vessel so as to establish, in the drawn-off portion, a second biological population having a second population profile different from the first population profile by sequentially subjecting the entire drawn-off portion within the unitary uncompartmented tank to aerobic conditions followed by anaerobic or anoxic conditions, wherein during the controlling step, there is no flow from the off-line treatment vessel to the first treatment vessel, wherein the step of sequentially subjecting the drawn-off portion to aerobic and anaerobic or anoxic conditions comprises (i) at least one accelerated cycle of achieving a predetermined aeration intensity level followed by reducing oxygen levels to anaerobic or anoxic conditions, and (ii) an extension of at least one accelerated cycle in the waste stream in the first treatment vessel.
2. The method of claim 1 wherein the predetermined aeration intensity level is determined based on the size of an input area for conducting oxygen into the waste stream in the first treatment vessel.
3. The method of claim 1 wherein oxygen levels are reduced by providing an external carbon source to drive loss of oxidation pressure in the first treatment vessel.
4. The method of claim 3 wherein the external carbon source is selected from the group consisting of: raw influent, an unstable mixed liquor generated in the first treatment vessel, and methanol.
5. The method of claim 1 wherein the anoxic conditions are characterized by an ORP level in the drawn-off portion of about 50 mV or Less.
6. The method of claim 1 wherein the controlling step comprises a controlled addition of a further portion of the waste stream into the off-line treatment vessel.
7. The method of claim 1 wherein the controlling step includes allowing settling to produce a decantable volume having a reduced volume and mass of solids.
8. The method of claim 7 wherein the decantable volume comprises a population having a reduced content of biology.
9. The method of claim 1 wherein subjecting the drawn-off portion to aerobic conditions comprises pulsed aeration.
10. The method of claim 1 , wherein the predetermined aeration intensity level comprises an aerobic intensity level sufficient to provide a dissolved oxygen level above about 1 mg/L for a selected period of time.
11. A method of treating a waste stream, the method comprising the steps of:
a. conducting at least a portion of the waste stream to a first treatment vessel for treatment comprising contact with a first biological population having a first population profile;
b. drawing off a portion of the waste stream to an off-line treatment vessel; and
c. controlling the drawn-off portion of the waste stream in the off-line treatment vessel so as to establish, in the drawn-off portion, a second biological population having a second population profile different from the first population profile by sequentially subjecting the drawn-off portion to aerobic conditions followed by anaerobic or anoxic conditions, wherein (i) during the controlling step, there is no flow from the off-line treatment vessel to the first treatment vessel, and (ii) the step of sequentially subjecting the drawn-off portion to aerobic and anaerobic or anoxic conditions comprises at least one accelerated cycle of achieving a high aeration intensity level followed by reducing oxygen levels to anaerobic or anoxic conditions, wherein the high aeration intensity level comprises an aerobic intensity level sufficient to provide at least one of an ORP greater than 100 mV for 24 hours, an ORP greater than 150 mV for 12 hours, or an ORP greater than 200 mV for 4 hours.