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NO-20240963-A1 - Continuous flow enhanced cleaning reactor apparatus and method

NO20240963A1NO 20240963 A1NO20240963 A1NO 20240963A1NO-20240963-A1

Inventors

  • DZIHORA YULIIA
  • SILJUDALEN JON GREGAR
  • SAVVA ILYA MARIO
  • WANG SHUAI

Assignees

  • BIOWATER TECH AS

Dates

Publication Date
20260324
Application Date
20240923
Priority Date
20240923

Claims (15)

  1. 1. P ATENT C LAIMS 1. A biological wastewater treatment apparatus of the continuous flow type having an operational state, wherein the operational state comprises: a continuous enhanced cleaning state; or an intermittent enhanced cleaning state comprising intermittent noncleaning periods and intermittent cleaning periods, the biological wastewater treatment apparatus comprising: a continuous flow cleaning reactor comprising: a constant liquid volume throughout the operational state of the continuous flow cleaning reactor; a mass of carrier elements, said mass of carrier elements having a constant degree of filling of 70% or more of the reactor volume; and an enhanced cleaning unit; at least one inlet fluid conduit fluidly connected to the continuous flow reactor for continuous inflow of influent containing contaminated water into the continuous flow reactor; and at least one outlet fluid conduit fluidly connected to the continuous flow reactor for continuous outflow of treated effluent comprising sheared biomass; wherein the enhanced cleaning unit is configured to eject a fluid at the mass of carrier elements when the apparatus is in the continuous enhanced cleaning state or the intermittent cleaning periods; and wherein the degree of filling creates a plug flow pattern of wastewater through the reactor when the apparatus is in the operational state.
  2. 2. The apparatus of claim 1, wherein the degree of filling for the carrier elements constitutes an amount in the range of 75% to 90% of the reactor volume.
  3. 3. The apparatus of claim 1 or claim 2, wherein the enhanced cleaning unit is configured to eject a fluid at the mass of carrier elements at a predetermined pulse frequency and flow rate.
  4. 4. The apparatus of claim 3, wherein the enhanced cleaning unit is configured to eject a fluid at the mass of carrier elements at a predetermined frequency and flow rate suitable for providing a predetermined shearing efficacy of the carrier elements, said shearing efficacy for maintaining a layer of biofilm at 1 mm or less.
  5. 5. The apparatus of claim 3, wherein, in the continuous enhanced cleaning state or the intermittent cleaning periods, the enhanced cleaning unit has a predetermined pulse frequency of fluid ejection.
  6. 6. The apparatus of any preceding claim, wherein the apparatus is configured to switch between the intermittent non-cleaning periods and the intermittent cleaning periods after a predetermined duration.
  7. 7. The apparatus of any preceding claim, wherein the enhanced cleaning unit is an array of liquid jets.
  8. 8. The apparatus of any of claims 1 to 6, wherein the enhanced cleaning unit is an array of air jets.
  9. 9. The apparatus of any preceding claim, wherein the enhanced cleaning unit is positioned along the reactor floor and configured to release air or water bubbles upwards through the reactor.
  10. 10. The apparatus of any preceding claim, further comprising a sieve aligned with the outlet pipe, wherein the enhanced cleaning unit facilitates cleaning of the sieve.
  11. 11. A continuous flow method for biological purification of water, comprising: transporting water containing substrate to be removed into a reactor through at least one inlet fluid conduit; transporting the water and substrate through a mass of carrier elements, said mass of carrier elements having a constant degree of filling of 70% or more of the reactor volume; wherein the constant degree of filling of the carrier elements restricts movement of the carrier elements throughout operation and urges the wastewater to move through the reactor in a plug flow pattern; transporting the treated water to at least one outlet fluid conduit; continuously or intermittently cleaning the carrier elements by ejecting fluid from an enhanced cleaning unit disposed inside the reactor; and maintaining a constant liquid volume in the reactor throughout operation.
  12. 12. The method of claim 11, wherein the constant degree of filling of said mass of carrier elements is in the range of 75% to 90% of the reactor volume.
  13. 13. The method of claim 11 or 12, wherein ejecting fluid from an enhanced cleaning unit disposed inside the reactor comprises releasing water or air bubbles upwards through the reactor from the enhanced cleaning unit positioned along the reactor floor.
  14. 14. The method of any of claims 11 to 13, further comprising ejecting fluid from an enhanced cleaning unit at a predetermined pulse frequency and flow rate.
  15. 15. The method of claim 14, further comprising selecting a pulse frequency and flow rate to achieve a shearing efficacy of the carrier elements suitable for maintaining a layer of biofilm at 1 mm or less.

Description

[0001] CONTINUOUS FLOW ENHANCED CLEANING REACTOR APPARATUS AND [0002] METHOD [0004] Background [0006] The present invention relates to biofilm reactors. Biofilm reactors may be employed to treat municipal wastewater such as sewage and other municipal wastewater streams, industrial wastewater, and can also be employed for removal of nutrients like nitrogen and phosphorus. A biofilm reactor is a type of bioreactor used in wastewater treatment where microorganisms grow on surfaces to form a biofilm in order to degrade pollutants. Biofilm reactors employ carriers to provide surfaces for biofilm formation. These can include plastic media, sand, gravel, or specially designed biofilm carriers with high surface areas. The biofilm is an aggregation of microorganisms growing on a solid surface. [0008] Types of biofilm reactors include trickling filters and Moving Bed Biofilm Reactors (MBBRs). In trickling fluid biofilm reactors, wastewater trickles over a bed of media where biofilm grows, allowing microorganisms to degrade organic matter as the water flows through. In moving bed biofilm reactors, free-moving biofilm carriers circulate in the wastewater. In these types of biofilm reactors, regular monitoring and control of biofilm thickness are necessary to prevent clogging and ensure efficient treatment. [0010] One type of biofilm reactor for controlling biofilm thickness is a Continuous Flow Intermittent Cleaning (CFIC) reactor. In a CFIC reactor, wastewater flows continuously through the reactor, allowing for the consistent treatment of incoming wastewater. This continuous flow ensures that the process is ongoing and efficient. However, cleaning of the reactor or the biofilm is done periodically rather than continuously. This intermittent cleaning helps in maintaining the efficiency of the biofilm by preventing excessive buildup and clogging without disrupting the treatment process. [0011] CFIC reactors have advantages compared to other types of wastewater treatment systems since they generally consume less energy. This is because biofilm systems are typically low-energy systems and often require less space compared to conventional wastewater treatment methods like activated sludge systems. [0013] A particular known CFIC reactor is comprised of a biofilm process where the growth surface for micro-organisms consists of carrier elements that, in normal operation, are packed so closely that they cannot move freely and have no, or a hindered, movement. The degree of filling of the carrier elements at normal operation constitutes an amount corresponding to 70% to 100% of the reactor liquid volume. During the cleaning phase, however, the carrier elements are fluidised, between each time excess sludge is removed. The carrier elements are fluidised in that the water level in the reactor is temporarily increased so that the degree of filling of the carrier elements becomes less, such as less than 70% of the reactor liquid volume. Turbulence in the reactor tears an amount of excess sludge off the carrier elements and sedimented sludge is suspended. Inlet water is led into the reactor through one or more inlets and thus brings sludge out of the reactor through one or more outlets. After the cleaning phase, the water level in the reactor is reduced again so that the degree of filling for the carrier elements returns to that during normal operation. [0015] Disadvantages of the above-described CFIC reactor system are that the system requires a more complex arrangement with multiple outlets, as well as requiring hydraulic complexity between cleaning and non-cleaning states. [0017] It is an object of the invention to provide a method and system for continuous processing of wastewater which addresses problems with the above-described known systems and methods. [0018] Summary of the Invention [0020] According to a first aspect of the invention, there is provided a biological wastewater treatment apparatus of the continuous flow type having an operational state, wherein the operational state comprises: a continuous enhanced cleaning state; or an intermittent enhanced cleaning state comprising intermittent noncleaning periods and intermittent cleaning periods, the biological wastewater treatment apparatus comprising: a continuous flow cleaning reactor comprising: a constant liquid volume throughout the operational state of the continuous flow cleaning reactor; a mass of carrier elements, said mass of carrier elements having a constant degree of filling of 70% or more of the reactor volume; and an enhanced cleaning unit; at least one inlet fluid conduit fluidly connected to the continuous flow reactor for continuous inflow of influent containing contaminated water into the continuous flow reactor; and at least one outlet fluid conduit fluidly connected to the continuous flow reactor for continuous outflow of treated effluent comprising sheared biomass; wherein the enhanced cleaning unit is configured