Combined bioreactor for the treatment of waste water, by means of anaerobic, aerobic and anoxic processes of degradation of organic matter with zone separator system and collection of biogases, scum and sludge

• US 9,758,411 B2
• Filed: 12/19/2012
• Issued: 09/12/2017
• Est. Priority Date: 03/02/2012
• Status: Active Grant

• Current Assignee: Francisco Xavier Valdes Simancas
• Original Assignee: Francisco Xavier Valdes Simancas
• Inventors: Valdes Simancas, Francisco Xavier
• Primary Examiner(s): NORRIS, CLAIRE A
• Application Number:
  US14/379,207
• Publication Number:
  US 20150008169A1
• Time in Patent Office: 1,728 Days
• Field of Search: 210188, 210521, 210802, 96220, 96197, 96356, 96392
• CPC Class Codes: C02F 11/02 Biological treatment
• CPC Class Codes: C02F 2203/002 comprising an initial buffer container
• CPC Class Codes: C02F 2203/006 details of construction, e.g. specially adapted seals, modules, connections
• CPC Class Codes: C02F 2303/12 Prevention of foaming
• CPC Class Codes: C02F 3/082 Rotating biological contactors
• CPC Class Codes: C02F 3/301 Aerobic and anaerobic treatment in the same reactor
• CPC Class Codes: C02F 3/305 characterised by the denitrification
• CPC Class Codes: C02F 3/307 characterised by direct conversion of nitrite to molecular nitrogen, e.g. by using the Anammox process
• CPC Class Codes: Y02E 50/30 Fuel from waste, e.g. synthetic alcohol or diesel
• CPC Class Codes: Y02W 10/10 Biological treatment of water, waste water, or sewage

Abstract

A bioreactor for anaerobic, aerobic and anoxic digestion of organic matter from wastewater, having a bottom anaerobic zone where the wastewater is fed where anaerobic bacteria produces biogas and the sludge produced is deposited on the bottom and subsequently extracted. An anoxic middle zone contains denitrifying bacteria which converts nitrates to nitrogen, and an aerobic zone at the upper part where at least one biological contact rotor is disposed, which degrade organic matter remaining in the water. The growth of nitrifying bacteria converts ammonia nitrogen into nitrites and nitrates. The tank has a plurality of rhomboids for biogas, sludge and scum collection that join together form a intermediate polyhedral separator panel. The rhomboids joined together define conical collectors with connecting nozzles of ducts from a capture and conduction network of biogas and funnel-shaped manifolds with connecting nozzles of ducts that define a capture and conduction network of sludge and scum.

Claims

1. A combined bioreactor for wastewater treatment, through anaerobic, aerobic and anoxic processes of organic matter degradation with zone separator system and biogas, scum and sludge collection, wherein the combined bioreactor comprises a tank divided into an upper aerobic zone, a middle anoxic zone and a lower anaerobic zone wherein, said lower anaerobic zone contains a feed duct where the wastewater to be sanitized enters the tank, and where the action of anaerobic bacteria, contained in said anaerobic zone, degrade organic matter present in said wastewater to produce biogas (CH₄ and CO₂) and a small amount of sludge which settles to the bottom of the lower anaerobic zone and which then is extracted through a perforated pipe located on the bottom of the bioreactor;

said anoxic zone, located between the lower anaerobic zone and upper aerobic zone, comprises water from the anaerobic zone together with a quantity of recirculation water from the aerobic zone, and contains a growth of denitrifying bacteria that convert nitrates from the recirculation stream to gaseous nitrogen in the presence of carbon compounds contained in the wastewater; and

said upper aerobic zone comprises at least one biological contact rotor, wherein said rotor degrades organic matter remaining in the wastewater which passed through the bottom anaerobic and anoxic zones and further wherein-said rotor enables the growth of different types of nitrifying bacteria that convert ammonia nitrogen to nitrites and then to nitrates;

wherein said combined bioreactor further comprises a plurality of substantially rhomboid shaped separators for biogas, sludge and scum collection which when said rhomboid shaped separators are joined together form an intermediate polyhedral separator panel attached and supported on a plurality of intermediate columns and beams implemented in the tank; and

further when said rhomboid shaped separators are joined together said rhomboid shaped separators define a plurality of conical collectors with upper connecting nozzles of ducts forming a biogas and scum capture and conduction network and a plurality of collecting funnels with lower cylindrical connecting nozzles of ducts forming a sludge capture and conduction network.

2. The combined bioreactor for wastewater treatment, through anaerobic, aerobic and anoxic processes of organic matter degradation with zone separator system and biogas, scum and sludge collection, according to claim 1, wherein said intermediate polyhedral separator panel is located at the interface of the anaerobic zone and the anoxic zone;

wherein said separator panel is fabricated from corrosion resistant sheet material having sufficiently stiffness to support the weight of the sludge and the gas floating efforts as would be Fiberglass Reinforced Polyester (FGRP), stainless steel or other material that resists corrosion for at least 50 years.

3. The combined bioreactor for wastewater treatment, through anaerobic, aerobic and anoxic processes of organic matter degradation with zone separator system and biogas, scum and sludge collection, according to claim 1, wherein each conical collector to capture biogas and scum and each sludge collecting funnel of said intermediate polyhedral separator panel, are formed by four substantially rhomboid shaped straight parts comprising respective connecting perimeter flanges wherein clamping means and sealing elements are used to connect the flanges of adjoining substantially rhomboid shaped straight parts to each other at 45 to 60°

inclines respective to the horizontal;

wherein said substantially rhomboid shaped straight parts further comprising a quarter-circle at the upper and bottom corners of each rhomboid shaped straight part, so that when four parts are attached, an upper cylindrical nozzle is formed where it is possible to connect the tubes for collection of biogas and scum floating at the upper part of the intermediate polyhedral separator panel and which leads them to a device responsible for their separation and a lower cylindrical nozzle where it is possible to connect the tubes to collect settled sludge into the anaerobic zone of the tank to continue their digestion.

4. The combined bioreactor for wastewater treatment, through anaerobic, aerobic and anoxic processes of organic matter degradation with zone separator system and biogas, scum and sludge collection, according to claim 1, wherein said rhomboid shaped parts that make up said intermediate polyhedral separator panel are disposed at the opposite end of the lower anaerobic zone where the treated water feed duct is disposed, have openings for water to reach the upper part of the tank, the surface of the openings must have a combined area so that the velocity of the water passing through the openings ranges between 0.05 and 0.15 meters per second;

and wherein said openings are covered at the bottom by a baffle of the same material with a similar slope to that of the intermediate polyhedral separator panel so as to prevent the upward flow of gas bubbles, and simultaneously allows water flow through the anoxic zone without excess water flowing into the next zone.

5. The combined bioreactor for wastewater treatment, through anaerobic, aerobic and anoxic processes of organic matter degradation with zone separator system and biogas, scum and sludge collection, according to claim 4, wherein the height of said intermediate polyhedral separator panel to collect and separate gas, sludge, and scum is between 1.5 and 2 m, at a depth of 5 to 7 m in the tank and the overlap between the intermediate polyhedral separator panel and the baffle is between 10 and 20 cm to prevent the upward flow of gas bubbles.

6. The combined bioreactor for wastewater treatment, through anaerobic, aerobic and anoxic processes of organic matter degradation with zone separator system and biogas, scum and sludge collection, according to claim 1, wherein said plurality of conical collectors of biogas and scum and said plurality of sludge collecting funnels of said intermediate polyhedral separator panel, comprise reinforcing elements disposed below and supported by said intermediate columns and beams.

7. The combined bioreactor for wastewater treatment, through anaerobic, aerobic and anoxic processes of organic matter degradation with zone separator system and biogas, scum and sludge collection, according to claim 1, wherein said perforated pipe is disposed in the lower anaerobic zone of the bioreactor and is distributed along the lower anaerobic zone, being placed at about 10 cm from the bottom of said tank in the lower anaerobic zone, so that it has a collection area by means of holes evenly distributed on the bottom;

wherein a suction force is maintained in said pipe, further wherein said holes have different diameters ranging from 19.05 mm to 38.1 mm (¾

″

to 1½

″

) and wherein the size of said holes located in said perforated pipe are smallest in diameter where the suction force is greatest and with said holes increasing in diameter along said perforated pipe as the suction force in the pipe decreases, so that the suction is uniform along the perforated pipe.

8. The combined bioreactor for wastewater treatment, through anaerobic, aerobic and anoxic processes of organic matter degradation with zone separator system and biogas, scum and sludge collection, according to claim 6, wherein said conical collectors further comprise two pipes, one responsible for collection gas and scum which floats to the upper part of the intermediate polyhedral separator panel and another responsible for transferring the sludge which settles and accumulates in the lower part of the intermediate polyhedral separator panel wherein gas-sludge-scum waste is conducted through said pipes to a gas/sludge/scum external separation device wherein said external separation device extracts biogas from said gas-sludge-scum waste.

9. The combined bioreactor for wastewater treatment, through anaerobic, aerobic and anoxic processes of organic matter degradation with zone separator system and biogas, scum and sludge collection, according to claim 1, wherein said at least one biological contact rotor having a top part and a lower part consists of a polyethylene or polypropylene disc of 5.5 m diameter which rotates about an axis by action of a motor, remaining in contact with air and water from the anoxic zone.

10. The combined bioreactor for wastewater treatment, through anaerobic, aerobic and anoxic processes of organic matter degradation with zone separator system and biogas, scum and sludge collection, according to claim 9, further comprising one or more sludge extraction pipes located in the lower part of at least one biological contact rotor connected to semicircular plates that separate the aerobic zone from the anoxic zone wherein below said at least one biological contact rotor are particularly arranged semicircular plates that separate the aerobic zone from the anoxic zone, where at least one sludge extraction pipe is connected, so that biomass that forms a thin layer on the surface of a biological contact rotor and thereafter becomes detached from the rotor does not accumulate in said plates, but is extracted by means of said sludge extraction pipe and recirculated to the anoxic zone, where a portion of the extracted biomass will be degraded and the remaining portion of said biomass will be settled out on the intermediate polyhedral separator panel located in the anoxic zone.

11. The combined bioreactor for wastewater treatment, through anaerobic, aerobic and anoxic processes of organic matter degradation with zone separator system and biogas, scum and sludge collection, according to claim 1, wherein the combined bioreactor further comprises an adjoining homogenization tank where flow and organic load from wastewater is uniformed prior to its supply to the bioreactor.

12. The combined bioreactor for wastewater treatment, through anaerobic, aerobic and anoxic processes of organic matter degradation with zone separator system and biogas, scum and sludge collection, according to claim 1, wherein the combined bioreactor further comprises a water outlet located in the aerobic zone where the biologic contact rotors are located and a clarifier tank located on the opposite side of the water outlet wherein treated water, after passing through the aerobic zone where biological contact rotors are located, flows into said clarifier tank, further wherein said clarifier tank comprises a chamfered wall bottom to encourage sedimentation of biomass detached from biological contact rotors;

further comprising recirculation ducts at the bottom of said clarifier tank which redirect biomass to the anoxic one.

13. The combined bioreactor for wastewater treatment, through anaerobic, aerobic and anoxic processes of organic matter degradation with zone separator system and biogas, scum and sludge collection, according to claim 12, wherein said clarifier tank further comprises disinfection means that destroys residual microorganisms.

14. The combined bioreactor for wastewater treatment, through anaerobic, aerobic and anoxic processes of organic matter degradation with zone separator system and biogas, scum and sludge collection, according to claim 4, wherein the height of said intermediate polyhedral separator panel to collect and separate gas, sludge, and scum is between 1.5 and 2 m, at a depth of 5 to 7 m in the tank and the overlap between the intermediate polyhedral separator panel and the baffle is between 10 and 20 cm to prevent the upward flow of gas bubbles.

15. The combined bioreactor for wastewater treatment, through anaerobic, aerobic and anoxic processes of organic matter degradation with zone separator system and biogas, scum and sludge collection, according to claim 13, wherein said disinfection means is UV light.

16. The combined bioreactor for wastewater treatment, through anaerobic, aerobic and anoxic processes of organic matter degradation with zone separator system and biogas, scum and sludge collection, according to claim 13, wherein said disinfection means is an ozone unit and/or a chlorination means.