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EP1086051A1 - Procede et systeme de traitement des eaux usees d'un etang aere - Google Patents

Procede et systeme de traitement des eaux usees d'un etang aere

Info

Publication number
EP1086051A1
EP1086051A1 EP19990921808 EP99921808A EP1086051A1 EP 1086051 A1 EP1086051 A1 EP 1086051A1 EP 19990921808 EP19990921808 EP 19990921808 EP 99921808 A EP99921808 A EP 99921808A EP 1086051 A1 EP1086051 A1 EP 1086051A1
Authority
EP
European Patent Office
Prior art keywords
pond
biomedia
aerated
sedimentation
submerged
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP19990921808
Other languages
German (de)
English (en)
Inventor
Clifford A. Merritt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Owens Corning
Original Assignee
Owens Corning
Owens Corning Fiberglas Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Owens Corning, Owens Corning Fiberglas Corp filed Critical Owens Corning
Publication of EP1086051A1 publication Critical patent/EP1086051A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00—Biological treatment of water, waste water, or sewage
    • C02F3/02—Aerobic processes
    • C02F3/10—Packings; Fillings; Grids
    • C02F3/101—Arranged-type packing, e.g. stacks, arrays
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
    • E04H4/00—Swimming or splash baths or pools
    • E04H4/06—Safety devices; Coverings for baths
    • E04H4/08—Coverings consisting of rigid elements, e.g. coverings composed of separate or connected elements
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00—Biological treatment of water, waste water, or sewage
    • C02F3/02—Aerobic processes
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00—Biological treatment of water, waste water, or sewage
    • C02F3/02—Aerobic processes
    • C02F3/06—Aerobic processes using submerged filters
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00—Biological treatment of water, waste water, or sewage
    • C02F3/02—Aerobic processes
    • C02F3/10—Packings; Fillings; Grids
    • C02F3/105—Characterized by the chemical composition
    • C02F3/108—Immobilising gels, polymers or the like
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00—Biological treatment of water, waste water, or sewage
    • C02F3/02—Aerobic processes
    • C02F3/10—Packings; Fillings; Grids
    • C02F3/109—Characterized by the shape
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F7/00—Aeration of stretches of water
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/10—Inorganic compounds
    • C02F2101/16—Nitrogen compounds, e.g. ammonia
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/007—Contaminated open waterways, rivers, lakes or ponds
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2203/00—Apparatus and plants for the biological treatment of water, waste water or sewage
    • C02F2203/006—Apparatus and plants for the biological treatment of water, waste water or sewage details of construction, e.g. specially adapted seals, modules, connections
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W10/00—Technologies for wastewater treatment
    • Y02W10/10—Biological treatment of water, waste water, or sewage
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W10/00—Technologies for wastewater treatment
    • Y02W10/30—Wastewater or sewage treatment systems using renewable energies
    • Y02W10/37—Wastewater or sewage treatment systems using renewable energies using solar energy

Definitions

  • the present invention relates to the treatment of sanitary and non-sanitary wastewater for return to the environment. More particularly, the present invention relates to a four-pond wastewater treatment system and process in which biological oxygen demand, suspended solids, and ammonia in the effluent are controlled within acceptable limits. Suspended solids are controlled in part by limiting the growth of algae using an opaque modular floating cover on the surface of the aerated, sedimentation, and polishing ponds. Nitrification of ammonia is enhanced in the aerated pond using submerged attached growth biomedia for supporting nitrifier microorganisms below the modular cover.
  • cold climate I mean locations characterized by average ambient temperatures that are sufficiently low for at least a portion of the year that an ammonia discharge concentration of 2 - 10 mg/1, preferably 5 - 10 mg/1, is not substantially harmful to aquatic flora and fauna species populating said aquatic environment.
  • the invention is a process for treating sanitary and non-sanitary wastewater in a four-pond system in which wastewater feed flows, in order, through an aerated equalization pond, an aeration pond, a sedimentation pond, and a polishing pond.
  • a plurality of floating modular casings lashed together cover substantially the entire surface of the aerated pond to block out sunlight and thereby significantly reduce if not prevent the growth of algae in the aeration pond.
  • Pass-through openings in the cover accommodate preferably a pair of spaced-apart flotation style aerators.
  • the floating modular casings cover substantially all of the sedimentation pond and polishing pond, as well.
  • attached growth biomedia is submerged within the aeration pond.
  • Fig. 1 is a schematic of the four-pond wastewater treatment process of the present invention.
  • Fig. 2 is a perspective view of several prior art floating casings lashed together by fasteners and a fastening cable.
  • Fig. 3 is a detail elevation view of the prior art system of Fig. 2 for fastening floating casings together.
  • Fig. 4 is a perspective cutaway view of an alternative casing fastening system.
  • Fig. 5 is a diagram of a prior art biomedia.
  • raw wastewater 1 is treated in a four- pond wastewater treatment process for return to the environment.
  • the raw wastewater may contain sanitary and non-sanitary or industrial components, such as cooling system blowdown and research laboratory chemical waste.
  • Wastewater feed 2 is fed first to the equalization pond 10 then to the aeration pond 20, sedimentation pond 30, and polishing pond 40 before it is discharged as process effluent 8 to a natural aquatic environment, such as a river.
  • Each of the treatment ponds (10, 20, 30, 40) will preferably have generally sloping sidewalls and a substantially flat central disposed pond bottom.
  • the ponds are clay-lined. While the shape of each pond is not critical, they will each be generally regular in shape.
  • the equalization pond, aeration pond, and sedimentation pond may be rectangular in shape while the polishing tank may be triangular in shape.
  • the size and depth of each pond will be determined based on factors such as the nominal flow capacity of the system.
  • the nominal flow capacity may be, for example, 0.15 MGD (million gallon per day).
  • the equalization pond will vary in volume, from about 50, 000 to about 120,000 gal. for accumulation and mixing of wastewater feed 2 so that perturbations in hydraulic load and variations in composition or biochemical oxygen demand (BOD) may be dampened to prevent these variations from affecting the aeration pond.
  • the substantially flat central bottom 21 of the aeration pond may be approximately 30 ft x 100 ft, for example, and have a nominal depth of 10 feet. Specific size or shape dimensions of the various ponds should not be viewed as limiting the scope of the claimed invention.
  • Both the equalization pond and aeration pond will include preferably a pair of spaced apart floating aerators 22, such as aspirating jet type aerators, placed generally above the diagonal corners of the substantially flat central pond bottoms.
  • Raw wastewater 1 may contain a sufficiently high level of chlorine, such as 0.05 - 0.1 mg/1 or higher, as to at least inhibit if not prevent altogether the growth of the desired carbonaceous and nitrification microorganisms in the aeration pond.
  • the equalization pond is dechlorinated, such as by the addition of sodium bisulfate, to reduce chlorine levels below the point at which microorganism growth in the aeration pond would be adversely affected.
  • the addition of sodium bisulfate 3 may be used to reduce the chlorine concentration in the equalization pond to 0.05 mg/1 or less, preferably to about 0.01 mg/1 or less.
  • the dechlorinating agent may be added to the equalization pond in any convenient manner, such as by addition to the suction of the lift pump transferring wastewater from the equalization pond to the aeration pond with a portion of the pump discharge being recycled back to the equalization pond (not shown). The remaining portion of the lift pump discharge carries equalization pond effluent 4 to the aeration pond.
  • one or more frames 23 supporting attached growth biomedia are placed on the central flat pond bottom 21 about mid- way between the aeration pond aerators.
  • the frames are made from an inert lightweight material, such as aluminum or polyvinyl chloride.
  • the frames may be virtually any size, so long as the biomedia are submerged and not placed so close to the aerators to be disrupted or jostled by the hydraulic currents.
  • four 10 ft. x 10 ft. aluminum frames may rest on a 30 ft x l00 ft central bottom portion of the clay liner mid- way between two aerators positioned above two diagonal corners of the pond bottom.
  • Aeration pond 20 is schematically shown in Fig. 1 which is not drawn to scale.
  • the frames have channels and foot pads for stability (not shown).
  • the frames support racks of attached growth biomedia.
  • biomedia A variety of different types of biomedia are known, for example, batt media as described in U.S. Pat. No.
  • a preferred type is fiber loop type biomedia 70, as shown in Fig. 5, including fibers 71 attached to central strand 72.
  • a most preferred type is RINGLACETM brand attached growth biomedia, manufactured by Ringlace Products, Inc., Portland, Oregon
  • the RINGLACETM biomedia is made of 100 micron diameter polyvinylidene chloride fibers woven into strands.
  • the biomedia includes flexible loops extending from the strands. Nitrif ⁇ er microorganisms are supported on the loops.
  • the strands define an open spacing approximately three-inches across which allows for free-flow of oxygenated wastewater through the frames
  • the growth of algae is substantially reduced and virtually prevented altogether by blocking sunlight to one or more of the aeration, sedimentation, and polishing ponds.
  • sunlight is blocked from all three ponds. Any desired pond is deprived of natural sunlight by a number of possible means.
  • Sunlight may be blocked by floating on its surface an opaque cover 80 assembled by lashing together a plurality of floating modular casings 81, 82, 83.
  • the cover system is available from Industrial Environmental Concepts, Inc., of Minneapolis, Minnesota. Sunlight may also be blocked by semi- permeable fabrics suspended above the surface of the pond. Preferred fabrics will block and/or filter the sunlight by varying factors such as the weave, thread density, color, and polarization components.
  • the means for shading the pond allows for regulation of the amount of shading by changing the cover or retracting the cover such that not all of the pond surface is covered.
  • each casing is generally rectangular in shape and up to about 8 feet wide and 40 feet long. As shown in Fig. 3, each casing is constructed from an upper membrane 84 and lower membrane 85 that is heat fusion welded together at a seam 85 along a casing edge 86.
  • the upper and lower membranes sealingly encase a buoyant 2-inch thick foam core to provide floatation for the casing.
  • the foam is expanded polystyrene foam.
  • the cores are most preferably FORMULAR® 250 brand expanded polystyrene foam available from Owens Corning Corporation.
  • the membranes are made from penetration- resistant 40-mil thick high density polyethylene.
  • the casing edges 86 of adjacent casings overlie each other and are fastened together by a fastening system to form an overlap joint.
  • Two such fastening systems are shown in Fig. 3 - Fig. 4.
  • the fastening system in Fig. 3 includes a series of spaced-apart holes 88 along each peripheral edge of the casings.
  • a fastening member 90 is inserted from underneath each pair of aligned holes until a band retaining member 91 on the fastening member 90 prevents further passage of the fastening member through the holes 88.
  • the fastening member includes a circular band 92 of membrane material at one end of which the retaining member is attached.
  • the retaining member 91 is designed to be pulled up against the underside of the overlapped casing edges 86 thereby preventing removal of the band entirely through the holes 88.
  • the cable is threaded through all bands in an aligned row of casing holes and anchored at each end by concrete fixtures 110 (see Fig. 4) beyond the perimeter of the pond.
  • the cables allow the casings to rise and fall with minor changes in fluid level while securely holding down the casings in the wind.
  • the edge holes may be spaced at regular intervals, say, about 3 feet apart from one another.
  • Each membrane edge is intentionally not otherwise securely attached to an adjacent membrane edge so that the pond surface may absorb oxygen and vent gasses through the overlap joints, rain water and snow melt may drain into the pond through the overlap joints, and water does not collect on the surface of the casings as to submerge the entire casings below the liquid surface. Accordingly, the pond can "breathe" through the overlapping j oints .
  • the casings are substantially opaque to sunlight.
  • the cover as a whole blocks substantially all light energy that would otherwise reach the pond surface during daylight hours.
  • the floating modular cover significantly limits and preferably substantially prevents the growth of photosynthetic algae in the ponds equipped with the cover system.
  • the casings may have thermal insulation R values of 8 - 30 depending on the number of polystyrene cores encased by the membranes.
  • the casings may have an R value of 8 - 12 for at least partially thermally insulating the pond liquid from the ambient atmospheric conditions.
  • the aeration pond is aerated notwithstanding the presence of the floating cover covering preferably the entire pond surface.
  • the cover may include pass-through openings 120 (Fig. 1) in the cover structure to accommodate placement of the floating aerators in the openings.
  • the process stream flows from the aeration pond to the sedimentation pond and then from the sedimentation pond to the polishing pond.
  • One or preferably both of the sedimentation and polishing ponds also include a substantially opaque cover covering substantially the entire pond surface constructed from floating modular casings as described above with respect to the aeration pond. No pass-throughs are necessary, however, since the sedimentation and polishing ponds are not aerated.
  • the polishing pond is disinfected by any suitable method.
  • chlorination of the polishing tank is one possible approach.
  • the sedimentation pond effluent is irradiated by an artificial source of ultraviolet radiation 60 to such an extent as to effectively disinfect the polishing tank effluent 8.
  • the polishing pond effluent is discharged to an aquatic environment such as a stream, river, marsh, pond, bay, ocean, or other natural body.
  • the present invention is especially well suited and beneficial for use in colder climates.
  • Colder climates include locations characterized by average ambient temperatures that are sufficiently low for at least a portion of the year that an ammonia discharge concentration of 2 - 10 mg/1, preferably 5 - 10 mg/1 is not substantially harmful to aquatic flora and fauna species populating said aquatic environment.
  • Biochemical oxygen demand can be reduced to below about 10 mg/1, preferably below about 5 mg/1, and more preferably to about 3 mg/1.
  • Suspended solids may be reduced below about 12 mg/1, preferably below about 10 mg/1, and more preferably below about 6 mg/1.
  • Ammonia can be reduced to below about 2 mg/1, preferably about 1 mg/1, and more preferably below about 1 mg/1.
  • pH can be controlled in the range of about 6.5 to about 9, preferably in the range of about 7 to about 8.5, and more preferably in the range of about 7 to about 8, without the addition of neutralizing agents such as carbon dioxide or strong acids to the wastewater being processed.
  • Chlorine can be controlled below about 0.02 mg/1 and preferably below about 0.01 mg/1.
  • the result of the present invention is a wastewater treatment process discharge stream having unexpectedly improved performance characteristics.
  • a four-pond wastewater treatment facility rated for 0.15 MGD wastewater flowrate was constructed. Floating modular covers were installed on the sedimentation pond and polishing pond, but not on the aeration pond or equalization pond. Submerged attached growth biomedia was not used. Dechlorination of the equalization pond was conducted. The wastewater flow rate was about 0.08 MGD, and the process effluent was characterized as reported in Table I. In Table I, "SS" refers to "suspended solids.”
  • Example III The same conditions as stated in Example I, except attached growth biomedia was submerged in the aeration pond as described above.
  • the wastewater flow rate was about 0.04 MGD, and the process effluent was characterized as reported in Table I.
  • Example III
  • Example II The same conditions as in Example II, but floating modular covers were also installed on the aeration pond.
  • the wastewater flow rate was about 0.04 MGD, and the process effluent was characterized as reported in Table I.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Hydrology & Water Resources (AREA)
  • Water Supply & Treatment (AREA)
  • Organic Chemistry (AREA)
  • Biodiversity & Conservation Biology (AREA)
  • Microbiology (AREA)
  • Architecture (AREA)
  • Structural Engineering (AREA)
  • Civil Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Biological Treatment Of Waste Water (AREA)
  • Aeration Devices For Treatment Of Activated Polluted Sludge (AREA)

Abstract

On décrit un procédé de traitement des eaux usées à quatre étangs qui permet de réguler les algues et l'ammoniac dans l'écoulement d'effluent. On fait flotter plusieurs couvertures modulaires opaques (80, 81, 82, 83) sur une partie ou sur la totalité de la surface de l'étang d'aération, de l'étang de sédimentation et de l'étang de polissage pour bloquer la lumière du soleil et réguler ainsi la croissance des algues et des solides en suspension. Un milieu biologique de croissance associé est plongé dans l'étang d'aération pour activer la nitrification de l'ammoniac.
EP19990921808 1998-06-17 1999-05-07 Procede et systeme de traitement des eaux usees d'un etang aere Withdrawn EP1086051A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US8959098P 1998-06-17 1998-06-17
US89590P 1998-06-17
PCT/US1999/010139 WO1999065829A1 (fr) 1998-06-17 1999-05-07 Procede et systeme de traitement des eaux usees d'un etang aere

Publications (1)

Publication Number Publication Date
EP1086051A1 true EP1086051A1 (fr) 2001-03-28

Family

ID=22218484

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19990921808 Withdrawn EP1086051A1 (fr) 1998-06-17 1999-05-07 Procede et systeme de traitement des eaux usees d'un etang aere

Country Status (6)

Country Link
EP (1) EP1086051A1 (fr)
JP (1) JP2002518163A (fr)
KR (1) KR20010052878A (fr)
AU (1) AU3892199A (fr)
CA (1) CA2335697A1 (fr)
WO (1) WO1999065829A1 (fr)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2885630B1 (fr) * 2005-05-10 2008-09-26 Trema France Soc Par Actions S Dispositif de fermeture de couverture de piscine, bassin, plan d'eau ou analogue
WO2016061665A1 (fr) 2014-10-20 2016-04-28 Bionest Technologies Inc. Réacteur de traitement d'eau
CN107473383B (zh) * 2016-06-07 2020-11-10 中国石油化工股份有限公司 一种处理氨氮废水的装置及方法

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2540284C3 (de) * 1974-04-18 1979-10-11 Kurt 8391 Kellberg Leistner Einrichtung zur biologischen Reinigung von Abwasser in einem Gewässer, wie Teich o.dgl
GB1574922A (en) * 1976-09-24 1980-09-10 Niigata Engineering Co Ltd Method and unit for wastewater treatment by microorganisms
US4209388A (en) * 1978-11-06 1980-06-24 Defraites Arthur A Method and apparatus for treating sewage
US5256281A (en) * 1991-06-20 1993-10-26 The Lemna Corporation Baffle system for anaerobic sewage treatment pond
WO1994006720A1 (fr) * 1992-09-16 1994-03-31 The Lemna Corporation Reacteur de nitrification flottant utilise dans un bassin de traitement
US5400549A (en) * 1993-10-22 1995-03-28 Morgan; William D. Insulated removable pond cover
US5736047A (en) * 1995-02-28 1998-04-07 Lemna Corporation Hybrid biological nutrient removal system
US5771716A (en) * 1995-09-18 1998-06-30 Schlussel; Edward Warp-knitted loop net fabric
US5861095A (en) * 1997-04-09 1999-01-19 Lemna Corporation Method and device for treating wastewater

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9965829A1 *

Also Published As

Publication number Publication date
WO1999065829A1 (fr) 1999-12-23
KR20010052878A (ko) 2001-06-25
AU3892199A (en) 2000-01-05
JP2002518163A (ja) 2002-06-25
CA2335697A1 (fr) 1999-12-23

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