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
  • C02F3/30—Aerobic and anaerobic processes
  • C02F3/301—Aerobic and anaerobic treatment in the same reactor
• • 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
  • C02F3/006—Regulation methods for biological treatment
• • 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
  • C02F3/30—Aerobic and anaerobic processes
  • C02F3/302—Nitrification and denitrification treatment
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2209/00—Controlling or monitoring parameters in water treatment
  • C02F2209/04—Oxidation reduction potential [ORP]
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2209/00—Controlling or monitoring parameters in water treatment
  • C02F2209/05—Conductivity or salinity
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2209/00—Controlling or monitoring parameters in water treatment
  • C02F2209/15—N03-N
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2209/00—Controlling or monitoring parameters in water treatment
  • C02F2209/16—Total nitrogen (tkN-N)
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2209/00—Controlling or monitoring parameters in water treatment
  • C02F2209/22—O2
  • C02F2209/225—O2 in the gas phase
• • 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

Definitions

• the invention relates to the field of effluent treatment and, mainly, the field of treatment of waste water, industrial or domestic.
• the present invention relates to a method for treating the nitrogen pollution contained in such effluents intended to be used in a biological filter (also called “biofilter”).
• a biological filter also called “biofilter”
• Biological filters are used in the treatment of wastewater in order to eliminate, or at least to strongly reduce, among other things the carbon pollution and nitrogen pollution contained in them. They use a biomass support consisting of particles which may be denser or less dense than water, which also makes it possible to physically filter the effluent.
• autotrotrophic transforms ammonia pollution into nitrates.
• This operation called nitrification, requires the presence of oxygen in the water to be treated. This operation therefore takes place in an aerobic zone of the biological filter;
• heterotrophic transforms nitrates into nitrogen gas.
• This operation called denitrification, requires the presence of carbon pollution used as a substrate by heterotrophic biomass, and the absence of molecular oxygen.
• the oxygen brought by the nitrates into the anoxic zone of the reactor is used by the bacteria to eliminate carbon pollution.
• nitrification and denitrification can be carried out in two main modes.
• the first consists of a pre-denitrification using the carbon pollution present in the effluent to be treated, followed by nitrification.
• the second consists of a pre-nitrification followed by a denitrification then requiring an external carbon source.
• a recirculation of part of the treated water is returned to the anoxic zone in order to feed the heterotrophic bacteria therein as a substrate.
• denitrification and nitrification necessarily require two filters connected in series, one operating in aerobic mode and the other operating in anoxic mode.
• the objective of the present invention is to provide a method for treating the nitrogen pollution of an aqueous effluent which does not involve such drawbacks.
• an objective of the invention is to propose such a method allowing an economic gain during the construction of the installations for its implementation, compared with the installations of the state of the art.
• Another objective of the present invention is to describe such a method which makes it possible to save energy during its implementation.
• Yet another objective of the invention is to propose such a process which makes it possible to achieve better quality of the treated effluent.
• the invention which relates to a biological treatment process by nitrification / denitrification of an effluent comprising a step consisting in passing said effluent through a biological reactor with cultures fixed on at least one bed of granular material and provided means of contribution of oxygen, characterized in that it consists in continuously aerating essentially the whole of said bed of granular material, in measuring at least one parameter representative of the oxygen consumption of said fixed cultures and in that it comprises a step consisting regulating the operation of said oxygen supply means as a function of the results of said step of measuring said parameter and of a set value thereof, said method authorizing essentially simultaneous nitrification / denitrification of said effluent.
• the method according to the invention therefore makes it possible to carry out, in a single biological filter (biofilter), a complete treatment of the nitrogen pollution of an effluent by nitrification / denitrification, but without physically delimiting within the bed of granular material constituting the biofilter an area operating in anoxia and an area operating in aerobic.
• Such a process makes it possible to obtain a better oxygen supply efficiency compared to techniques using a biofilter provided with an intermediate oxygen supply ramp and thus to significantly reduce the operating costs.
• the method according to the invention also makes it possible to obtain a better quality rejection than in the methods of the state of the art.
• the set value used in the case of the present process may vary depending on the nature of the effluent treated. According to an advantageous preferential variant of the process, this set value will be determined as a function of the nitrogenous charge of the effluent or by a level of pollution measured at the outlet of said biofilter.
• the process comprises an additional step consisting in recirculating in the biological reactor at least a part of the treated effluent. It will be noted that the method according to the invention makes it possible to reduce the recirculation rates.
• the parameter representative of the oxygen consumption of the cultures fixed on the biofilter measured in the context of the present process may be constituted in particular by the concentration of dissolved oxygen in the effluent, by the oxy-do-reduction potential of the latter or also by its ammonium concentration, its nitrates concentration or its NADH concentration (nicotinamide adenosine dinucleotide hydrogenase).
• the measurement of this parameter can be carried out on the treated effluent leaving the biological reactor but also on the effluent passing through it.
• the parameter representative of the oxygen consumption by the fixed cultures is constituted by the concentration of dissolved oxygen in the treated effluent (measured either at the outlet of the reactor or inside it for example in the water layer preceding the outlet of the reactor effluent) and the method is implemented so as to maintain a dissolved oxygen concentration of this treated effluent of between 3 and 8 mg per liter and preferably between 4 and 7 mg per liter.
• This value can be defined and fixed by a continuous measurement on the treated water (for example NH 4 ) or as a function of the water temperature
• the method will include an additional step consisting in adding to said effluent at least one carbon source. Such a case will occur when it is desired to obtain an effluent having a low overall nitrogen content and when there is not enough biodegradable organic carbon in the effluent to be treated.
• the method according to the invention may also include an additional post-denitrification step.
• the present invention also relates to any installation specially designed for the implementation of the process described above comprising at least one biological reactor with fixed cultures provided with oxygen supply means characterized in that it comprises means for measuring the '' at least one parameter representative of the oxygen consumption by said fixed cultures, said measuring means being provided at the outlet of said reactor and / or inside of the latter, and means for regulating said oxygen supply means as a function of said measurement.
• the method can be implemented on any type of biological reactor with fixed cultures.
• the installation has a biological reactor of the ascending type and comprises a monolayer or multilayer fluidized bed of at least one granular material as well as means for recirculating the treated effluent.
• the measuring means in question include at least one sensor of the dissolved oxygen concentration installed in the slice of water present above said bed of granular material at a distance preferably between 5 cm and 40 cm above from the top surface of it.
• the installation may also include at least one structure for separating the treated effluents and the granular material and measuring means which will advantageously in this case be installed at the outlet of said structure.
• - Figure 1 shows an installation for implementing the method
• - Figure 2 shows the evolution of the concentration of ammonia nitrogen and nitrates of an effluent after treatment by the process according to the invention and of an effluent after treatment according to the conventional process;
• FIG. 3 shows the air velocities and the dissolved oxygen concentrations at the outlet of the biofilter in the case of the process according to the invention and in the case of a conventional process.
• FIG. 1 constituted by an ascending biofilter 1, including a filter bed 2 made up of at least one granular material lighter than water (polystyrene beads) an aeration ramp 3 of the filter bed 2 provided at the base of the biofilter, means for supplying 4 with water to be treated provided in the lower part of the filter, means for discharging 5 of the treated water provided in the part upper part of the biofilter, means for recirculating 6 part of the treated water, means 7 for measuring the dissolved oxygen concentration of the effluent and of the means 8 for regulating the operation of the aeration means 3 as a function of the results of the measurements carried out by said measuring means 7.
• a filter bed 2 made up of at least one granular material lighter than water (polystyrene beads)
• aeration ramp 3 of the filter bed 2 provided at the base of the biofilter
• means for supplying 4 with water to be treated provided in the lower part of the filter
• the filter beds of the two installations have a height of filter material of 2.75 m.
• the filtration speed was set at 3.0 m / h and recirculation at a rate of 100% of the feed rate.
• Table 1 presents the results obtained using the method according to the invention, obtained over a day of treatment (daily average), in the case of the method according to the invention and in the case of the conventional method.
• the process according to the invention has the advantages: - of not requiring the installation of an intermediate ramp within the material to delimit within a single reactor two distinct zones, namely an aerated zone and an unventilated zone;

Landscapes

• Life Sciences & Earth Sciences (AREA)
• Organic Chemistry (AREA)
• Microbiology (AREA)
• Hydrology & Water Resources (AREA)
• Engineering & Computer Science (AREA)
• Environmental & Geological Engineering (AREA)
• Water Supply & Treatment (AREA)
• Chemical & Material Sciences (AREA)
• Biodiversity & Conservation Biology (AREA)
• Molecular Biology (AREA)
• Health & Medical Sciences (AREA)
• Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
• Separation Using Semi-Permeable Membranes (AREA)
• Biological Treatment Of Waste Water (AREA)
• Apparatus Associated With Microorganisms And Enzymes (AREA)
• Immobilizing And Processing Of Enzymes And Microorganisms (AREA)
• Micro-Organisms Or Cultivation Processes Thereof (AREA)
• Treating Waste Gases (AREA)

Priority Applications (8)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (12)

Cited By (2)

Families Citing this family (8)

Citations (6)

Family Cites Families (2)

• 1998
  • 1998-12-23 FR FR9816508A patent/FR2787782B1/fr not_active Expired - Fee Related
• 1999
  • 1999-12-23 WO PCT/FR1999/003280 patent/WO2000039034A1/fr not_active Ceased
  • 1999-12-23 ES ES99961167T patent/ES2253923T3/es not_active Expired - Lifetime
  • 1999-12-23 HK HK02102347.4A patent/HK1040696B/zh not_active IP Right Cessation
  • 1999-12-23 US US09/856,831 patent/US6632365B1/en not_active Expired - Lifetime
  • 1999-12-23 JP JP2000590953A patent/JP4474500B2/ja not_active Expired - Fee Related
  • 1999-12-23 AU AU17866/00A patent/AU1786600A/en not_active Abandoned
  • 1999-12-23 AT AT99961167T patent/ATE309966T1/de active
  • 1999-12-23 DE DE1999628443 patent/DE69928443T2/de not_active Expired - Lifetime
  • 1999-12-23 DK DK99961167T patent/DK1144318T3/da active
  • 1999-12-23 CA CA 2358415 patent/CA2358415C/en not_active Expired - Fee Related
  • 1999-12-23 EP EP99961167A patent/EP1144318B1/fr not_active Expired - Lifetime

Patent Citations (6)

Non-Patent Citations (1)

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