FR2776651A1 - Aerobic treatment of variable quantities of diverse winemaking effluents in conformity with increasingly demanding regulations - Google Patents

Abstract

A bioreactor includes a compartment with an immersed bed (21), a lithothamnic biological filter substrate for bacteria. The reactor (3) is fed continuously from a homogenization and buffering (storage) prechamber (2). The latter is fed with processing effluents, The prechamber and reactor (3) include a pipework grid (12, 18) diffusing air bubbles. The reactor outlet enters a settlement tank (4). Preferred features: The final settlement tank is connected to rejection (physical) filtration equipment. This tank also includes a recirculating lift pump (24) for sludge, which returns it to the prechamber, especially to ensure adequate oxygenation before again reaching the settlement chamber. The filtration equipment comprises a gravity filter containing gravel (26), with downstream connection to a lithothamnic filter, both filters being aerated. A low pressure volumetric pump (16) transfers between the prechamber and the bioreactor. Chamber (2, 3, 4) dimensions and circulation rates give the contents of the bioreactor a three-day residence time. The prechamber capacity is five days. The two compartments of the bioreactor are connected in series. Each has a lithothamnic bed and air diffuser grid. All chambers are integral to a horizontal, compartmented, elongated tank (1).

Description

TREATMENT PLANT FOR EFFLUENTS, ESPECIALLY VINICOLES

  The present invention relates more particularly to the treatment of discharges from the wine industry and more specifically wine effluents. These latter are liquid flows carrying polluting loads which vary enormously from one cellar to another and according to the different vinification operations such as harvesting, pressing, settling,

  fermentation, racking, filtration, devatting or fining.

  Wine effluents are characterized in terms of pollution by suspended matter, oxidizable matter, phosphorous matter and

nitrogenous materials.

  Official regulations are becoming more and more draconian as regards the contents, relating to the above pollutants, of discharges into the

  natural environment from these wine effluents.

  The known installations used for the purification of wine effluents are not really adapted to the wine activity, the particularities of which are the seasonal nature, the pollution reaching its peak during the harvest, devatting, racking and filtration periods, and

  large disparities in terms of volumes of effluents to be treated.

  Furthermore, the costs, yields and in particular the consistency in the results of such installations, taking into account in particular the highly variable character quantitatively and qualitatively of the effluents to be treated, are not

fully satisfactory.

  The present invention aims precisely to overcome these various drawbacks by proposing a treatment station for wine effluents, which is both efficient, taking into account the high lability of wine effluents and allowing

  continuous treatment absorbing pollution peaks.

  To this end, the invention relates to a treatment station for effluents, in particular wine-making, of the continuous type with aerated biological chamber, characterized in that said biological chamber comprises at least one compartment comprising a submerged bed, the bacterial support of which consists of lithothamne, in that said biological chamber is continuously supplied from a chamber with a homogenization and buffer function, itself supplied with effluents to be treated, the biological and buffer homogenization chambers being provided with an immersed network for the diffusion of fine air bubbles, the outlet of the biological chamber being connected

to settling means.

  According to another characteristic of the station according to the invention, said settling means consist of a final settling chamber, the outlet of which is connected to a filtration station before discharge, said chamber being provided with a sludge lifting pump to for recycling to the homogenization chamber, in particular for sufficient oxygenation

in the settling chamber.

  Advantageously, said filtration station is constituted by a refining chamber with gravity flow comprising a gravel filter connected downstream to a lithothamne filter, the two filters being provided with aeration means. According to yet another characteristic, the transfer between the buffer homogenization chamber and the biological chamber is connected using a

positive displacement pump.

  Other characteristics and advantages will emerge from the description which

  will follow of an embodiment of a station according to the invention, description

  given by way of example only and with reference to the appended drawings in which - Figure 1 is a view in axial vertical section of a reactor implementing the wine effluent treatment system according to the invention, and - Figure 2 is a schematic sectional view of a filter system

  gravel and lithothamne associated with the reactor of Figure 1.

  In FIG. 1, there is shown in 1 a reactor consisting of a cylindrical tank, of horizontal axis, divided into three interior compartments respectively 2, 3 and 4 by vertical partitions respectively 5 and 6,

  each compartment being provided with at least one access manhole 7.

  One of the end compartments 2 defines a so-called homogenization chamber provided with an inlet 8 for wine effluents to be treated, in the upper part of the compartment, the effluents falling on a deflector 9

jet breaker.

  The central compartment 3 defines a biological chamber and the other end compartment 4 defines a decantation chamber provided with an outlet 10 to a final filtering system (not shown) before discharge into the

natural environment.

  Room 2 is the largest in volume and very slightly

  greater than half of the reactor in the embodiment shown.

  The average level of effluents stored in the

  bedroom 2, it being understood that this level can vary within wide limits.

  In the lower part of the chamber 2 is immersed a network of diffusers 12 of fine air bubbles connected by a pipe 13 to an external blower

14 fitted with an air filter 15.

  The partition 5 occupies the entire internal section of the reactor 1 and the transfers between the chambers 2 and 3 are carried out using a pump

  volumetric self-priming 1 6, external or internal.

  The pump 16 discharges the effluents from the chamber 2 downwards from the biological chamber 3, through a pipe 17, below a second network of diffusers 18 with fine air bubbles also supplied by the blower 14,

by pipeline 19.

  The network of diffusers 18 is arranged under a submerged bacterial bed consisting of a horizontal perforated grid 20 of stainless steel on which is placed a bed of lithothamne 21. At 22 is symbolized the average level of the

liquid in room 3.

  Chamber 3 communicates with decantation chamber 4 through a

overflow tube system 23.

  Chamber 4 with an inclined bottom towards the center is equipped with a pump 24 for lifting the sludge, recycled by a pipe 25 upstream

from bedroom 2.

  In 26 is shown a device for adjusting the pH of the liquid in the

bedroom 2.

  The outlet 10 of the reactor is preferably connected to a gravity flow filtration system of the type illustrated in FIG. 2 and comprising a first gravel filter 27 contained in a tank 28 provided with a ventilation means followed by a second filter 29 with lithothamne contained in a second tank 30 also provided with ventilation means. The output 31 of the second filter 29 rejects

  purified water in the natural environment.

  The tanks 28, 30 are provided with a cover for surface maintenance

filters.

  The operation of the station described above is as follows.

  The wine effluents to be treated are sent directly to chamber 2 after passing through a preliminary filtration device (not shown) intended to retain the solid materials and the non-digestible elements. The volume of the chamber 2 is calculated as a function of the flow rate of the biological chamber 3 and so as to respond to an amount of effluent equivalent for example to five days of effluent during the peak discharge period of

winery.

  This, together with the forced and efficient ventilation provided by the network of diffusers 12, ensures good homogenization thanks to the time.

of sufficient effluent.

  The network of diffusers 12 naturally remains permanently submerged. The transfer of effluents from chamber 2 to chamber 3 takes place by pump 16 which allows, by appropriate control, to ensure optimal homogenization in chamber 2, in particular due to good dilution of the impact pollution peaks in a buffer volume, and a

  regular feeding of the organic bed 21.

  The lithothamne constituting the bed 21 is a well-known product consisting of a seaweed meal called Maërl used for a long time to

soil improvement.

  By way of example, the lithothamne bed 21 can have a surface of 3 m 2, a thickness of around thirty centimeters and a weight of 500 kg, for

  a biological chamber 3 with a volume of the order of 3500 liters.

  The lithothamne bed is particularly effective. An excellent development of the biomass has been observed on the lithothamne, eight days after sowing from sewage treatment plant sludge

wineries.

  Biomass development has taken place

particularly uniform.

  The wine effluent treatments in accordance with the invention, respecting a stay rate of three days in the biological chamber, have

  achieved a room cleaning rate of around 93%.

  The recirculation of the sludge sent by the pump 24 in the chamber 2 has in particular the advantage of maintaining in the settling chamber a

  sufficient dissolved oxygen level to avoid the anaerobic environment.

  Recirculating sludge also avoids the problem of emptying

too frequent.

  The pump 24 is for example controlled by a timer in order to control the recirculation flow which is of the order of 30% of the input flow

  effluents (8) in chamber 2.

  The prediction of the refining system in Figure 2 by gravel filter and lithothamne allows better control of the efficiency of the treatment station and guarantees the reproducibility of this efficiency despite the very labile nature

effluents.

  It should be noted that, as a variant, the buffer homogenization chamber 2

  could be physically separated from the biological chamber 3.

  Furthermore, the station is simple in its design, implementation and operation, it is relatively economical and easily adapted

  at various sizes of wineries.

  Finally, the invention is obviously not limited to the embodiment shown and described above, but on the contrary covers all of its i15 variants, in particular as regards the methods of making the bed.

submerged in lithothamne 21.

  Thus the biological chamber 3 could comprise two compartments arranged in series and each provided with a bed of lithothamne and

a network of broadcasters.

  The treatment station according to the invention can also be used

  for non-wine effluents, for example domestic effluents.

Claims (7)

  1. effluent treatment station, in particular wine-making, of the continuous type with aerated biological chamber (3), characterized in that said biological chamber comprises at least one compartment comprising a submerged bed (21), the bacterial support of which consists of lithothamne, in that said biological chamber (3) is continuously supplied from a chamber (2) with a homogenization and buffer function, itself supplied with effluents to be treated, the biological chambers (3) and for homogenization -buffer (2) being provided with an immersed network (12, 18) for diffusing fine air bubbles, the outlet of the biological chamber (3) being connected to means of decantation (4).   2. Station according to claim 1, characterized in that said decantation means are constituted by a final decantation chamber (4) whose outlet is connected to a filtration station before discharge, said chamber (4) being provided with a sludge lifting pump (24) for recycling purposes to the homogenization chamber (2) in particular for purposes   sufficient oxygenation in the settling chamber (4).   3. Station according to claim 1 or 2, characterized in that said filtration station is constituted by a refining chamber with gravity flow comprising a gravel filter (26) connected downstream to a filter   lithothamne (28), the two filters being provided with ventilation means.   4. Station according to one of claims 1 to 3, characterized in that   transfer between the buffer homogenization chamber (2) and the chamber   biological (3) is carried out using a positive displacement pump (16).   5. Station according to one of claims 1 to 4, characterized in that   the dimensions of the chambers (2, 3, 4) and the circulation flow of the media between the chambers are determined so as to have a residence time of the medium in the biological chamber (3) of three days and a capacity for the chamber homogenization-storage buffer with a volume equivalent to   five days of effluents during peak discharge periods.   6. Station according to one of claims 1 to 5, characterized in that the biological chamber (3) comprises two compartments arranged in series and   each provided with a lithothamne bed and a network of diffusers. 7. Station according to one of claims 1 to 6, characterized in that   the buffer homogenization (2), biological (3) and decantation chambers   (4) are combined in a reactor (1) formed by an elongated, horizontal, compartmentalized tank.