FR2473548A1 - METHOD FOR THE MAINTENANCE OF THE BIOLOGICAL ACTIVITY AND ADAPTATION OF BIOCENOSIS IN A WET AND BIOLOGICAL AIR PURIFICATION FACILITY REJECTED DURING OPERATING STOP PERIODS - Google Patents

Abstract

Acting by the supply of a nutrient solution, this process consists essentially in subjecting the exhaust air to a pre-wash and in supplying the biocenosis during periods of stoppage of operation, the pre-wash liquid retained, enriched by the materials contained in the air. In addition, the pre-wash liquid can be supplied to the biocenosis after separating the dispersed dust particles therefrom.

Description

The present invention relates to a process for

  biological activity and adaptation of the

  biocenosis in a wet and bio-purification plant

  rejected air logic, during periods of downtime

  tioning. The purification of air rejected by washing with water, for example in watering or spraying towers and the decomposition of pollutants by oxidation

  are generally known and have found

  many applications. Dissolved or colloidal organic compounds, and partly also mineral compounds are used as a source of food and are oxidized

  by micro-organisms (bacteria, fungi, proto-

  zoaires) that meet on watered bodies or on wastewater. For this purpose, see Patents of the German Federal Republic Nos. 26 56 689, 47 675, 20 207, US Pat. No. 22 00 581, French Patent No. 21 75 929 and US Pat. the patent

Dutch NO 71 02 133).

  It is known that a population of microorganisms (biocenosis) in a purification plant of this

  gender adapts to the food that is offered to him

  after a certain period of adaptation, even

  difficult to decompose can be destroyed with

success.

  During shutdown periods of the purification plant, for example during the

  at night or at the end of the week, the biocenosis must now be

  naked artificially alive by the supply of

  food and oxygen. It is appropriate that the numerical solution

  tritive also contains materials that must be

  destroyed during the periods of operation of the in-

  in order to avoid possible mismatches of the biocenosis, reducing the yield of the biological decomposition (see for this purpose the Patents of the German Federal Republic No. 26 56 689 page 15 and No. 20 207, page 4). But the preparation of these nutritive solutions is difficult, because on the one hand the composition of the rejected air is not well known with regard to its type.

  and its concentration, and that on the other hand it undergoes

  permanent fluctuations resulting from more variations or

  less important production. It would therefore be

  that the composition of the nutrient solution changes

  continually, which is impracticable in practice.

  It is therefore necessary to resolve the problem of

  the biological activity and the adaptation of a biocenosis during the shutdown periods of a rejected air purification plant, by the provision of a nutritive solution whose composition always corresponds to the current state of the composition of

gas discharged.

  The object of the invention is therefore to solve the problem

  by a method which will be described hereinafter.

  Prewashing with water precedes the operation of the

  biology of the rejected air. The materials that it contains

  the exhaust air, in the form of gases or vapors, dissolves

  wind up to saturation in the wash water on the floor of

  prewash. This result is reached more or less quickly

  depending on the contents of the exhaust air and their concentration. In the current case, however, it only takes a few hours. The prewash is done in a known manner, for example by passing the gases through a watering or spraying tower in which the prewash liquid is pumped, or by passing the gas so that it bubbles in the liquid Prewash. The prewash can be done in a separate part of the installation or in a part integrated in the absorber of the biological stage. It is useful to

  measure the amount of prewash liquid to de-

  end if the amount of material in the air that is released and dissolves in that liquid is sufficient to

  the uptake of bioconosis during periods of inactivity.

  But it is also possible to provide the biocenosis with the prewash liquid known nutrition materials, such as sugar, milk powder, phosphates, etc. In this case, the materials contained in the rejected air are no longer the sole source of nutrition but

  serve only to avoid possible mismatches. The quantity

  pre-wash liquid can be reduced in

the corresponding floor.

  If the exhaust air contains dust in addition to gaseous constituents and strong odor vapors, a

  Dusting carried out in the prewash stage is neces-

  sary. It is therefore possible to delete the floor of

  dusting which is frequently necessary in front of

  of the air purification plant. The floor of

  washing allows at the same time to saturate with water vapor

  the rejected air entering the purification plant.

  The removal of limestone and the addition of salt in the wash water can be removed in the floor

  biological purification. If the rejected air contains a quantity

  considerable amount of dust, preliminary purification,

  mechanical or possibly chemical (precipitation, flora

  culation) pre-wash water at the prewash stage

  may be necessary before use as a solution.

  nutrition. If the quantity of washing water present in the prewash stage is greater than that

  which is evacuated during downtime

  of the main washing stage, the excess of prewash liquid can of course be brought to the main washing stage, even during its operation, and

to flow through this one.

  Pollutant content of the rejected air

  with strong fluctuations are compensated

  in the prewash stage by the operations of

  sorption and absorption which compensates for

  instantaneous overload of the biological system. This allows

  puts a more regular load on the bio-level

  logic and greater efficiency.

Claims (3)

  1 - Method of maintaining the activity and   biological adaptation of the biocenosis in a plant   the wet and biological purification of air rejected during   during periods of downtime, by the furnace   forming a nutrient solution, characterized in that it consists essentially of prewashing   to the air rejected and to provide for the biocenosis during the   shutdown periods, prewash liquid   preserved, enriched by the substances contained in the air.   2 - Process according to claim 1, characterized   in that it also consists in providing the biocenosis   the prewash liquid after having separated the particles scattered dust. -   3 - Process according to claim 1 or 2, characterized   in that the prewash liquid is supplied to the   biocenosis in addition to known nutrients.