FR2617830A1 - PROCESS FOR THE BIOLOGICAL PURIFICATION OF METHANOL IN WASTEWATER - Google Patents

Abstract

According to the invention, the waste water containing methanol is subjected to neutralization with orthophosphoric acid, they are enriched with nitrogen sources, after which the strain Methylomonas metanica B-2576, deposited at the Central Museum of Micro -industrial organizations Vsesojuznogo nauchno-issledovatelskogo instituta genetiki i selektsii promyshlennykh mikroorganizmov. The strain cited is cultivated on the medium indicated until the purification of the waste water from methanol. The process for the biological purification of methanol from waste water will find application in companies extracting and processing natural gas containing hydrogen sulphide.

Description

The claimed invention concerns the biological purification of

  wastewater treatment, and more specifically a biological purification process aimed at ridding

residuals of methanol.

  The invention will find application in the

  extraction and treatment of natural gas

holding hydrogen sulfide.

  At present, we know the culture of micro-

  organisms belonging to the various physiological groups, 0 obtainable on nutrient media containing methanol

as a source of carbon.

  Thus, for example, a method of culturing yeasts of different species on a medium containing methanol (V. S. Podgorsky "Fiziologia i metabolizm metanolusvaivajuschikh drozhzhei", Eds. "Naukova dumka", Kyiv, 1982) is known. Yeast culture, assimilating methanol, is also known on nutrient media in the

  composition of which between the residual liquid of

  ture ("braga") resulting from the hydrolysis production of

  Yeasts ("Acta microbiol., Bulg.", 1970, v. 7, pages 49-54).

  Named processes for culturing microorganisms

  assimilating methanol can be used for the purification of

  industrial waste water containing methanol. Thus, for example, the yeast culture of the species Hansenula polymorpha is carried out on waste water containing methanol, resulting from the extraction

  and the treatment of natural gas containing hydrogen sulphide

  which gives the possibility of purifying methanol from

  waste water cited (SU, A, 963960).

  0 In accordance with this process, the purification of waste water

  duanes containing methanol is carried out using

  yeasts at a temperature of 36-38 C in a neutral medium

  which is available from orthophosphoric acid up to pH 3.9-4.0 and enriched with microelements, nitrogen sources and vitamins. The purification of waste water by this known method makes it possible to obtain water containing no

only traces of methanol.

  A disadvantage of the named process is a consumer

  considerable amount of orthophosphoric acid, micro-elements and vitamins necessary to obtain

  nutritious environment conducive to the development of cul-

  species Hansenula polymorpha.using methanol.

  Thus, a volume of 2000 m of wastewater requires, for neutralization, 3 m3 of concentrated orthophosphoric acid more than 250 kg of micronutrients, 3.6 kg of thiamine and g of destibiotin. The disadvantage of the known process is also due to a slow dilution rate of 0.5 l / h: 0.1 hh-2, which requires considerable volumes of the purification plants, since the residence time of waters to

  to purify in the purification works is 10 hours.

  It has therefore been proposed to put a biological purification process for wastewater at the point, aimed at

  to release methanol, in which a micro-

  organism through which the purification process would be carried out under advantageous conditions from the point of view

  through the intensification of the process.

  The solution is that in the process of

  biological supply of methanol from wastewater by

  culture of a micro-organism on pre-treated wastewater

  latency neutralized by orthophosphoric acid and

  enriched sources of nitrogen, until the purification of metha-

  in accordance with the invention, in

  quality of the micro-organism, the strain Methylomo-

  nas metanica B2576, deposited at the Central Museum of Micro-

  industrial organizations Vsesojuznogo nauchno-issledovatel-

  skogo instituta genetiki i selektsii promyshlennykh mikrooi

Ganizmov (04.07.1982).

  Thanks to the present invention, the consumption of

  reagents necessary for the purification of 1 m3 of

  duaires is reduced by 12 times in comparison with the

  water purification process known, with a double intensification

cation of the process.

  It is rational, in accordance with the invention, to previously neutralize the residual waters with orthophosphoric acid to a pH of 5.5-7.0, and to carry out the cultivation of the microorganism cited at a temperature of

-37 C.

  Other features and advantages of the invention

  will be better understood by reading the description of the

  wastewater treatment process that will follow and

  several examples of the realization.

  To carry out the claimed process, the culture assimilating methanol is isolated. For this, the soil polluted with methanol is placed in a vortical glass column and the wastewater containing methanol resulting from the gas exploitation fields, previously diluted with a nutrient medium, is passed through the soil. at a methanol concentration of 1 g / l. A mineral nutrient medium containing, in g / dm3: K2HPO4 1.0 is used; MgSO4.7H2O: 0.5; NaCl: 0.02

  FeSO4.7H2O: 0.03 NH4NO3: 0.5; pH = 7.0. We gradually increase

  the methanol concentration of the medium to 10.0 g / dm3, decreasing the dilution of the actual waste water with the nutrient medium. The methanol content of the waste water is increased until its complete use of the residual water of the preceding dilution is obtained. At the feed stage of the waste water containing 10.0 g / dm

  methanol, and in the absence of the latter in residential water

  dune out of the column, is carried out the isolation o the pure culture of the bacterium by seeding the contents of the column on a mineral nutrient medium agarized the

  above-mentioned composition containing 2.0 g / dm3 of methanol.

  Under stationary conditions, the crop consumes methanol in lower concentrations than during its

  Continuous flow culture. The growth of the micro-

  organism on medium containing 2.0 g / dm3 of methanol testifies to its use by culture, as the

  Methanol is a unique carbon source.

  The strain Methylomonas metanica B-2576 is characterized

  morphological and physiological-biochemical characteristics

  following: the cells are straight rod-shaped, mobile, have a polar flagellum, gram-negative, aerobic, multiply by division, the dimensions of the cell are 0.6xl mm; colored collonnies

  pink or cream are mucous, the dimensions of the colo-

nies being 3-4 mm.

  The indicated strain does not develop on ordinary nutrient media of the meat-peptone agar type,

  it only grows on media containing methanol.

  The isolated technical culture Methylomonas metanica B-2576 is deposited in the Central Museum promyshlennykh mikroorganizmov Vsesojuznogo nauchnoissledovatelskogo

  institute genetiki i selektsii promyshlennykh microorganiz-

mov (04.07.1982).

  The claimed method for the biological purification of methanol from waste water is to neutralize methanol-containing wastewater with acid

  orthophosphoric acid to a pH of 5.5-7.0 and to

  chir with nitrogen sources, introducing, for example

ammonium nitrate.

  The wastewater Methylomonas metanica B-2576 is then introduced into the waste water and the

  culture of the microorganism cited while maintaining the temperature

  at 20-37 ° C. As studies show, the culture of the microorganism indicated at a temperature of 20-37 ° C ensures the use of methanol by the bacteria up to the trace quantities or the complete absence of the methanol. : in waste water. At a temperature below

   C, the process of using methanol by the micro-

  body is significantly slowed down, and for 48

  hours of culture only 450 mg of methanol are consumed

  caused by bacteria in 1 1 of wastewater. At temperatures

  below 37 C, the strain Methylomonas metanica

  B-2576 does not grow and does not use methenol.

  The residual waters are pre-neutralized with orthophosphoric acid to a pH of not less than 5.5, since at a lower pH the growth and use of methanol by Methylomonas metanica strain B-2576 is slowed. A low alkali content of waste water (pH above 7.0) is also unfavorable to a complete consumption of

  methanol by the cited microorganism.

  The claimed process for the biological purification of waste water makes it possible to purify waste water with a high concentration of methanol (5% by weight). The

  methanol is then fully used by microorganisms.

  and it is not found in purified water or

trace quantities.

  Through the use of the strain Methylomonas metanica B-2576 in place of the yeast culture of

  type Hansenula polymorpha previously used for

  wastewater treatment, the purification process becomes economically more advantageous since, firstly,

  the consumption of orthophosphoric acid for

  waste water decreases considerably, not up to a pH value of 3.9-4.0, but up to pH 5.5-7.0, secondly, strain Methylomonas metanica B-2576 n absolutely does not require vitamins such as thiamine and destiobiotin for its development

and the use of methanol.

  The reduction of the residence time of the wastewater in the purification apparatus, in comparison with that used previously, makes it possible to intensify twice the

purification process.

  During the purification of the waste water by the claimed process a bacterial biomass, containing more than 70% of raw protein, is accumulated, which is then used to

  prepare various protein products.

Example I

  In a fermenter for a continuous culture of micro-

  organisms with a capacity of 5 1, waste water containing 50.0 g / dm3 of methanol, resulting from the extraction and treatment of natural gas containing

  Hydrogen sulfide. Then, in the fermen-

  0.4 ml / dm 3 orthophosphoric acid and 150 mg / dm 3 ammonium nitrate. The waste water is pre-diluted with a synthetic nutrient medium to a methanol concentration of 10 ml. g / dm3, and seeded with strain Methylomonas metanica B-2576, cultured in Erlenmeyer flasks under shaking on medium.

  synthetic nutrient containing methanol at one

  5.0 g / dm The methanol concentration of the wastewater is gradually increased to 50.0 g / dm3, decreasing

  dilution with the synthetic medium. We keep the con-

  concentration in orthophosphoric acid in residential waters

  duaries at the level of 0.4 ml / dm3 (pH = 6.5). Temperature

  wastewater is 30 ° C. After obtaining the

  concentration in the strain Methylomonas metanica B-2576 of + g / dm3, the culture of the bacteria is carried out in a flow of the wastewater at a dilution coefficient of 0.2h, which corresponds to a residence time of the wastewater at purify in the fermenter

equal to 5 hours.

  During 10 days of continuous cultivation of Methylomonas metanica strain B2576 on waste water containing methanol, the biomass of microorganisms is stably maintained at the level of 37 + 2 g / dm3, which indicates a high degree of use of methanol by microorganisms. Purified wastewater does not contiel

  then methanol only in trace concentrations.

Example 2

  The water purification process is carried out

  Methanes containing methanol in a manner quite similar to that described in Example 1. However, the residual water is first neutralized with orthophosphoric acid to a pH of 5.5. We keep

  the temperature of the waste water at the level of 20 C.

  The cultivation of the strain Methy-

  lomonas metanica B-2576 in a periodic diet at a

  O optimal starting concentration of methanol of 1 g / dm3.

  The purification process is undertaken during 48

hours with vigorous agitation.

  Purified wastewater, 48 hours after cultivation,

contains 0.002 g / dm3 of methanol.

Example 3

  The process of purification of residual water is carried out

  as in Example 1. However, a neutralization is carried out

  pre-treatment of wastewater with orthoacidic acid

  phosphoric up to pH = 7.0. We keep the temperature

  O wastewater at the level of 370C.

  The cultivation of the strain Methylomonas metanica B-2576 is initiated periodically at a concentration

starting point in methanol of I g / dm3.

  The purification process is started for 48 hours with vigorous stirring. The purified waste water, after 48 hours of culture of the microorganisms mentioned, does not

does not contain methanol.

Claims (3)

  1. Process for the biological purification of methanol in waste water by culturing a microorganism on said waste water, previously neutralized with orthophosphoric acid and enriched in nitrogen sources until they are purified from methanol, characterized   in that as a micro-organism, we use the   Methylomonas metanica B-2576, deposited at the Central Museum   industrial microorganisms Vsesojuznogo nauchno-   issledovatelskogo instituta genetiki i selektsii promysh- lennykh mikroorganizmov.   2. Method according to revendicaton 1, characterized in that prior neutralization of wastewater to   orthophosphoric acid to pH 5.5-7.0.   3. Method according to any one of the claims   i or 2 characterized in that cultivation of the strain Methylomonas metanica B-2576 is carried out at a temperature from 20-37 C.