DD278574A1 - PROCESS FOR MICROBIAL REMOVAL OF ORGANIC COMPOUNDS - Google Patents

Abstract

The invention relates to a method for the microbial degradation of organic compounds in liquids of high alkali or Erdalkalichloridbelastung. The invention can be used in plants for biological wastewater treatment, in which highly saline liquids must be treated, in which strong as they come from the coal processing, the fur processing or Lederindustie. The new bacterial strain IMET 11333 tolerates NaCl concentrations of up to 150 g / l and thus enables the treatment of wastewater phases which until now could only be microbially cleaned after extensive pretreatment.

Description

Field of application of the invention

The invention relates to a microbiological wastewater treatment process. It can be used in conventional aerobic fermentation plants where degradation of organic compounds in highly saline liquids is required.

Characteristic of the known technical solutions

In the known method for degradation of organic compounds, it is a significant problem when the liquid phases to be cleaned have a high load of alkali or alkaline earth chlorides, as z. B. with effluents of the salt coal refinement, the leather industry or fur processing is the case. Reductions in the degradation efficiency of the microorganisms up to 40% are reported in the literature at NaCl contents of 2 to 5% by weight (G.W. Lawton, C.V. Eggert:

Seawagd and industrial wastes 29 [195711228ff .; H. Ziemann: Acta hydrochim. hydrobiolog. 1 [1973] 257).

According to SU 1175963, the growth of Acinetobacter calcoaceticus is completely inhibited when the NaCl content of the effluent to be treated exceeds 6.5% by weight.

To overcome these disadvantages, additional Veifahrensstufen be installed to eliminate inorganic salts such as precipitation or ion exchanger in complex wastewater treatment plants, making the process technologically and economically complex.

Object of the invention

The invention has the goal of realizing the degradation of organic constituents, in particular lower fatty acids, carbohydrates and proteins, in liquids of high alkali or alkaline earth metal chloride loading in a technologically simple manner and without additional treatment stages for salt reduction.

Essence of the invention

The object of the invention is to select and use a bacterial strain which has a high halotolerance with respect to NaCl and which utilize different carbon sources at a sufficient rate of growth

According to the invention, the object is achieved by using the new halotolerant bacterial strain IMET 11333 in an aerobic cultivation method, in which the wastewater to be purified serves as a carrier of the C source.

The microbial degradation process is carried out in the temperature range from 20 to 45 ° C, preferably from 30 to 30 ° C and in the pH range of 5 to 8, preferably 6.6 to 7.4.

The salt load can be up to 150g NaCl / l to be treated liquid without noticeable adverse effects on the biomass growth and the degradation compared to lower fatty acids such as acetic acid, PrprprioniHire or butyric acid, carbohydrates such as glucose, lactose or galactose and proteins are observed.

In addition to oil, the new bacterial strain tolerates other alkali or alkaline earth chlorides, carbonates or sulfates.

Ammonium salts of these anions are to be regarded as alkali salts.

The use of the bacterial strain is carried out in a manner that is customary for biological wastewater treatment. The growth of the inoculation material is expediently started with pure C sources and stepwise carried out an adaptation of the biomass to DC's of medium to be treated. The actual cultivation process for decomposing the organic compounds can be carried out either batchwise or continuously; in the case of continuous process control, a flow rate of a maximum of 0.14 / h must be maintained.

Th ^e new Bakterienstarnm was iiimciiegt in the IMET-Culture Collection of the Central Institute of Microbiology and experimontelle therapy Jena the Academy of Sciences of OCm and registered under number IMET 11,333th

It is characterized as follows:

cell morphology

after cultivation in liquid culture with acetate:

Shape: chopsticks

Size: 1.24pm wide; 6.2m long

The tribe is gram-negative

colony morphology

On standard agar containing 15% NaCl, 2% acetate and 0.2% yeast extract, the following colonies are formed at pH 6.9:

- circular, hemispherical, entire, shiny, with a diameter of 1 to 1,5μηι.

- Bark-like texture, fine-grained structure, white color

Other features

The optimum temperature is 38 ⁰ C, the growth begins on solid nutrient media after 8 days and is optimal after 12 days. The temperature range for growth is between 20 and 45 ° C. The pH range is between 5.8 and 7.8 with the pH optimum at 6.9.

The bacteria show good assimilation ability for the following substances:

Glucose, calactose, glycerol, lactose, citrate, acetic acid, propionic acid, butyric acid and protein compounds.

The bacterial biomass has a crude protein content of 58 to 68% duf.

By following examples, the invention will be explained in more detail.

embodiments

example 1

In a stirred fermentor 5I bred inoculum of the bacteria IMET 11333 are used at a concentration of 1.5 g / l. The temperature is adjusted to 34 ° C, the pH to 6.8. The medium, which is balanced for 10 g BTS / I, is gassed with 86 l / lh of air. There is a discontinuous cultivation until the desired biomass concentration of 10 g / l. During the growth process, the pH is controlled with a 2% sulfuric acid. The nutrient medium had (for 1 g of biomass) the following composition per liter:

KH ₂ PO ₄ 35 mg

H ₃ PO ₄ <85%) 0.027 ml

MgSO ₄ x 5 H ₂ O 25 mg

CuSO ₄ × 5 H ₂ O 0.78 mg

FeCl ₂ x 4 H ₂ O 1.20 mg

ZnCl ₂ 0.32 mg

MnSO ₄ x 4 H ₂ O 1.83 mg

CoSO ₄ x 7 H ₂ O 0.04 mg

CrCl ₃ × 6 H ₂ O 0.08 mg

NiSO ₄ x 7 H ₂ O 0.11 mg

Na ₂ MoO ₄ χ 2 H ₂ O 0.04 mg

Al ₂ (SO ₄ I ₃ X 18H ₂ O 0.19 mg

H ₂ BO ₃ 1.29 mg

Ca (NO ₃ I ₂ χ 4 H ₂ O 0.88 mg

CH ₃ COOH (80%) 6.12 ml

The NaCl content of the fermentation medium was 120 g / l.

Nutrient solution and sulfuric acid are successively added to the fermentation medium so that the following concentrations are maintained in the culture fluid:

P (as phosphate): 20 to 150mg / l

N (as ammonium ions): 20 to 150 mg / l.

The subsequent continuous cultivation was carried out at a flow rate of 0.12 / h. The pH was controlled with 10% NH ₄ OH solution. The above limits for P and N were met. Under these conditions, a productivity of 1.0 g / lh was achieved. The degradation of the acetic acid in the medium is carried out from 25 g / l initial concentration to 0.5 g / l.

Example 2

The cultivation was carried out as described in Example 1, except that the acetic acid was replaced by butyric acid. At a flow rate of 0.1 / h, a productivity of 0.95 g / L was achieved. The decomposition of the butyric acid was carried out from 20 g / l initial concentration to 0.8 g / l. The NaCl content was 50 g / l of fermentation mixture.

Example 3

The cultivation was carried out as described in Example 1, the acetic acid was replaced by glucose and the fermentation medium had a NaCl content of 100 g / run. The flow rate was 0.12 / h. Under these conditions, a productivity of 0.9 g / lh was achieved. The degradation of glucose from 19g / l initial concentration down to 1 g / l.

Example 4

The cultivation was carried out to reduce the fatty acid content of a coal waste water containing 4 g / l monophenols, 18 g / l fatty acids, 1 g / l CO ₂ , 0.1 g / l H ₂ S and 20 g / l NaCl. The wastewater was mixed in the ratio 1: 2 with the medium mentioned in Example 1 and subjected to a batch fermentation at a fermentation time of 20 h. The fatty acid content was lowered from 18 g / l to 1 g / l.

Examples

A wastewater from the fur processing industry, the washed Fiweiß and 15g / l NaCl contained and had a CSV value of 800 mg / l was mixed with fermentation medium according to Example in the ratio 2: 1 and subjected to a batch fermentation for 15h. The CSV value could be lowered to 100mg / l.

Claims (4)

1. A method for microwave degradation of organic compounds, in particular of lower fatty acids, carbohydrates and proteins, in liquids high alkali or Erdalkalichloridbelastung, by an aerobic cultivation process with bacteria, characterized by using the new halotolerant strain IMET 11333th 2. The method of claim 1, characterized by a Halotoleranzobergrenze the new strain of 150g NaCl / l liquid phase. 3. The method according to claim 1, characterized by the cultivation parameters: temperature range 20 to 45 ° C, preferably 30 to 38 ° C and pH range 5 to 8, preferably 6.6 to 7.4. 4. The method according to claim 1, characterized by a flow rate of D _max = 0.14 / h in continuous process control.