RU2270807C2 - Biochemical method for freeing waste waters of phenol compounds - Google Patents

Abstract

FIELD: biotechnological methods in waste water treatment.

SUBSTANCE: treatment of waste water containing, in particular, sterically hindered alkylphenols is accomplished by adding strain Pseudomonas aeruginosa XP-25 and biogenic additives. Treatment is conducted in presence of phenol and/or toluene at concentration of sterically hindered alkylphenols, phenol, and toluene not higher than 150, 2000, and 2000 mg/L, respectively, and at weight ratio of alkylphenols to phenol or toluene 150:4000.

EFFECT: improved waste water purification quality and achieved biooxidation of all aromatics for a short period of time.

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Description

The invention relates to biotechnology, namely to biochemical wastewater treatment from phenol-containing compounds containing, in particular, spatially-hindered alkyl phenols.

There is a method of purification of wastewater from phenols by extraction in the presence of hydrocarbons [AC 806616, application 2357297 from 05.10.76], however, this method leads to secondary pollution from exact waters and has high residual phenol values.

A known method of biological treatment of wastewater from phenolic compounds using enzyme preparations isolated from homogenates of plant tissues [AC 939407, application 2966341 from 09.06.80]. The disadvantage of this method is the complexity of the preparation of enzyme preparations by washing the plant tissue homogenate with acetone or rubbing in phosphate buffer.

There is a biological method for purification of wastewater from phenolic compounds using the enzyme preparation o-diphenyl oxidase immobilized on soot [AC 914507, application 2966313 dated 06/11/80], but it only affects the stage of biooxidation of pyrocatechol, which is a metabolite in the intermediate oxidation of phenol by bacterial strains.

A known method of biochemical wastewater treatment from phenols by Botrytis cinerea and Phytoptora infestans fungi [AC 912684, application 2856399 from 12.20.79].

A known method of biochemical wastewater treatment from phenolic compounds at pH 6-8.5 for 1-3 days using a tree-destroying fungus - white rot Polyporus versicolor [AC 969684, application 3277087 from 04/20/81].

A known method of biochemical treatment of pre-diluted wastewater from organic compounds by cultivating Candida yeast microorganisms under aeration conditions followed by separation of microorganisms [AC 975588, application 3006003 from 08/01/80].

It is known the use of strain Pseudomonas aeruginosa No. 28, decomposing phenol [USSR AS No. 499227, application No. 203990 from 01.07.74].

The closest is a method of treating wastewater from phenolic compounds using the bacterial strain Mycobacterium stegmalis VKM B-1205 [AC 1597384, application 4368424 from 10.23.87].

However, the above cleaning methods are time-consuming, time-consuming and provide a low degree of wastewater treatment from phenolic compounds, in particular from spatially hindered alkyl phenols that are difficult to biodegrade, contained, for example, in wastewater from phenolic antioxidant plants.

Wastewater from the production of phenolic antioxidants, for example, CJSC Sterlitamak Petrochemical Plant, contains alkylated spatial-hindered phenols of the following composition,% wt .:

2,6-di-tert-butylphenol - 10-20 phenol - 20-30 phenyl tert-butyl ether - 3-6 2,4-di-tert-butylphenol - 2-4 2-tert-butylphenol - the rest.

The objective of the invention is to improve the quality of wastewater treatment and accelerate the process of biodegradation of spatially hindered alkyl phenols.

The technical result is achieved due to the biochemical treatment of wastewater using the strain Pseudomonas aeruginosa XP-25, in addition, phenol and / or toluene can be added to the effluents of the above composition for faster and better purification, it is possible in wastewater at a concentration of spatially-hindered alkyl phenols , phenol and toluene no more, mg / l: 150: 2000: 2000 respectively or no more, mg / l: 150: 4000 alkyl phenols to phenol or toluene.

Pseudomonas aeruginosa XP-25 strain, previously grown on phenol and adsorbed on activated carbon, is used as an active substrate on activated carbon. The strain Pseudomonas aeruginosa XP-25 was isolated from phenol-contaminated soils of the Sterlitamak Petrochemical Plant by culturing a soil sample in a mineralized environment and subsequent selection of the most active forms. The strain is deposited in the All-Russian Collection of Industrial Microorganisms under the number B-8613, carries out effective biological degradation of aromatic compounds and differs from the known morphological, physiological and cultural characteristics.

Morphological signs. Sticks with a 1-pole flagellum. Gram-negative. They do not form a dispute. In strokes are located singly, in pairs, in short chains.

Cultural signs. Growth on meat-peptone agar in grayish-white colonies with uneven edges. A bluish-green staining of the medium and a characteristic smell of flowering linden were noted. After 18 hours, a uniform turbidity of the medium, the appearance of a thick film on the surface and sediment at the bottom were observed on the meat-peptone broth. The formation of mucus is characteristic.

Physiological signs. Aerob, optimal growth temperature 25-33 ° C, maximum 42 ° C, no growth at 4 ° C.

Biochemical signs. Hydrolyzes gelatin, starch does not hydrolyze. It grows in a purely mineral environment, is not transmitted in growth factors. It utilizes citrate on Simmens' medium; oxidase is positive. It breaks down glucose in a Hugh-Leifson medium under aerobic conditions; under anaerobic conditions, it does not break down lactose and does not form indole.

When fermented on rocking flasks, the strain destroys phenol at a concentration of 1000 mg / l in 4 hours by 99.98%. In a flowing laboratory setup in an immobilized state on activated carbon, the strain oxidizes phenol with a concentration of at least 2500 mg / l in 1 hour.

Cultivation in the laboratory. The phenol-destructive activity of the strain Pseudomonas aeruginosa XP-25 is maintained on a liquid mineralized medium into which phenol is added, for example, of the following composition, g / l:

Phenol - 0.1 KN ₂ PO ₄ - 0.16 Na ₂ HPO ₄ - 0.55 (NH ₄ ) ₂ SO ₄ - 0.50 MgSO ₄ · 7H ₂ O - 0.20 FeSO ₄ · 7H ₂ O - 0.01 CaCl ₂ · 2H ₂ O - 0.01

pH 7.2.

A suspension of bacteria is introduced into the liquid medium by rinsing from the jamb with a small amount of sterile tap water at a rate of 1-3% vol.

The strain is stored on solid agar media at a temperature of + 4 ° C. In the present invention, for easily fouling biofilter with biomass, easily oxidizable aromatic compounds such as phenol and toluene are used.

Adding these compounds allows you to more quickly and efficiently treat wastewater than with separate treatment of spatially hindered alkyl phenols.

Theoretically, this synergistic effect can be explained as follows.

Laboratory studies show differences in specific rates of biomass growth on substrates such as phenol, toluene, alkyl phenols, which for Pseudomonas aeruginosa XP-25 are, respectively: 0.7; 0.58; 0.38 h ^-1 in the case of toluene, and especially phenol, biomass does not require high energy potential to create a double hydroxylating system on the aromatic ring. Non-cyclic intermediates that appear as a result of ortho-splitting of the aromatic structure are included in the normal metabolism of cells, as evidenced by the good biofilter fouling with biomass.

Thus, due to differences in specific growth rates, the phenol and / or toluene system maintains an increased biomass density on the biofilter, thereby facilitating the biodegradation of alkylated phenols with shielded hydroxyl on the aromatic ring.

The method is illustrated by examples.

The content of phenolic compounds and toluene is determined spectrophotometrically in the ultraviolet region (240-400 nm) on a Specord UV-VIS instrument, and a calibration graph is constructed for each substance.

Example 1. A laboratory installation consists of a column filled with activated carbon, operating in a wastewater flow mode. Bottom of the column air is supplied. The strain Pseudomonas aeruginosa XP-25 is immobilized on a sorbent. The ratio of the diameter and height of the column is 1:10. Spatially hindered alkyl phenols of the above composition in a total concentration of 100 mg / l nutrient supplement are fed into the installation. The volumetric flow rate is 1 l / h. After an hour-long retention of wastewater in the biofilter, the concentration of alkyl phenols at the outlet is 2.83 mg / L.

Example 2. The process of de-phenolation is carried out analogously to example 1, but the alkyl phenols are supplied at a concentration of 135 mg / L, and phenol is additionally introduced at a concentration of 1000 mg / L. After an hour-long retention of wastewater in the biofilter, the absence of phenols at the outlet is noted.

Data from other experiments are shown in table 1.

Table 1 Example No. The concentration of compounds at the entrance, mg / l The total concentration of compounds at the exit, mg / l phenol toluene alkyl phenols 3 4000 - 135 1,5 four 1000 1000 137 from 5 2000 2000 135 out 6 - 2000 135 out 7 2500 2500 135 13.8 8 - 4000 150 1,6

Thus, during the bioremediation of phenol-containing wastewater containing, in particular, spatially-hindered alkyl phenols, using the Pseudomonas aeruginosa XP-25 strain and the additional introduction of phenol and / or toluene, together with the effluents, there is an improvement in the quality of wastewater treatment, complete biooxidation all aromatic compounds in a short period of time.

Claims (1)

The method of biochemical wastewater treatment from phenol-containing compounds, in particular from spatially hindered alkyl phenols, by introducing into the medium a strain of aerobic bacteria and biogenic additives, characterized in that the strain Pseudomonas aeruginosa XP-25 VKPM B-8613 and purification are used as a strain of aerobic bacteria lead in the presence of phenol and / or toluene at a concentration of spatially hindered alkyl phenols, phenol and toluene not more than, mg / l: 150: 2000: 2000, respectively, or not more than 150 mg / l of spatially hindered alkyl phenols to 4000 mg / l f nol or toluene.