RU2312073C1 - Process for biosorption purification of effluents to remove heavy metal ions - Google Patents

Abstract

FIELD: waste water treatment processes.

SUBSTANCE: invention is aiming at removing heavy metal ions from effluents coming from food industry enterprises. Process comprises providing nutrient medium, culturing strain Streptomyces chromogenus s.g. 0832, adding biomass with cultural liquid to effluent at ratio 1:5.0, mixing, and sedimentation. Nutrient medium contains: starch, soy bean flour, ground feathers, zinc sulfate, ferrous sulfate, calcium sulfate, potassium hydroorthophosphate, and water. Starting pH value is 11.0±0.2. Nutrient medium is inoculated with water-spore slurry of above-named strain in amount 1 vol % and cultured at aeration fro 72 h at 28±1°C.

EFFECT: enabled most complete removal of heavy metal ions for a short time period.

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Description

The invention relates to methods for wastewater treatment of food industry enterprises, in particular meat processing plants, by the biosorption method from heavy metal ions.

The closest in technical essence and the achieved effect is a method in which the authors proposed to use the biomass of the microorganism Saccharomyces cerevisiae to extract ions of nickel (Ni ²⁺ ), copper (Cu ²⁺ ) and lead (Pb ²⁺ ) from water [Mihova St., Godjevargova T. Biosorption of heavy metals from aqueous solutions, 2000, 1].

The disadvantages of the prototype are the low efficiency of the extraction of heavy metal ions, the inability to extract iron ions, the duration of the cleaning process.

An object of the invention is the use of bioflocculating agents for wastewater treatment from heavy metal ions, increasing the efficiency of wastewater treatment in meat plants using a bioflocculating agent based on the microorganism Streptomyces chromogenes s.g. 0832, the intensification of the cleaning process and increasing its profitability, reducing the cost of the cleaning process.

The technical problem is achieved by the fact that in the method of biosorption treatment of wastewater from heavy metal ions, which involves preparing a nutrient medium containing starch, zinc sulfate, iron (II) sulfate, calcium carbonate, potassium hydrogen phosphate and water, cultivating microorganisms, introducing biomass of microorganisms into waste water, mixing, sedimentation, new is that the nutrient medium additionally contains soy flour and crushed feather, in the following ratio, wt.%:

starch - 5.0

soy flour - 0.5

chopped feather - 1.0

zinc sulfate - 0.02

iron (II) sulfate - 0.01

calcium carbonate - 0.4

potassium hydrogen phosphate - 0.08

water - the rest

the initial pH of the medium is maintained at 11.0 ± 0.2, the resulting culture medium is inoculated with an aqueous-spore suspension of the strain Streptomyces chromogenes s.g. 0832 in the amount of 1% by volume of the nutrient medium, cultured by aeration for 72 hours at 28 ± 1 ° C, after which the culture fluid together with the biomass is introduced into the wastewater, while the volumetric ratio of the culture fluid and biomass to wastewater is 1: 5.0.

The technical result consists in increasing the efficiency of wastewater treatment from heavy metal ions, intensification of the purification process and increasing its profitability.

The method is as follows.

Pure culture of Streptomyces chromogenes s.g. 0832 grown on an agarized nutrient medium composition (wt.%): Ammonium sulfate - 1.0; potassium hydrogen phosphate - 1.0; magnesium sulfate - 1.0; calcium carbonate - 3.0; sodium chloride - 1.0; starch - 17.0; agar - 20.0; the rest is water, the initial pH of 7.2 for 3-4 days at a temperature of 28 ± 1 ° C.

The following components are used for the deep cultivation of the strain: starch - 5.0 wt.%; zinc sulfate ZnSO ₄ - 0.02 wt.%; iron (II) sulfate FeSO ₄ - 0.01 wt.%; calcium carbonate CaCO ₃ - 0.4 wt.%; potassium hydrogen phosphate K ₂ HPO ₄ - 0.08 wt.% and additionally soy flour - 0.5 wt.% and crushed feather - 1.0 wt.%; the rest is water, the initial pH of the medium is 11.0 ± 0.2.

The prepared culture medium containing starch, soy flour, feather, zinc sulfate, iron (II) sulfate, calcium carbonate, potassium hydrogen phosphate and water, is inoculated with strain Streptomyces chromogenes s.g. 0832 and cultured by aeration for 72 hours at a pH of 11.0 ± 0.2; temperature 28 ± 1 ° С.

After the cultivation of the strain Streptomyces chromogenes s.g. 0832, culture fluid and biomass are introduced into the wastewater in a volume ratio of 1: 5.0. Next, stirring is performed for 10-15 minutes, which promotes active flocculation. During this time, a sorption purification process occurs, accompanied by active flocculation, sedimentation of flocs and, as a consequence, clarification of the runoff, as well as effective removal of iron, copper, lead and nickel ions.

The method of biosorption wastewater treatment from heavy metal ions is illustrated by examples.

Example 1. Prepare a nutrient medium of the following composition, wt.%:

starch - 5.0

soy flour - 0.5

chopped feather - 1.0

zinc sulfate - 0.02

iron (II) sulfate - 0.01

calcium carbonate - 0.4

potassium hydrogen phosphate - 0.08

water - the rest

the initial pH is adjusted to 11.0.

In Erlenmeyer flasks with a capacity of 750 cm ³ contribute 100 cm ³ nutrient medium. The medium is inoculated with an aqueous-spore suspension of a strain of Streptomyces chromogenes sg 0832 in an amount of 1% by volume of the medium. An aqueous-spore suspension of the strain Streptomyces chromogenes sg 0832 is prepared as follows: a bevel of a 4-day culture in 18 × 180 mm test tubes is filled with 10 cm ^{3 of} sterile water and the spores are washed off. The strain Streptomyces chromogenes sg 0832 is incubated on a rocking chair at a speed of 1.7-1.8 s ^-1 , temperature (28 ± 1) ° С for 72 hours.

After the cultivation of the strain Streptomyces chromogenes s.g. 0832, culture fluid and biomass are introduced into the wastewater in a volume ratio of 1: 5.0. Mixing is then carried out for 10 minutes. During this time, a sorption purification process takes place. Data analysis of indicators of the effectiveness of wastewater treatment are presented in table 1.

Example 2. Prepare a nutrient medium, carry out the cultivation of the producer: preparation of spore suspension, inoculation of seed, cultivation is carried out analogously to example 1.

After the cultivation of the strain Streptomyces chromogenes s.g. 0832, culture fluid and biomass are introduced into the wastewater in a volume ratio of 1: 5.0. Then stirring is carried out for 15 minutes. During this time, a sorption purification process takes place. The cleaning results are presented in table 1.

Table 1 Indicators The control Indicators for Examples one 2 The concentration of Ni ²⁺ , mg / g 0.468 0.689 0.512 The concentration of Cu ²⁺ , mg / g 0.246 1,321 0.956 The concentration of Pb ²⁺ mg / g 1,146 1,987 1,213 The concentration of Fe ²⁺ + Fe ³⁺ , mg / g - 2,312 1,945

The proposed method for treating wastewater from heavy metal ions makes it possible to most completely remove heavy metal ions from wastewater of food industry enterprises, in particular meat processing plants, providing a high degree of extraction in a short period of time.

Claims (1)

A method of biosorption treatment of wastewater from heavy metal ions, which involves preparing a nutrient medium, cultivating microorganisms, introducing biomass of microorganisms into wastewater, mixing, sedimentation, characterized in that the nutrient medium contains starch, soy flour, ground feather, zinc sulfate, iron sulfate ( II), calcium carbonate, potassium hydrogen phosphate and water in the following ratio of components, wt.%: starch 5,0 soy flour 0.5 chopped feather 1,0 zinc sulfate 0.02 iron (II) sulfate 0.01 calcium carbonate 0.4 potassium hydrogenorthophosphate 0.08 water rest the initial pH of the medium is maintained at 11.0 ± 0.2, the resulting culture medium is inoculated with an aqueous-spore suspension of the strain Streptomyces chromogenes s.g. 0832 in the amount of 1% of the volume of the nutrient medium, cultured by aeration for 72 hours at (28 ± 1) ° С, after which the culture fluid together with the biomass is introduced into the wastewater, while the volumetric ratio of the culture fluid and biomass to wastewater is 1: 5.0.