SU1758026A1 - Method of cleaning ore concentration sewage from suspended matter - Google Patents

Abstract

Usage: in biotechnology, namely in the methods of processing wastewater from mining and chemical industries. The essence of the invention: wastewater from the processes of enrichment of mining and chemical ores (phosphoric and boric silicate), is de-suspended by adding Aureobasidium pullulans BKMF culture liquid as a coagulant. 1116 containing cells and exopolysaccharides. The process is conducted at a pH of 6-8, created by carbon dioxide. When settling for 1 hour, the solids content in water is reduced by 98.8%, a dense precipitate of the solid phase is obtained. 5 tab.

Description

The invention relates to wastewater treatment and can be used in plants that process mining and chemical ores.

The purpose of the invention is to increase the degree of purification from suspended solids and to obtain a solid residue during the treatment of wastewater from the processes of carbonization ores.

As a reagent, Aureobasidium pullulans BKMF-1116 containing biomass of exopolysaccharides is used in an amount of 2–20 mg / l on a dry basis at a pH of 6–8 effluents created by carbon dioxide. Biomass is pre-grown on the medium of the following composition, g / l: sucrose 10-15; (NN4) 2804 1-1.5; MgS04 0.05-0.1; K2HP04 1-1.5 at pH 7-7.5, the medium is sterilized at 0.5 ± 0.01 atm for 30 min, the cultivation is carried out on

rocking chair (280 rpm) for 3-5 days, sucrose can be replaced in the medium with a cheap substrate, for example, wood hydrolyzate.

coagulant reagent uses a culture fluid containing cells and exopolysaccharides A. pullulans

The sedimentation of suspended particles is carried out by sequential treatment of wastewaters of concentrating plants with carbon dioxide to pH 6-8, and then with biomass of microorganisms, followed by separation of the sediment from the clarified layer using traditional methods in a gravitational field on various types of settling tanks or in a centrifugal field, for example, in centrifuges. As a result of processing by this method, wastewater clarification is achieved up to 98.8%, with the formation of dense

SP 00

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solid sediment, the volume of which ranges from 6 to 17 vol. %

When the biomass concentration is higher than 20 mg / l, the sedimentation and compaction rate of the sediment does not increase, and when the biomass concentration is less than 2 mg / l, the sedimentation rate decreases and the content of suspended particles Ъ of clarified water increases.

At pH values above 8, it is not observed with sedimentation of weight at various expenses of biomes. A pH banner below 6 is not reached by supplying carbon dioxide to the pulp of mining chemical ores, since carbon dioxide is related to weak acids, and mining chemical ores are in contact with water create a weakly alkaline medium with a pH of 7.8-8.5. After enrichment, the wastewater has a pH of 8.5-10. The coagulating effect of A. pullulans on suspended sewage is due to the polulaccharide pullulan formed by this culture, the polymeric molecules of which, when introduced into wastewater with suspended particles, act as coagulants at pH 6–8 set by passing COj.

The experiments were carried out on wastewater from washing of clay phosphate ores (PFC), drains from the flotation of phosphate-carbonate ores (PFR) and drains of flotation of boric silicate-carbonate ores (FBI). Characteristics of wastewater, subjected to purification from suspended particles, are presented in Table. 1. Initially, the drains of all these processes are subjected to the removal of large particles + 0.037 mm by the method of classification.

The process of sewage purification from suspension is evaluated according to the following parameters: sedimentation rate of suspended substances V, m / h, the content of suspended substances in the clarified layer C, mg / l; the degree of purification To,%, the amount of sedimentation solid phase Q,% (of the total volume of waste water), where

The settled amount of suspended substances, g

K Initial amount of suspended substances, g 100%.

In all examples, the process is carried out at a constant temperature of 22 ± 1 ° C. The constant time of precipitation is 1 hour of the indicated production effluent. Measurements are made in cylinders with a capacity of 100 ml with the definition of the height of the clarified layer in dynamics. After 1 h, the clarified water is decanted, the solid content of the clarified water and the volume of sediment are determined.

Examples 1-7, The effluent of PFR is treated sequentially with CO2-gas to pH 7.3, then with the biomass of microorganisms A. pullulans in the amount of 1, 2, 5, 10, 15, 20, 21 mg / l of effluent. The results are presented in table. 2, proposed examples 1-7.

Example 8, Wastewater PFR treated by a known method with sulfuric acid to a pH of 7.3. The results are presented in table. 2, example 8.

In tab. Figure 2 shows the effect of biomass concentration on the precipitation of a suspension of PFR at pH 7.3, created by carbon dioxide.

From the data table. 2, it can be seen that a positive effect is observed at a biomass concentration of 2–20 mg / l; a further increase in dosage does not improve the deposition efficiency.

The reverse order of the supply of C02 and biomass or the effect of each of them separately do not give an effect.

In tab. Figure 3 shows the effect of different orders for the supply of COA (pH 7.3) and biomass (dosage 10 mg / l) and their individual supply from the sedimentation of PFR wastewater,

Sequential supply of CO and then biomass due to the formation of large aggregates of particles leads to an increase in the rate of their sedimentation, the degree of clarification of water and compaction of the sediment.

In tab. 4-the results of the sedimentation of sewage suspension by PFR biomass (dosage 10 mg / l) depending on the pH values created by carbon dioxide are given.

The data table. 4 show that optimal precipitation results are achieved at pH (8-8). Lower pH values of the slurry of clay slurries are not achieved with a supply of carbon dioxide.

The proposed method precipitates suspended substances from the sewage of the processes of flotation of phosphate-carbonate ores (FFR) and flotation of boric silicate-carbonate ores (FBI). Carbon dioxide is fed to a slurry pH of 7.3; biomass consumption is 10 mg / l. The results of the experiments are given in table. five.

The sewage of the flotation processes of carbonated phosphate and boron ores (PFR and FBI) is effectively clarified by the proposed method. The known method does not give positive results, which is explained by the high alkalinity of the effluent and the strong peptization of thin sludge under conditions of dissolution of carbonates with sulfuric acid.

Other types of bacteria, which also form polysaccharides, when applied to precipitate sludge carbonated feedstock at a pH of 6 to 8, set by transmission of C02, have the opposite effect.

effect - increase suspension stability and stabilize the system.

The application of this method allows, firstly, to increase the degree of clarification of wastewater from the processes of washing and flotation of mining and chemical ores by 1.5 times and reach 99% of purification; secondly, to obtain a dense sediment of the solid phase, and also to exclude from the formulation of coagulants cepnyto acid, which is a source of environmental pollution.

As a C02 gas, flue gases of boiler plants, drying furnaces and roasting plants that process limestone raw materials can be used, which ensures the disposal of harmful emissions.

Claims (1)

Invention Formula The method of purification from suspended substances of wastewater from the processes of enrichment of ores, which includes treatment with a reagent, characterized in that, in order to increase the degree of purification from suspended substances and to obtain a solid residue during the treatment of wastewater from the processes of enrichment of carbonacetized ores, dyes biomass Aureobasldlum pullutans BKMF-1116 in the amount of 2-20 mg / l dry matter at pH 6-8, created by carbon dioxide. Table 1 20 Table 2 Table3 Table A Table 5