SU1318542A1 - Method for biological purifying of waste water - Google Patents

Abstract

This invention relates to methods for the biological treatment of wastewater. The purpose of the invention is to increase the oxidizing power of the purification facility and the quality of the purified water by reducing the concentration of activated sludge in it. Purification is performed by feeding raw sewage into the aeration zone of the purification facility and continuously withdrawing the activated sludge from the aeration zone, and purified water from the non-aerated zone. In this case, the particles of active sludge contained in it are continuously removed from the purified water in the non-aerated zone and gradually returned to the aeration zone, for example, by means of pressure flotation. It is recommended to stabilize the output streams of activated sludge and purified water, maintaining their ratio of 1: 4 when the initial wastewater is contaminated according to the BOD of not more than 9 kg centner at wastewater flow rates of 0.1 h increase in proportion to the decrease in pollution and an increase in flow rate up to a flow ratio of 1:17 with contamination of the source water of about 4 kg Oj / M at a flow rate of 0.4 h 1 sludge. 3 tab. (L 00 00 ate

Description

The invention relates to methods for biological wastewater treatment,

The purpose of the invention is to increase the oxide power of the purification facility and the quality of the purified water by reducing the concentration of activated sludge in it.

The drawing shows the scheme of wastewater treatment according to the proposed method.

Example 1. Wastewater with contamination by BIIKj - 5.5 kg

Sh

Oj / m3,

120 m / h are supplied to

15

20

The aeration zone (I) of the vertical purification structure with a volume of 1250 m. In this zone, biological treatment and pre-concentration of the activated sludge is carried out in the generator with the gas-liquid suspension. Excess activated sludge with a suspension concentration of 13 kg / m is removed from the aeration zone of the purification facility at a fixed flow rate of 12 m / h. The treated wastewater from the aeration zone is sent to the non-aerated zone (II), where additional extraction of activated sludge is carried out and returned to the aeration zone. Then, treated wastewater with a sludge concentration of 0.15-0.20 kg / m is removed from the treatment plant at a flow rate of 108. The cost ratio of the concentrated slurry slurry and purified water discharged from the facility to the zone to be cleaned is injected with a working fluid in which air is previously dissolved under pressure. The content of dissolved air in the working fluid does not exceed 5% by volume and, therefore, when it is separated from the working fluid in the pressure flotation zone of the activated sludge (in the pre-recovery zone) biological treatment does not occur — only the physical process of the additional recovery of the sludge takes place. aeration. Purified water is usually used as a working fluid, i.e. The working fluid is an inert air carrier, which is constantly circulating through the zone of active sludge extraction (through non-aerated water), but does not change it with its contamination in terms of VPK /. Therefore, when determining the ratio of flow rates discharged from the purification facility, it is necessary to subtract the flow rate of the working fluid introduced into the non-aerated zone from the value of the flow rate of purified water

The additional extraction of particles 30 of activated sludge from purified water leads to an increase in the activity of the cenoses of activated sludge and to an increase in the oxidizing power, since recoverable and returned to the aeration zone

ki, support equal to 1: 9. Grade 35 activated sludge particles are hour Oj / M table.

BOD5 wastewater treatment is 90%, the oxidizing capacity of the purification facility is 11.0 kg per day (see drawing).

Example. 2. The influence of the parameters of the wastewater treatment process on the degree of their purification at the initial contamination by BOD of 5 kg was studied. The results were tied to 1.

Given in Table. 1, the data indicate a maximum degree of wastewater treatment with a ratio of effluent flows from 1: 4 to J: 17, and with a relatively high degree of contamination of the source water, it is preferable to maintain a ratio ranging from 1: 4 to 1: 9.

Example 3. Additional extraction of activated sludge from purified water in the non-aerated zone of the purification facility is carried out by pressure flotation. At the same time in neae

five

0

The working zone is injected with a working fluid in which air is previously dissolved under pressure. The content of dissolved air in the working fluid does not exceed 5% by volume and, therefore, when it is separated from the working fluid in the pressure flotation zone of the activated sludge (in the pre-recovery zone) biological treatment does not occur — only the physical process of the additional recovery of the sludge takes place. aeration. Purified water is usually used as a working fluid, i.e. The working fluid is an inert air carrier, which is constantly circulating through the zone of active sludge extraction (through non-aerated water), but does not change it with its contamination in terms of VPK /. Therefore, when determining the ratio of flow rates discharged from the purification facility, it is necessary to subtract the flow rate of the working fluid introduced into the non-aerated zone from the value of the flow rate of purified water

The additional extraction of particles 30 of activated sludge from purified water leads to an increase in the activity of the cenoses of activated sludge and to an increase in the oxidizing power, since recoverable and returned to the aeration zone

titsy most young sludge.

A high concentration of activated sludge in the aeration zone is ensured by the removal from the cleaning facility

40 85-95% increase in activated sludge with suspension, the consumption of which is many times less than the consumption of purified water. Creating a gas-liquid suspension and choosing the right ratio

4 output streams provide retention in the aeration zone about 60-80% of activated sludge. The remaining amount of sludge in this zone is provided by additional extraction of particles of sludge in the non-aerated zone and transported to the aeration zone.

In tab. Figure 2 shows the interrelation of the ratios of flows from the cleaning plant, with a value of de55 bits.

The data presented show that the ratio of the output streams of activated sludge to the purified oxide should be in the range from 1: 4 to

31

1:17 to ensure a high degree of purification of highly concentrated wastewater with a BOD of not more than 9 kg O / m. The ratio of flows should be reduced in proportion to the increase in flow rate from 0.1 to 0.4 hours,

In tab. 3 shows the results of a comparison of the proposed and known wastewater treatment methods, showing the advantage of the invention.

Claims (1)

Invention Formula The method of biological treatment of wastewater, by its continuous supply to the aeration zone of the purification facility and the continuous removal of activated sludge from the aeration zone, and purified. The ratio of the activated sludge flow and purified water discharged from the purification facility The degree of purification by VPKs Debit, 10,10,3 0,4 0,4 0,4 The ratio of output streams of activated sludge and purified water is 1: 3 1: 4 1: 9 1:17 1:21 9.0 9.0 5.5 4.0 0.72 0.91 0.90 0.90 2-4 water from the non-aerated zone, characterized in that, in order to increase the oxidizing capacity of the purification facility and improve the quality of the treated water by reducing the concentration of activated sludge in it, and the non-aerated zone extracting activated sludge particles from it and constantly returning them to the aeration zone , for example, by pressure flotation, and the output streams of activated sludge and purified water are stabilized, maintaining their ratio equal to 1: 4 at wastewater discharge rates water 0.1 hours and its contamination is not more than 9 kg and varies in proportion to the flow rate increase to a flow ratio of 1:17 with flow rates of 0.4 hours. , Table 1 1: 3 14 1: 9 1:17 1:23 0.77 0.94 0.90 0.85 0.70 table 2 4.0 0.74 Consumption of incoming waste water, m / h95-100 120 Source wastewater contamination The concentration of activated sludge in the aeration zone kg / m The degree of purification for BOD Oxidative capacity, kg I-12f / v active suspension Cleaning facility exact lvl1 tivniyil I Cleansing Stochiii VOL1 I I I Boldue Compiled by L, Serova . corrector M. Sharoshi order 2473/19;:; TG sub-record of VNIIPI of the USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 .-irvvv. Production and printing company, Uzhgorod, ulGproektn1 7 1318542 Table 3 3-5.1 5.5 2.8-4.1 13 0.66-0.87 0.90 5.7-7.4 11.4 after draining waste . Ooda Working fluid HoiMU4efiue working fluid bozdumn8vVlenyen air