RU2467959C2 - Method of launching biological treatment plants - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method of launching biological treatment plants involves feeding waste water into an aeration tank and biocenosis culturing in aeration conditions. Biocenosis culturing is carried out with continuous aeration for 36-48 hours with 0.5-1.0 m³/h of air per 1 m³ of the aeration tank of the portion of clarified household wastes with addition of biologically active nitrogen and phosphorus compounds BOD₅:N:P=100:1:0.5. Adaptogen is simultaneously added with gradual growing, in 36-48 hours, in the wastes being treated of a given concentration of the reference component contained in adaptogen from 0 to 5*10⁴ maximum allowable concentration (MAC).

EFFECT: invention provides faster launching of biological treatment plants, cuts the time for growing biocenosis; treatment of clarified household wastes begins after 5 days.

3 cl, 1 tbl, 1 ex

Description

The invention relates to the field of biochemical wastewater treatment and can be used to accelerate the launch of treatment facilities, including those temporarily inactive, and their adaptation to specific pollutants of industrial wastewater in new working conditions.

A known method of biological wastewater treatment in aeration tank using activated sludge and a biostimulant, which is used as an extract of excess activated sludge (USSR AS No. 546568, class C02C 5/10).

The disadvantage of this method is the low rate of formation of biomass in wastewater treatment plants, with non-specific composition, high complexity and the impossibility of targeted regulation of the efficiency of wastewater treatment.

The closest method adopted for the prototype is a method of cultivating the biocenosis of activated sludge under the conditions of an aerobic biological process by continuous aeration of wastewater with air (USSR AS No. 1574546, class C02F 3/34).

The disadvantage of this method is the impossibility of directional regulation of the effectiveness of wastewater treatment, because the process is uncontrollable and largely depends on external random conditions. The disadvantages of this method also include the high complexity and a long period of output of treatment facilities to the regime. In addition, the disadvantage of this method is the one-sided orientation of the formed biomass to natural organic pollutants, which leads to the unpreparedness of treatment plants for receiving real industrial wastewater. This is due to the fact that in nature there are no microorganisms whose nutrition is specialized in synthetic products of industrial chemistry.

The objective of the invention is the accelerated launch of biological treatment plants prepared for changing working conditions - adaptation of working biomass to potential industrial pollutants, reducing the time of building up specialized activated sludge.

The problem is solved in that the emerging biocenosis of temporarily inactive biological treatment plants is simultaneously (synchronously) supplied with oxygen, nutrient-biogenic products and an adaptogen. Sources of carbon, nitrogen and phosphorus are used as nutrient-biogenic products. As an adaptogen, mixtures of the main pollutants of industrial wastewater are used that do not have direct analogues in natural conditions. The biomass of conventional wastewater treatment plants is not adapted to the processing of such contaminants. The introduction of these wastewaters into standard biological wastewater treatment plants (based on the prototype) leads to the suppression of the activity of active biomass and requires a long period (from 12 to 15 days) of its rehabilitation and adaptation to such pollutants. At the same time, the supply of insufficient quantities of adaptogen does not give positive results, since the growth of specialized biomass is inhibited by biomass, which is used to feeding on household waste components. Therefore, the processes of adaptation and growth of specialized biomass must be mutually agreed.

The proposed method is as follows.

In one section of an aeration tank with a volume of 500 m ³ - 2000 m ^3, clarified household wastewater is pumped, biologically active additives, a model pollutant of industrial wastewater are introduced into them, to receive which these biological treatment facilities (adaptogen) are prepared, and this mixture is subjected to continuous aeration in mode from 0.5 to 1.0 m ³ / hour for 1 m ³ waste water in the aeration tank for 36-48 hours (adaptation period). The source of carbon for growing biomass is the organic pollution of the natural origin of domestic wastewater. As biologically active additives, nitrogen and phosphorus compounds are used, for example, ammonium sulfate and sodium phosphate, which are added to waste water in the ratio of BOD ₅ : N: P = 100: 1: 0.5. As an adaptogen, clarified industrial effluents are used, for the reception of which these biological treatment plants or an artificially prepared solution containing potential pollutants are prepared. This solution should correspond to the composition of real industrial wastewater and preferably contain the same type of components from which the main (reference) component is selected, according to which the wastewater quality control will be carried out. For enterprises of a chemical profile - of the type “chemical fiber”, caprolactam having a maximum concentration limit of 0.01 mg / l, or formaldehyde having a maximum concentration level of 0.1 mg / l, or a similar compound, can be used as a reference component, depending on the particular production. For wastewater of petrochemical industry enterprises, the reference component can be used, for example, petroleum products with MPC = 0.05 mg / l.

Adaptogen is supplied to the aeration tank at an average speed of 200 to 1100 MPC / h, where MPC is the value of maximum permissible concentrations of harmful substances (reference component) in the waters of fishery water bodies.

In this case, the set (received) concentration of pollutants in the aeration tank during the adaptation period varies from 0 to 5.5 * 10 ⁴ MPC. After 36-48 hours, the adaptation of biological treatment facilities to industrial wastewater is completed and these facilities are brought to full operation by continuous aeration for 60-72 hours in a volume of 1.0 to 1.5 m ³ / h per 1 m ^{3 of} wastewater in aeration tank. During this time (60-72 hours), specialized biomass accumulates and the treatment plant can begin to work at full real load.

Example

One section of the aeration tank with a volume of 500 m ³ for 4/5 of the volume is filled with clarified household wastewater from the urban sewage system with a BOD of ₅ equal to 580 mgO ₂ / l. 10.9 kg of ammonium sulfate and 6.1 kg of sodium phosphate are added to the aeration tank. Include aeration in the mode of 200 m ³ / hour. At the same time, in small portions, preconcentrated washings of the production of nylon synthetic fiber (adaptogen) are introduced. The concentration of the reference component (caprolactam) in the adaptogen is equal to 2500 mg / l. The first portion is 2.1 m ^{3 of} adaptogen. Then every hour over a period of 48 hours add 2.1 m ³ adaptogen. After 48 hours (adaptation period), the second section of the aeration tank is filled with clarified household wastewater from the city sewer and is “looped” with the first section. Include aeration on the entire aeration tank in the mode of 1500 m ³ / hour. 72 hours after the adaptation period (120 hours from the start of work), the treatment plant goes into operation. The concentration of specialized active biomass increases to 4-6 g / l, and the concentration of pollutants (controlled by caprolactam) decreases below the MPC. The results of the biological treatment facilities are summarized in table.

Table The change in the concentration of caprolactam in aeration tank over time Time hour The introduced concentration, mg / l Actual concentration (Sfact), mg / l Sfakt / MPC one 13.1 13.1 1310 12 148.2 97.2 9720 24 279.8 165.5 16550 36 397.4 216.0 21600 48 503.2 238 23800 49 251.8 118.6 11860 72 251.8 40.6 406 120 251.8 0.01 1,0

Thus, a full exit to the treatment mode of industrial effluents from atypical pollutants is carried out in 5 days, while the prototype this period is from 12 to 15 days.

Claims (3)

1. The method of launching biological treatment plants, including the supply of wastewater to the aeration tank, cultivating the biocenosis under aeration conditions, characterized in that the cultivation of the biocenosis under aeration conditions is carried out by continuous aeration for 36-48 hours in the mode of 0.5-1.0 m ³ / h of air per 1 m ³ aeration tank of a portion of clarified household wastewater with the addition of biologically active nitrogen and phosphorus compounds to them at a BOD ratio of ₅ : N: P = 100: 1: 0.5 and with the simultaneous addition of an adaptogen to them with gradual , for 36-48 hours, increase In the treated effluents, the preset concentration of the reference component contained in the adaptogen is from 0 to 5 · 10 ⁴ MPC. 2. The method of starting biological treatment plants according to claim 1, characterized in that pre-concentrated flushing effluents from the production of synthetic nylon fiber are used as adaptogen. 3. The method of starting a biological treatment plant according to claim 1, characterized in that caprolactam is used as the reference component contained in the adaptogen.