SU649661A1 - Method of biological cleaning of waste water - Google Patents

Description

several times to reduce the return fluid volume.

PRI me R. Industrial effluent hydrolysis-yeast production with an organic content of 5000 mg but the biological oxygen demand (MIC) of the primary sedimentation tanks enter the contact tank, where, simultaneously, the activated sludge supernatant obtained by centrifuging the sludge after the secondary sedimentation tanks is mixed. The amount of pernatant returned with} should be 15; : 100 lg of incoming waste water. In order to reduce the number of returned supernatant, it can be pre-unated at 60-80 ° C to 3-5 m.

After unmixing for 5 minutes

at RP 7.0 and temperature 25 ° С partially

treated wastewater flows together

with the supernatant in the aerotank for further

activated sludge treatment.

After the secondary sedimentation tanks, part of the activated sludge is centrifuged and the resulting activated sludge supernatant is returned to a contact tank for mixing with wastewater.

The dependence of the extraction of organic substances by the apernatant of activated sludge on the mixing time and temperature is presented in Table. 1 and 2.

Table 1

As can be seen from the results of the tests given in table. 1 and 2, the activated sludge supernatant can operate in a wide range of RP environments from 3.0 to 12.0 and temperatures from 20 to 80 ° C, which is explained by the resistance of enzyme systems to high temperatures. The time of contact of the supernatant with the waste water with stirring should be from 2 to 5 minutes; an increase in the unshaking time of more than 5 minutes, as can be seen from the table, does not increase the cleaning effect. Wastewater treatment with an activated sludge supernatant allows for 2–5 min to extract 40–52% of organic wastewater contaminants.

The proposed wastewater treatment method with the activated sludge supernatant reduces the volume of aeration tanks by about 2 times due to a decrease in the amount of contaminants in the first phase of the treatment by 40-50%. Operating costs are reduced due to the fact that 40-50% of contaminants

table 2

are removed without air consumption for this process due to only mechanical mixing of the wastewater with the activated sludge supernatant.

The process of biological wastewater treatment is intensified by reducing the total time required for wastewater treatment, as well as by deeper and faster removal of suspended solids. The wide temperature range in which the process can take place allows the use of wastewater without preheating or cooling.

A wide pH range avoids the cost of chemicals for providing a certain pH of the medium.

Claims (2)

Invention Formula The method of biological wastewater treatment, which includes treatment with activated sludge in aerotanks, followed by separation of water from sediment in settling tanks, which, in order to increase and reduce the treatment time and simplify the process, wastewater before treatment in aerotanks d oupernatant activated sludge and stirred at a temperature of 20-80 ° C, pH 3.0-12.0 for 2-5 minutes. 6 Sources of information taken into account in the examination: 1. "Water supply, sewerage, hydraulic structures. Rep. Intermediate scientific and technical Sat, 1976, vol. 19, p. 45-48. 2. USSR author's certificate number 170418, cl. C 02 L 1/02, 1960.