SU688444A1 - Method of purifying surface water - Google Patents

Description

compacted to a moisture content of 90-98%.

The introduction of aerobic stabilized sludge into the surface waters ensures the effective release of suspended solids upon subsequent sedimentation. The resulting sediment, represented by mineral water impurities and stabilized sludge, is safe in sanitary conditions and, in addition to dehydration, does not require additional treatment. The subsequent aeration of the settling runoff in a mixture with excess activated sludge ensures removal of dissolved organic impurities after a short contact, and the treatment of the separated sludge does not require special facilities, as it is carried out in the mineralizer, which is included in the household and / or or industrial wastewater.

Displacement of water with biologically treated chlorinated household and / or industrial wastewater provides its disinfection due to excess chlorine, which is not present in chlorinated water.

Pre-compaction of stabilized sludge allows the dry matter to be provided in surface water with a dry matter without simultaneously increasing the flow rate of the mixture passing through the facilities that are designed for water purification. In addition, compaction of stabilized sludge reduces the supply of contaminating impurities with sludge water in the form of sludge metabolism products.

The method is carried out as follows. Surface water (rainwater and meltwater) is freed from sand in the sand trap, then compacted stabilized sludge is introduced from the mineralizer. The mixture is stirred in a mixer and underwent separation in a settling tank. The precipitate is separated and sent to dewatering, and activated sludge is introduced into the water and aerated in containers, settled in a sump, removed and mixed with biologically purified chlorinated household and / or industrial wastewater. Sludge from secondary settlers is supplied to the mineralizer. Purified water can be discharged into the reservoir or used again for technical water supply.

Example. Contaminated surface runoff from the municipal drainage basin (suspended matter content is 1800 mg / l, VPK-175 mgOa / l, with a titer of 0.00005) with an estimated consumption of 2.5 is diverted to the city station, where facilities for cleaning rainwater and melt water. The effluent is directed to a sand-catcher, and then to an aerated mixer, which is designed for a 10-minute stay of wastewater. Before the mixer, aerobic stabilized and partially dehydrated (solid content 90 g / l) sludge in an amount of

its content in the mixture is in the range of 2-5 g / l (0.057-0.088). The mixture of wastewater and sludge, and after displacement, is sent to sedimentation tanks, calculated for a 30-minute discharge of the estimated wastewater flow.

waters The sediment deposited in the sediments is diverted to sludge and sites, and the clarified water (suspended matter - mg / l PO, VPK 39 mgOg / l) - to a tank with aeration designed for two-hour wastewater discharge. Before this tank, excess activated sludge is introduced into the stock, ensuring its concentration in the mixture within the range of 15-25 g / l over the dry season. Proaeropania with active

Sludge water is sent to the sumps with a 1.5-hour stay. The sediment from the settling tanks is diverted to a mineralizer designed to aerobically stabilize excess activated sludge from aerotanks.

for urban wastewater treatment. The clarified waste water (suspension content 17 mg / l, MIC 12 mg Og / l, if the titer is 0.0005) is mixed for disinfection with chlorinated biologically purified

municipal wastewater containing about 1.5 mg / l of residual active chlorine, and then discharged into the reservoir.

Compare the proposed and known

The procedure shows that, according to a known method, the processing time of the first portions of the runoff in the aeration tank is compatible with household wastewater in the continuous aeration mode — about 10 hours, besides, the settling time in the nervous and secondary septic tanks is about 3 hours. An even longer residence time (3 days and more) requires aeration of low-concentration portions of the runoff in contact aerated accumulators (by analogy with high-load aerated bioiruds).

According to the proposed method, the total treatment time of the flow in all structures is about 4 hours (an aerated flow mixer with stabilized sludge is 15 minutes; a settling tank for separating precipitated substances and stabilized sludge is 30 minutes; an aerated capacity for a flow mixture with excess active sludge is 120 minutes; sump dl

separation of excess activated sludge - 90 min).

When compaction of the sludge before being fed into the drain to a humidity of 90% (the concentration is increased to 100 g / l), its required

the volume is reduced by about 15 times to provide the necessary concentration of active sludge in the mixture. As a result, the volume of the aerated mixture is reduced from 150 to 103% of the flow rate and surface

the drainage and, accordingly, the capacity of the aeration facilities and settling tanks are reduced.

Claims (4)

1. A method for purifying surface water, which includes treatment with activated sludge, settling, separating sediment, characterized in that, in order to reduce the duration of purification, aerobically stabilized sludge is introduced into the water, the mixture is settled, the sediment is dehydrated, and the clarified water is introduced excess activated sludge is aerated, then again settled, while sediment is fed for mineralization, and water is shifted with biologically purified and chlorinated household and / or industrial wastewater. 2. A method according to claim 1, characterized in that the surface waters are transported with stabilized sludge for 5-15 minutes and set aside for 30-60 minutes. 3. Method according to paragraphs. 1 and 2, characterized in that the clarified water is aired with excess activated sludge for 30–120 min. 4. Method according to paragraphs. 1 and 3, I differ by the fact that, in order to reduce the size of the sewage treatment plant, aerobically stabilized sludge is compacted to 90-98% moisture before being introduced into surface water. Sources of information taken into account in the examination 1.Shigorin GG Obnosilavia sewage system. M., “HIC RSFSR, 1960, p. 157-158. 2. Authors' certificate, the letter of the USSR N ° 437719, cl. C 02 C 1/06, 1974.