SU889631A1 - Method of biological treatment of waste water - Google Patents

Description

(54) METHOD OF BIOLOGICAL TREATMENT OF WASTEWATER

The invention relates to a communal JHOMy household primarily for the purification of domestic faecal waste liquid. A known method of pre-aerobic treatment of wastewater in a pre-aerator, followed by settling in a horizontal sump 1. The disadvantage of this method is that the aerobic pretreatment in an aerator lasts 10-20 minutes and therefore is ineffective. The known method of anaerobic treatment of sediment in septic tanks, in which effective retention and partial digestion of sediment occurs. 2 The disadvantage of this method is the poor performance of septic tanks, in addition, the outgoing water acquires a hydrogen sulfide odor, which makes it difficult to clean it further. The closest in technical essence and the achieved result to the proposed is the method of biological treatment of wastewater with bi-coagulation. The biocoagulation process is carried out in a special chamber in which a mixture of waste water and constantly activated sludge is aerated for 20 minutes. The chamber is combined with a settling tank and the mixture processed in it continuously enters the settling tank, where precipitating particles 3 precipitate out. The disadvantages of this method are the need for continuous introduction of activated sludge, short aeration, deterioration of the quality of primary sediment due to the addition of active sludge, the need sludge treatment sites for sludge treatment. The purpose of the invention is to increase the degree of water purification and the quality of the precipitate formed. The goal is achieved by the fact that in the method of biological treatment of wastewater, including aerobic

the treatment of the sun, dy, water and sediment is simultaneously subjected to anaerobic treatment in a single container, divided into upper aerobic and lower anaerobic zones with the ratio of the heights of these zones 1: 2.5-3.5 and aeration at the boundary of these zones.

Fig, 1 shows a settling tank, top view; in fig. 2 - the same, side view.

The device includes a container 1, pipeline 2, section 3, pipelines of pneumatic aeration 4.

The capacity is divided by the aeration system into two zones - upper aerobic and lower anaerobic, the ratio of the heights of these zones is 1: 2.5-3.5. Due to this, the particles capable of settling remain in the lower anaerobic zone and gradually move to the bottom, forming a weighted filter in the anaerobic zone, the particles that have reached the bottom form a sediment layer. In the upper zone, aerobic conditions are created and decomposition of the contaminants is produced by aerobic microorganisms. Facultative anaerobic processes occur optional by anaerobic microorganisms (i.e. microorganisms capable of decomposing organic substances with very small dissolved oxygen concentrations. Below this zone are layers of liquid and sediment in which the decomposition of organic substances (dissolved and solid) was Anaerobic and aerobic bacteria in the process of vital activity substances that mutually stimulate the metabolism, and therefore the performance of these two groups of microorganisms. Due to the presence of anaerobic and aerobic bacteria in the same container, these substances are in the liquid and increase efficiency decomposition of organic substances by both groups of bacteria. Fermentation is accompanied by the release from the decomposable sediment of fermentation gases and a certain amount of dissolved x organic acids, which helps reduce the sediment layer.

Sediment decomposition is a function of the diffusion of half-life products in the upper water layers, where the products are finally decomposed. In the absence or very weak movement of the seat

The rate of decomposition of the sediment is limited by the speed of molecular diddefusion and the decomposition of 10–20% of the sediment occurs. Falling stream of incoming flow

creates an initial impetus for fluid movement, a narrow space contributes to the preservation of a certain speed, and the aspiration to the outlet allows you to maintain an optimal speed

fluid movement throughout the journey. The newly suspended suspended substances are transfused by anaerobic microorganisms and are involved in the process of anaerobic digestion. Thanks

5 Constantly occurring fermentation and natural compaction processes, the sediment volume is reduced by 40%. This increases the period of operation of the structure without removing the accumulated sediment. Fermentation improves sludge quality,

allowing it to be used as a fertilizer. Organic matter dissolved in a layer of water above the sediment is also decomposed anaerobically to gaseous products. The upper layer of fluid is constantly aerated and aerobic decomposition of dissolved and solid organic substances takes place in it, carried out by aerobic microorganisms. In the aerobic zone, the oxidation of fermentation gases, rising from the anaerobic zone, also occurs.

At the same time, under the influence of artificial aeration, coagulation (sticking) of the smallest particles of suspended substances occurs, which contributes to their sedimentation. These cohesive particles, the passage through the bottom layer - a weighted filter, coalesce with the particles found on the sedimentation path and entrap them into the sediment.

Example. A waste liquid containing 400 mg / l of suspended particles of different sizes and BPKg 150 mg / l is supplied to tank 1 via pipeline 2. The residence time of the waste fluid in the tank is 1.5-2 hours. After aerobic-anaerobic treatment, the output ratio Cheat 200 mg / l suspended particles

and BPKs- 115 mg / l. The sediment consists of particles that have undergone aerobic and anaerobic decomposition. Due to this, its amount decreased by 40% compared to the original. Besides

In addition, the minerals contained in the sediment and are fertilizers are becoming more accessible to plants, since complex organic

substances decomposed. The introduction of fermented sediment into the soil does not cause a deficiency of oxygen in it, as it occurs when a raw sludge is introduced; the sediment becomes sanitary.

The proposed method avoids the adaptation process of cleaning organisms in the sewage treatment plant, which receives the drain from the tank, which reduces the cleaning time by. 10% and increases the efficiency of the facility. Pretreatment of the sludge by the proposed method allows to obtain a sludge prepared for further recycling as fertilizer. In addition, during fermentation, its amount decreases by A0%.

Due to the aeration of the upper layer of liquid, no unpleasant odors are released, which is always observed when septic tanks and anaerobic ponds work.

Continuous excitement on the surface of the liquid, caused by artificial aeration, prevents the formation of a crust from floating clods of sediment, breaks these clods into small particles, which contributes to their further oxidation under aerobic conditions or subsidence, which improves the quality of the outgoing water.

The proposed method of prediaritelny treatment of waste liquid and sediment saves equal to the cost of construction and operation of the pre-aerator and sludge beds; their function is performed by the capacity in which the proposed method is carried out.

Claims (3)

1. Zhukov A.I. and others. Sewage M., Stroyizdat, 1975, p. 260 2. In the same place 269. 3. Postnikov I.S., Tsitovich S.I., Tugusheva N.I. Pre-treatment of waste liquid by biocoagulation. M., publishing house MJU RSFSR, .1958. SL Je u 3t Jb uu uu Csj