The flocculation reaction zone of the high-efficiency sedimentation tank is composed of a rapid stirring zone and a non-stirring zone: the rapid stirring zone is controlled by an adjustable-speed impeller to control the mixing speed of the mixed water after the drug is added; the non-stirring zone can promote the increase of alum flowers and make alum flowers dense Evenly. The sewage in the flocculation reaction zone forms a high-concentration suspended sludge layer under the action of coagulant and reflux sludge to increase the chance of particle collision, and effectively adsorbs pollutants such as colloids, suspended matter, emulsified oil, COD and metal ions. Sludge backflow not only saves the dosage of chemicals, but also maintains the concentration of suspended solids in the reaction zone at the optimal level, thereby achieving the purpose of optimizing the flocculation reaction.

Working principle

After the sewage after the flocculation reaction enters a large area of pre-settlement concentration area, most of the solid suspended solids settle and concentrate in this area. Part of the sludge returned, and the remaining sludge was scraped into the mud hopper by the scraper at the bottom of the concentration area, and was sent to the mud treatment system by the sludge discharge pump for dehydration treatment. Each tank is equipped with an ultrasonic mud level gauge, and the sludge discharge pump controls the amount of sludge in the tank. The concentration of concentrated sludge is about 100 g / l.

The inclined tube separation area further removes the residual alum flowers in the water. The clarified water is collected by the water collection tank and enters the post-coagulation reaction area. After further reaction and pH adjustment, it is sent to the V-shaped filter. After the addition, the role of the coagulant is mainly to enhance the filtration effect of the filter and prolong the filtration cycle. In order to ensure the removal of the remaining oil slick, a manual oil skimmer is set up in the pre-sinking separation area. The skimmed oil slick is discharged through the pipeline to the oil sump in the sludge pump room, and is regularly transported out by the oil slick pump.

A DN600 external drainage pipe is installed behind the post-coagulation reaction zone. When the demand for recycled water is less than the water supply, part of the water reaches the standard and is discharged.

Main supporting equipment

    Mixing area mixer

    Flocculation area mixer

    Inclined pipe and supporting water collecting trough in the inclined pipe separation area

    Concentrated mud scraper with adjustable speed motor

    Screw pump for sludge circulation

    Screw pump for sludge discharge

Working characteristics

(1) Use synthetic organic flocculant PAM. Adding PAM as coagulant during coagulation makes the reaction produce larger alum, and the sludge reflux can further increase the density and settling performance of the alum, and accelerate its precipitation speed.

(2) The alum flower can be kept intact from the slow pushing flow reaction zone to the inclined plate precipitation zone, and the alum flower particles generated are large and dense.

(3) High-efficiency inclined plate precipitation can ensure a high ascending flow rate in the sedimentation area (up to 2O ～ 40 m / h), and flocculent alum can get a good precipitation.

(4) The sludge concentration can be effectively completed, and the concentration of sludge in the sedimentation tank can reach 15%, without the need for re-concentration, and can be directly dehydrated.

(5) High processing efficiency. Some literature shows that the removal rate of SS in high-efficiency sedimentation tanks is about 85%, the removal rate of COD can reach 85% -96%, and the removal rate of BOD is as high as 92%.

(6) The water treatment structure integrating coagulation, sedimentation and concentration functions has a compact structure, which reduces the cost of soil construction and saves construction land.

(7) The operating cost is relatively high, so it is necessary to optimize the control of the dosage of the medicament, so as to minimize the complete operating cost.

Advantages

The high-efficiency sedimentation tank has the advantages of high treatment efficiency, large water production per unit area, strong adaptability, strong impact load, stable treatment effect, and small footprint. This patented clarification technology with external sludge return must have a broad application prospect in the field of water treatment.

Disadvantages: The treatment process has many mechanical equipments, large energy consumption, complicated operation and management, difficult construction, and generally high investment.

Quantitative parameters

1. Inflow and outflow

2. Sludge reflux ratio

3. Excess sludge discharge

4. Residence time (SRT, HRT)

5. Sludge concentration

6. Conventional pollutant detection (pH, COD, BOD, SS, ammonia nitrogen, nitrate nitrogen, total nitrogen, total phosphorus, SV%, MLSS, MLVSS, etc.)

Hot Tags: high efficient sedimentation tank, China, suppliers, manufacturers, factory, customized, price, OEM