The Application Of Wasterwater Treatment Of Sedimentation Tank

In the sand products line, wastewater treatment is an indispensable link, and tailwater treatment is even more important. A sedimentation tank is a device that uses precipitation to remove suspended solids in wastewater and purify water. According to the shape of the primary sedimentation tank and the characteristics of the water flow, the primary sedimentation tank is usually divided into four types: advection, vertical flow, amplitude flow, and inclined plate tube type.

1. Advection Sedimentation Tank

The advection sedimentation tank has a rectangular shape. Wastewater flows in from one end of the tank, flows through the tank horizontally, and flows out from the other end of the tank. A mud bucket is set at the bottom of the entrance of the pool, and the bottom of the pool at other parts has a slope, inclined to the mud bucket.

Advantages

1) Good precipitation effect.
2) Strong adaptability to shock load and temperature changes.
3) Convenient construction.
4) Multiple pools are easy to integrate into one, saving floor space.

Disadvantages

1) The water distribution in the pool is not easy to be uniform.
2) When multiple buckets are used for sludge discharge, each bucket needs to be equipped with a separate sludge discharge pipe, which discharges sludge separately, and the operation volume is large.
3) When the mud scraper is used to discharge the mud, the supporting parts and driving parts are immersed in water, which is easy to rust.

Applicable Conditions

1) Suitable for areas with high groundwater levels and poor geology.
2) Suitable for large, medium, and small sewage treatment plants.

2. Vertical Flow Sedimentation Tank

The pool type is mostly round, and some are square or polygonal. Wastewater enters from the central pipe located in the center of the pond, and from the lower end of the central pipe through the reflector, it is evenly and slowly distributed on the cross-section of the pond. It is set on the pool surface or around the pool wall, so the flow of water is basically from bottom to top. The sludge is stored in the bottom sludge bucket.

Advantages

1) No mechanical mud scraping equipment, convenient mud discharge, and simple management.
2) Small footprint.

Disadvantages

1) The depth of the pool is large and construction is difficult.
2) Poor adaptability to shock loads and temperature changes.
3) Higher cost.
4) The pool diameter should not be too large, otherwise, the water distribution is uneven.

Applicable conditions

It is suitable for small sewage treatment plants with a small amount of water (the volume of a single tank is generally less than 1000m3).

3. Radial Flow Sedimentation Tank

The radial flow sedimentation tank is a large-scale sedimentation tank, the pool type is mostly circular, and the small tank is sometimes square or polygonal. The layout of the inlet and outlet of the tank is the same as that of the vertical flow tank, the inlet is in the center and the outlet is around. However, the ratio of the pool diameter to the pool depth is that the radial flow pool is many times larger than the vertical flow pool. The mud bucket is set in the center of the pool, and the bottom of the pool is inclined to the center. The sludge is usually removed by scraping (or suction) machinery.

Advantages

1) Most of the sludge is discharged mechanically, with the better operation and convenient management.
2) Mechanical (scraping) mud discharge equipment has tended to be finalized.
3) Good structural stress conditions.

Disadvantages

1) Large area.
2) The mechanical mud removal equipment is complicated, and the construction quality is high.

Applicable Conditions

1) Suitable for areas with high groundwater level and poor engineering geological conditions;
2) Suitable for large, medium, and small sewage treatment plants.

4. Inclined Plate Tubular Sedimentation Tank

The flow sedimentation tank is constructed by adding inclined plates or inclined pipes in the sedimentation zone of the sedimentation tank according to the shallow pool theory. It is composed of a sloping plate (pipe) sedimentation area, an inlet water distribution area, a clear water outlet area, a buffer zone, and a sludge area.

Advantages

1) High precipitation efficiency and short residence time.
2) The hydraulic load is high, more than double that of other sedimentation tanks.
3) Small footprint, saving civil construction investment.

Disadvantages

1) Under certain conditions, the inclined plate tube equipment has problems such as algae growth, which is inconvenient for maintenance and management.
2) It is difficult to discharge mud.
3) Inclined plates and inclined pipes are easy to block.