What Are the Best Tips for Silt Control?

Structure for sludge concentration. Generally adopt the shape like vertical flow or radial flow. It can be divided into batch operation and continuous operation. The former is mainly used in small sewage treatment plants or sewage treatment plants of industrial enterprises, while the latter is used in large and medium sewage treatment plants. The continuous gravity concentration tank has the same form as the radial flow sedimentation tank, and it can be divided into three types: mud scraper and sludge stirring device, without mud scraper, and multi-layer thickening pond (with mud scraper).

Sludge thickening tanks generally adopt a shape like vertical flow or radial flow. It can be divided into batch operation and continuous operation. The former is mainly used in small sewage treatment plants or sewage treatment plants of industrial enterprises, while the latter is used in large and medium sewage treatment plants. The continuous gravity concentration tank has the same form as the radial flow sedimentation tank, and it can be divided into three types: mud scraper and sludge stirring device, without mud scraper, and multi-layer thickening pond (with mud scraper).

The control of the sludge concentration tank includes the control of the amount of sludge input and the control of the amount of discharged concentrated sludge. Generally, there is no sludge storage tank before the concentration tank. In this way, the sludge discharged from the sewage treatment system directly enters the concentration tank. Therefore, the control of the concentration tank mainly refers to the control of the discharge of concentrated sludge. The main control methods of concentrated sludge discharge are:

(1) Control the start and stop of the mud pump with a timer;

(2) Use a timer and a preset counter to control the discharge of a certain amount of concentrated sludge every day;

(3) Use a timer to control the startup of the sludge pump, and stop the pump when the sludge concentration is reduced to a certain concentration using a sludge concentration meter;

(4) Use a timer to control the start of the pump, and use a sludge concentration meter, flow meter, and preset counter to stop the pump every time a certain amount of solids are discharged (based on dry sludge mass).

Large sewage treatment plants often adopt control methods (1). For semi-continuous operation control, the control method (2) is generally adopted for small sewage treatment. The control method (3) and (4) of the sludge concentration detector and the required hardware equipment are not complicated, but they are not widely used at present ^[3]

The sludge concentrating tank is composed of a sludge inflow pipe, an exudate outflow pipe, a stirring device and a sludge pump. When the sewage treatment capacity is less than 100 m ³ / d, a sludge concentration tank is set up for sludge treatment. The sludge concentration methods include gravity concentration method, floating concentration method and mechanical concentration method. High-concentration purification tanks generally adopt gravity concentration method. After the exudate flows out, the sludge concentration is guaranteed to be high. Its maintenance inspection content is as follows:

Check sludge concentration tank

Inspection method:

A Take water samples from the outlets of the exudates from sludge concentration tanks and catchment tanks.

B. Selection of sampling timing: the period from the start of transfer of excess sludge to the inflow of exudate.

C Exudate status: high concentration at the beginning of flow, low concentration in the middle, and high concentration in the final stage.

When the concentration of exudate is high or there is scum and sludge flowing out, the following inspections should be carried out:

A Determine the sludge interface.

B Check whether the scum and sludge accumulation in the pond are agitated.

C. Check for excessive accumulation of scum.

D Check and adjust the movement of the remaining sludge to confirm whether the capacity of the sludge pump is too large.

E Check the properties of activated sludge in the biological reaction tank.

Determination of scum and sludge accumulation thickness in a sludge concentration tank

Use an MLSS meter to measure the sludge accumulation thickness.

When the interface of the concentrated sludge is high, the leaching solution will be mixed into the concentrated sludge. It is necessary to check the sedimentation of activated sludge in the biological reaction tank.

Sludge concentration tank transfers sludge

Ensure the capacity of the sludge storage tank, and if necessary, pump out the sludge.

A Check whether the inflow of remaining sludge in the sludge concentration tank is within the designed effective volume.

B According to different treatment methods, the amount of remaining sludge is different. The remaining sludge generation rate of the purification tank is the ratio of the total amount of suspended matter to the amount of BOD removed.

When the scum reaches a certain thickness, measure the water level at the sludge interface and the exudate.

Use sludge pump to transfer sludge to sludge storage tank.

After the sludge transfer is completed, rinse the lower part of the exudate outflow pipe with clean water.

When the mud truck has difficulty in pumping and discharging mud, it shows that the concentration of sludge is high, and the stirring device in the tank is started to stir ^[4] .