JPS60190300A - Treatment of screen dregs - Google Patents

Abstract

PURPOSE:To dispense with an exclusive washing tank or an exclusive dehydrator and to rationally dehydrate sludge, by mixing separated screen dregs obtained by applying solid-liquid separation to a slurry with sludge generated by org. sewage treatment before applying dehydration treatment to the resulting mixture. CONSTITUTION:A slurry 14 obtained after the treatment of sewage 1 receives solid-liquid separation treatment in a solid-liquid separation process 17 and the liquid component 18 is sent to an aeration tank 9 and treated therein. Washed and separated screen dregs 19 are mixed with concn. sludge 20 concentrated by a thickener 7 and, thereafter, a dehydration additive such as a cationic polymer is added to the resulting mixture if necessary. Next, said mixture is dehydrated by sludge dehydration equipment 21 such as a roll or belt press dehydrator, a centrifugal dehydrator, a vacuum dehydrator or a screw press dehydrator to form a dehydrated cake 22. Furthermore, it is rational to mix separated screen dregs 19 only in excessive sludge 12 without together treating initial precipitated sludge 6 and excessive sludge 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for rationally treating screen residue generated during the treatment of other organic sewage from a water tank.

[Prior art]

Organic sewage generally contains a lot of impurities such as paper, hair, and vegetable scraps, so these impurities are first removed with a screen and then treated with activated 1'5 mud treatment. It is - [there is. The impurities removed by screens (hereinafter referred to as "screen scum") are extremely unsanitary and are conventionally disposed of by landfill or incineration, but during transportation of screen scum, a foul odor is generated and sewage is disposed of. This can lead to secondary pollution such as leakage of water, so in many cases dedicated processing facilities for screen waste are being set up, where the screen waste is washed in an agitating cleaning tank and then dehydrated.

However,7 such a method naturally requires a large amount of installation and maintenance costs, as well as maintenance and burial personnel, in order to install a screen scum cleaning tank and dewatering machine. There were drawbacks.

[Purpose of the invention]

The present invention aims to provide a method that eliminates the need for a dedicated cleaning tank and dehydrator, which were conventionally indispensable for treating screen scum, and at the same time rationally dewaters sludge generated during the organic sewage treatment process. This is the purpose.

[Structure of the invention]

In organic sewage treatment, the present invention involves removing impurities and impurities in the sewage with a screen, draining the resulting screen-grained water, and then pumping the suspended slurry with a pump. The method is characterized in that the resulting ii5 turbid slurry liquid is separated to obtain a separation screen sludge, the separation screen sludge is mixed with the sludge generated in the organic sewage treatment, and then dehydrated in a dewatering facility.

〔Example〕

To explain with reference to the drawings which are an embodiment of the present invention, sewage 1 (including sewage discharged in rainy weather) flows into a screen 2 and is separated into screen scum 6 and sewage 4.

The filtered sewage 4 is then subjected to sedimentation and separation in the first settling tank 5.
Separated initial settling sludge 6 is led to Shirafuna 7, while supernatant water 8 is biologically treated in an aeration tank 9 and then transferred to a final settling tank 1.
The water is further separated by sedimentation at 0, and the supernatant becomes treated water 11 and flows out. Further, a part of the sludge that has been settled and separated in the final settling tank 10 is returned to the aeration tank 9, and the remaining surplus sludge 12 is led to the Shirafuna 7 and concentrated together with the initial settling tll mud 6.

On the other hand, the screen dregs 6 separated by the screen 2 are
If necessary, the slurry is shredded by a shredding machine 16 and then mixed with a portion 4' of the sewage 4 or fresh water or other suitable water) to form a turbid slurry 14, which is then passed through a pipe 16 by a pump 15. The sludge dewatering equipment 21, which will be described later, is installed at or near the installation site, and the sludge is sent under pressure to a solid-liquid separation process 17, such as an extra screen, centrifugation, or gravity separation. This stake? 1.:5 slurry 14
Ino pressure feeding by the pump 15 of the present invention is described in 16 and II (
In addition to its transportation function, it also has the important function of cleaning the screen 6 with tLI in the pipe 16 during transportation. Motsu-C is here. In general, the installation of the screen 2"easy" and 7r5 mud) le; 1
Water installation 1iii 21 installation f'2 location is far away,
There is a distance of several tens to several gonl in the water treatment area, and it may reach a distance for rice, and the screen waste 6 is transferred to the pipe line during pressure feeding by the pump 15. It was confirmed that V-washing a) was carried out sufficiently in 16.

In this way, the %i turbid soot slurry pumped by C1 was mixed with 14° solid-liquid content &ji'C engineering 44i 17 at the same time, and
The liquid portion 18 is sent to the aeration tank 9 and subjected to 'C treatment. In addition, the washed and separated sludge 19 is mixed with the thickened sludge 20 concentrated in the Shirafuna 7, and if necessary, a dewatering aid such as a cationic polymer is added, and then a roll or Sludge dewatering equipment 2 such as Peltogeles IiQ/Niiso, centrifugal dehydrator, vacuum dehydrator, screw press dehydrator, etc.
The cake is dehydrated in step 1 to become a dehydrated cake 22.

In the processing method, the screen residue 6 is shredded by a shredder 16.
When it is shredded, the cleaning effect of the screen sludge 6 is significantly enhanced, and the mixing with the thickened sludge 20 becomes easier to homogenize, which has the combined effect of improving the dewatering effect.

In addition, as described above, it is also reasonable to treat the initial settling sludge 6 and the surplus sludge 12 together (and to mix the separation screen sludge 19 only with the surplus sludge 12. In other words, it is reasonable to Since the addition ratio of the separation screen sludge 19 to the bad surplus sludge 12 increases, it is possible to effectively remove the surplus N5 IQ 119 water, which is considered to be a water-releasable one, and to use a sludge that originally has good concentration and dewatering properties. This is extremely rational since the sludge 6 can be easily dehydrated separately.

Furthermore, by mixing the separated screen sludge 19 that has been washed and separated into the /l mud, the fiber content in the 1-separated screen sludge 19 acts as a dehydration aid for the sludge, resulting in a dehydrated cake with an extremely low water content. However, when a screw press dehydrator is used as the sludge dewatering equipment 21, the fiber content t prevents the sludge from t1ψ rotation and co-rotation, and when the pressure is sufficient, a dehydrated cake 22 with an extremely low water content can be obtained. You can do that if you get it.

Note that the solid-liquid separation step 17 of the i'1; At the same time, it is also possible to perform solid-liquid external 1IIF&, making it possible to effectively utilize existing facilities.

Also, the sedimentation abyss condition is extremely good +)! 1! The t45 sludge is compacted by the I# screen sludge 19, and the degree of compaction of the sludge itself can be improved.

[Effect of δ light]

As described above, according to the present invention, organic ρl water treatment 1
It is possible to treat both the screen waste and the sludge that go into the tank very rationally, and the following beneficial effects are produced.

(By mixing the rescreen scraps, the screen scraps and sludge can be treated at the same time, and the sludge can be dehydrated in a very integrated and effective manner, making it possible to obtain a dehydrated cake with an extremely low water content.

(Re) Conventional cleaning, dehydration, and storage of only screen scum,
This eliminates the need for various operations such as transportation, and prevents secondary pollution.

■ Installation of cleaning tank, dehydrator, etc. exclusively for screen residue (+i
FI becomes a barrier, and equipment costs, maintenance, and expenses can be reduced by 1j.

[Brief explanation of drawings]

The drawing is /l (system explanatory diagram showing one embodiment of the invention. 1...Sewage, 2...Screen, 6...Screen gas, 4, 4'...Sewage directly removed, 5 ... Initial settling tank, 6... Initial settling sludge, 7... Shirafuna, 9... Aeration tank, 10... Final settling tank, 11... Treated water, 12.
...Excess sludge, 16...A (B cutter, 14...Suspended slurry, 15 River pump, 16...Pipe line, 17...Solid-liquid separation; Associate process, 19... Separation screen residue, 20
...Thickened sludge, 21...79 Sludge dewatering equipment. 22...Dehydrated cake. Patent applicant: Ebara Infilco Co., Ltd. Representative Patent attorney: Masayuki Takagi

Claims (1)

[Claims] J. In organic wastewater treatment, impurities in the wastewater 4
- After suspending the screen residue obtained by removing it with a screen in water, the suspended slurry is pumped to a pump at °C, and this pumped suspended slurry is transferred to a solid liquid needle! ! +18 and get a separation screen scrap. A method for treating screen dregs, which comprises mixing the separated screen dregs with the sludge generated in the organic sewage treatment and then dewatering the sludge in a dewatering facility. 2. The method for treating screen scum according to claim 1, wherein the screen scum is shredded and then suspended in water. 3. The method for treating screen dregs according to claim 1 or 2, wherein the sludge generated in the organic water treatment is surplus sludge. 4. The method for treating screen dregs according to claim 1, 2 or 2, wherein the dewatering equipment uses a screw press dehydrator.