JP4510699B2 - Surplus sludge treatment equipment - Google Patents

Description

The present invention relates to a surplus sludge treatment apparatus, and more particularly to surplus sludge treatment apparatus which can prevent the chlorine generation amount is lowered treatment effect decreases.

  Conventionally, surplus sludge treatment apparatuses that use surplus sludge generated by biological sewage treatment means as a substrate in an electrolytic cell are known (see Patent Documents 1 and 2).

JP 2003-62592 A JP 2002-126782 A

As shown in FIG. 7, when the operation is continued with the conventional surplus sludge treatment apparatus, the amount of chlorine generated in the electrolytic cell gradually decreases. This is because the inorganic and organic fine particles in the sludge become scales and gradually adhere to the surface of the electrode in the electrolytic cell.
However, when the amount of generated chlorine decreases, there is a problem that the treatment effect decreases.
Accordingly, an object of the present invention is to provide an operation method of an excess sludge treatment apparatus and an excess sludge treatment apparatus capable of suppressing a decrease in chlorine generation amount and a reduction in treatment effect.

In a first aspect, the present invention is an operation method of an excess sludge treatment apparatus for converting excess sludge generated by biological sewage treatment means into a substrate in an electrolytic cell, the introduction of the excess sludge into the electrolytic cell and Stop energization, discharge the accumulated matter in the electrolytic cell, introduce cleaning water and air into the electrolytic cell, and then discharge once or more, and then remove the excess sludge to the electrolytic cell. Provided is a method of operating an excess sludge treatment apparatus characterized by restarting introduction and energization.
In the method for operating the surplus sludge treatment apparatus according to the first aspect, the introduction and energization of the surplus sludge are stopped during the operation, the staying in the electrolytic cell is discharged, and then the cleaning water and air are introduced. At this time, the electrode surface is cleaned by the stirring effect of the cleaning water stirred with air washing the electrode surface and the wave effect of hitting the electrode surface while the rising water surface rises with air. After this is performed once or more, the introduction of surplus sludge and energization are resumed and the operation is continued. Thereby, it is suppressed that the inorganic and organic fine particles in the sludge become scales and adhere to the electrode surface. As a result, it becomes possible to suppress the chlorine generation amount from decreasing and the processing effect from decreasing.
In addition, the dirty washing water can be purified by returning the washing water discharged from the electrolytic cell after washing to the biological sewage treatment means.

In a second aspect, the present invention provides an electrolytic tank for converting surplus sludge generated by biological sewage treatment means into a substrate, and introducing or stopping introduction of the excess sludge into the electrolytic tank. Surplus sludge transfer means, energizing means for energizing or stopping energization of the electrolytic cell, discharging means for discharging the accumulated matter in the electrolytic cell, and introducing cleaning water into the electrolytic cell Cleaning water supply means for stopping or stopping the introduction, air supply means for introducing or stopping the introduction of air into the electrolytic cell, and control means for controlling the means The control means controls the surplus sludge transfer means and the energization means to stop the introduction and energization of the excess sludge to the electrolyzer, and controls the discharge means to control the inside of the electrolyzer. The accumulated matter is discharged, and the washing water supply means and The performed air supply means and said discharge means is controlled to the introducing the washing water and the air into the electrolytic cell and then one or more times to be discharged, then, by controlling the excess sludge transport means and said energizing means The surplus sludge treatment apparatus is characterized by restarting introduction and energization of the surplus sludge to the electrolytic cell.
In the surplus sludge treatment apparatus according to the second aspect, the operation method of the surplus sludge treatment apparatus according to the first aspect can be suitably implemented.

In a third aspect, the present invention is an operation method of an excess sludge treatment apparatus for converting surplus sludge generated by biological sewage treatment means into a substrate in an electrolytic cell, wherein the surplus sludge is introduced into the electrolytic cell and Stop energization, discharge the accumulated matter in the electrolytic cell, introduce chemical solution and air into the electrolytic cell, and then discharge once or more, and then introduce the excess sludge into the electrolytic cell And the operating method of the excess sludge processing apparatus characterized by restarting electricity supply is provided.
In the method for operating the surplus sludge treatment apparatus according to the third aspect, the introduction and energization of the surplus sludge are stopped during the operation, the staying in the electrolytic cell is discharged, and then the chemical solution and the air are introduced. At this time, the electrode surface is cleaned by the stirring effect of the chemical liquid stirred with air washing the electrode surface and the wave effect of hitting the electrode surface while the liquid level rising with air rises. After this is performed once or more, the introduction of surplus sludge and energization are resumed and the operation is continued. Thereby, it is suppressed that the inorganic and organic fine particles in the sludge become scales and adhere to the electrode surface. As a result, it becomes possible to suppress the chlorine generation amount from decreasing and the processing effect from decreasing.
In addition, since a chemical | medical solution is used, a high cleaning effect is acquired.

In a fourth aspect, the present invention provides an electrolytic tank for converting surplus sludge generated by biological sewage treatment means into a substrate, and introducing or stopping introduction of the surplus sludge into the electrolytic tank. Surplus sludge transfer means, energization means for energizing or stopping energization of the electrolytic cell, discharge means for discharging accumulated matter in the electrolytic cell, and introducing a chemical into the electrolytic cell. A chemical solution supply means for stopping the introduction, an air supply means for introducing air into or stopping the introduction into the electrolytic cell, and a control means for controlling the respective means. The control means controls the surplus sludge transfer means and the energization means to stop the introduction and energization of the excess sludge to the electrolytic cell, and controls the discharge means to control the accumulated matter in the electrolytic cell. The chemical solution supply means and the air Performed to introduce the drug solution and the air is then discharged by controlling the supply means and the discharge means of the electrolytic bath at least once, then the electrolyte by controlling the excess sludge transport means and said energizing means The surplus sludge treatment apparatus is characterized by restarting the introduction and energization of the surplus sludge to the tank.
In the surplus sludge treatment apparatus according to the fourth aspect, the operation method of the surplus sludge treatment apparatus according to the third aspect can be suitably implemented.

According to Surplus sludge treatment apparatus of the present invention, a result of particulate inorganic or organic substances in the sludge from adhering to the electrode surface becomes scale is suppressed, chlorine generation amount of the electrolytic bath is reduced treatment effects Can be suppressed.

  Hereinafter, the present invention will be described in more detail with reference to the embodiments shown in the drawings. Note that the present invention is not limited thereby.

FIG. 1 is a configuration diagram illustrating an excess sludge treatment apparatus 100 according to the first embodiment.
This surplus sludge treatment apparatus 100 is generated in the electrolytic tank 1, the power supply unit 2 for applying or stopping the application of a DC voltage to the electrodes 1 a and 1 b of the electrolytic tank 1, and the biological sewage treatment apparatus X. Circulation tank 3 for mixing the excess sludge F and the electrolytic sludge G that has been converted into a substrate in the electrolytic tank 1, the circulation pump P 1 for circulating the sludge between the electrolytic tank 1 and the circulation tank 3, and the excess sludge An introduction pump P2 for introducing F1 into the circulation tank 3 or stopping the introduction, a salt water tank 4 for storing salt water, and a salt water pump P3 for supplying salt water from the salt water tank 4 to the circulation tank 3 A drain valve V1 for discharging the accumulated matter in the electrolytic cell 1, a cleaning water pump P4 for introducing or stopping the cleaning water into the electrolytic cell 1, and air in the electrolytic cell 1. Air pump P5 for introducing or stopping introduction, and electrolysis The mud G are equipped with return valve V2 for returning to a biological sewage treatment apparatus X, and a controller 5 for controlling the power supply unit 2.

  The biological sewage treatment apparatus X includes an aeration tank A for biologically treating sewage and a precipitation tank B for precipitating excess sludge F generated by biological treatment.

FIG. 2 is a flowchart showing a procedure of surplus sludge treatment executed by the control unit 5.
In step S1, the introduction pump P2 is driven to introduce surplus sludge F from the sedimentation tank B of the biological sewage treatment apparatus X into the circulation tank 3, and the circulation pump P1 is driven to cause the electrolytic tank 1 and the circulation tank 3 to The sludge is circulated between the electrodes, and a DC voltage is applied from the power source 2 between the electrodes 1a and 1b. Moreover, the return valve V2 is opened, and the electrolytic sludge G is returned from the circulation tank 3 to the aeration tank A of the biological sewage treatment apparatus X. This is continued. For example, when it is 3:00 am, the process proceeds to step S2.

In step S2, the introduction pump P2 is stopped to stop the introduction of the excess sludge F, the circulation pump P1 is stopped to stop the sludge circulation, and the application of the DC voltage from the power supply unit 2 is stopped. Moreover, the return valve V2 is closed and the return of the electrolytic sludge G is stopped.
In step S3, the drain valve V1 is opened, and the stay in the electrolytic cell 1 is returned to the aeration tank A of the biological sewage treatment apparatus X. When the electrolytic cell 1 becomes empty, the drain valve V1 is closed. Then, the process proceeds to step S4.
In step S4, the value of the iteration counter n is initialized to “1”.

In step S5, the washing water pump P4 is driven to supply the treated water obtained in the sedimentation tank B of the biological sewage treatment apparatus X to the electrolytic cell 1 as washing water. Note that tap water, ground water, rain water, or the like may be used as cleaning water.
In step S6, the air pump P5 is driven to supply air to the electrolytic cell 1.
In step S7, the supply of cleaning water and air is continued until the electrolytic cell 1 is full. When the electrolytic cell 1 is full, the process proceeds to step S8.

In step S8, the cleaning water pump P4 is stopped to stop the supply of cleaning water.
In step S9, the air pump P5 is stopped and the supply of air is stopped.
In step S10, the drain valve V1 is opened, and the stay in the electrolytic cell 1 is returned to the aeration tank A of the biological sewage treatment apparatus X. When the electrolytic cell 1 becomes empty, the drain valve V1 is closed. Then, the process proceeds to step S11.

In step S11, the value of the iteration counter n is incremented by “1”.
In step S12, if the value of the iteration counter n is equal to or smaller than a predetermined number N (for example, N = 3), the process returns to step S5, and if not, the process returns to step S1.

-Evaluation test-
FIG. 3 shows the result of treating the excess sludge F with a capacity of 30 L, a treatment amount of 20 L / min, a washing frequency of 1 L / min, a washing water amount of 15 L / min, and an air amount of 30 L / min.
The amount of chlorine generated after 100 days of operation was 80% at the start.
In addition, when not performing washing | cleaning, as shown in FIG. 7, the amount of chlorine generation | occurrence | production after a 100-day driving | operation reduced to 50% at the time of a start.

  According to the surplus sludge treatment apparatus 100 according to the first embodiment, the generation of chlorine in the electrolytic cell 1 as a result of suppressing the inorganic and organic fine particles in the sludge from becoming scales and adhering to the surfaces of the electrodes 1a and 1b. It becomes possible to suppress the amount from decreasing and the processing effect from decreasing. Further, by returning the cleaning water discharged from the electrolytic cell 1 after cleaning to the biological sewage treatment apparatus X, the dirty cleaning water can be purified.

FIG. 4 is a configuration diagram illustrating the excess sludge treatment apparatus 200 according to the second embodiment.
This surplus sludge treatment apparatus 200 is basically the same as the surplus sludge treatment apparatus 100 of the first embodiment, but the chemical liquid pump P7 for supplying the chemical liquid to the electrolytic cell 1 and the accumulated matter in the electrolytic cell 1 are discarded. it is configured by adding the waste valve V 3 to.
As the chemical solution, acids and alkalis such as hydrochloric acid solution and sodium hydroxide solution, oxalic acid solution as a reducing agent, sodium hypochlorite solution as an oxidizing agent, and the like are used. You may use a some chemical | medical solution in order.

FIG. 5 is a flowchart showing the procedure of excess sludge treatment according to the second embodiment.
Since steps other than step S5 ′ to step S10 ′ are the same as those in the first embodiment, only step S5 ′ to step S10 ′ will be described.

In step S5 ′, the cleaning water pump P4 is driven to supply cleaning water to the electrolytic cell 1, and the chemical solution pump P7 is driven to supply chemical solution to the electrolytic cell 1.
In step S6, the air pump P5 is driven to supply air to the electrolytic cell 1.
In step S7, the supply of cleaning water and air is continued until the electrolytic cell 1 is full. When the electrolytic cell 1 is full, the process proceeds to step S8.

In step S8 ′, the cleaning water pump P4 is stopped to stop the supply of the cleaning water, and the chemical liquid pump P7 is stopped to stop the supply of the chemical liquid.
In step S9, the air pump P5 is stopped and the supply of air is stopped.
In step S10 ′, the drain valve V1 is opened and the disposal valve V3 is opened, so that the accumulated matter in the electrolytic cell 1 is discarded. When the influence of the staying matter on the biological treatment is small, the staying matter may be sent to the aeration tank A without being discarded. When the electrolytic cell 1 is empty, close the drain valve V1, close the waste valve V3. Then, the process proceeds to step S11.

-Evaluation test-
FIG. 6 shows the result of treating surplus sludge F with a capacity of 30 L, a treatment amount of 20 L / min, a washing frequency of 1 L / min, a washing water amount of 15 L / min, and a chemical supply amount of 1 L / min. As the chemical solution, 17.5% hydrochloric acid was used.
The amount of chlorine generated after 100 days of operation was 90% at the start.

  According to the surplus sludge treatment apparatus 200 according to the second embodiment, the generation of chlorine in the electrolytic cell 1 as a result of suppressing the inorganic and organic fine particles in the sludge from becoming a scale and adhering to the surfaces of the electrodes 1a and 1b. It becomes possible to suppress the amount from decreasing and the processing effect from decreasing. Moreover, since not only cleaning water but also a chemical solution is used, a high cleaning effect can be obtained. Furthermore, since it is the structure which can dilute a high concentration chemical | medical solution with a washing water, the chemical | medical solution tank which is not illustrated can be reduced in size.

  Rather than supplying cleaning water together with the chemical solution to the electrolytic cell 1 as in Example 2 described above, only the chemical solution adjusted to a concentration suitable for cleaning is supplied to the electrolytic cell 1 to clean the electrolytic cell 1. Good.

Surplus sludge treatment apparatus of the present invention can be used water treatment of water areas, sewage treatment, industrial water treatment.

It is a block diagram which shows the excess sludge processing apparatus which concerns on Example 1. FIG. It is a flowchart which shows the procedure of the excess sludge process which concerns on Example 1. FIG. 3 is a chart showing changes in the amount of chlorine generated by the excess sludge treatment apparatus according to Example 1. It is a block diagram which shows the excess sludge processing apparatus which concerns on Example 2. FIG. It is a flowchart which shows the procedure of the excess sludge process which concerns on Example 2. FIG. It is a chart which shows the change of the amount of chlorine generation by the surplus sludge processing apparatus concerning Example 2. It is a graph which shows the change of the chlorine generation amount by the conventional excess sludge processing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrolysis tank 2 Power supply part 3 Circulation tank 4 Salt water tank 5 Control part 100,200 Excess sludge processing apparatus P1 Circulation pump P2 Introduction pump P3 Salt water pump P4 Washing water pump P5 Air pump P7 Chemical pump V1 Drain valve V2 Return valve V3 Waste valve X biological wastewater treatment equipment

Claims (2)

An electrolytic tank for converting surplus sludge generated in biological sewage treatment means into a substrate, surplus sludge transfer means for introducing or stopping introduction of the excess sludge, and the electrolytic tank Energizing means for energizing or stopping energization, discharging means for discharging accumulated matter in the electrolytic cell, and for introducing or stopping the introduction of washing water into the electrolytic cell A cleaning water supply means; an air supply means for introducing or stopping the introduction of air into the electrolytic cell; and a control means for controlling the respective means. The surplus sludge transfer means and the energization means are controlled to stop the introduction and energization of the excess sludge to the electrolyzer, the discharge means is controlled to discharge the accumulated matter in the electrolyzer, and the washing water supply Means and said air supply means and front The discharge means is controlled to introduce the wash water and air into the electrolytic cell and then to discharge once or more, and then the excess sludge transfer means and the energization means are controlled to control the discharge to the electrolytic cell. excess sludge processing apparatus characterized by resuming the introduction and energization of excess sludge. An electrolytic tank for converting surplus sludge generated by biological sewage treatment means into a substrate, surplus sludge transfer means for introducing or stopping introduction of the excess sludge, and the electrolytic tank energizing means for or to stop the energization or energizing, the a discharging means for discharging the retentate in the electrolytic cell, chemical for or to stop the introduction or introducing chemical into the electrolytic bath A supply means; an air supply means for introducing or stopping introduction of air into the electrolytic cell; and a control means for controlling the respective means, wherein the control means includes the excess sludge. transport means and by controlling the energizing means to stop the introduction and energization of the excess sludge to the electrolytic cell, by controlling the discharge means to discharge the retentate in said electrolytic cell, the said chemical liquid supply means An air supply means and the discharge means; To introduce the drug solution and the air is then discharged before Symbol the electrolytic cell Gyoshi performed one or more times, then the excess sludge to the electrolytic cell by controlling the excess sludge transport means and said energizing means Surplus sludge treatment equipment characterized by restarting introduction and energization.

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