KR20200080563A - Automatic chemical dosing system for improving efficiency of sludge dehydration - Google Patents

Abstract

The present invention provides an automatic chemical feeding system using the surface charge density of sludge to automatically analyze a phase change and a moisture content to automatically control a feeding amount of a coagulant in real time. According to the present invention, the automatic chemical feeding system comprises: a charge measurement unit measuring the surface charge density of sludge; a flow rate control system constantly maintaining and supplying the inflow amount of sludge to the charge measurement unit; a control unit calculating a chemical feeding amount in accordance with a measurement value of the charge measurement unit and controlling overall operation; a feeding amount adjustment unit adjusting the chemical feeding amount in accordance with control of the control unit; and a monitoring unit collecting the surface charge density measurement value and the chemical feeding amount for the sludge from the control unit in real time to store and display the same.

Description

Automatic chemical dosing system for improving efficiency of sludge dehydration

The present invention relates to a chemical injection system for improving the dehydration efficiency of sewage and wastewater sludge, and more specifically, to automatically adjust the optimal flocculant injection amount to lower the water content of the sludge by analyzing the property change in real time using the surface charge density of the sludge. And an automatic injection system for chemicals for dewatering sewage and wastewater sludge that can be controlled.

Today, organic sludge, which is mainly generated and discharged from sewage treatment plants, wastewater treatment plants, and food waste treatment plants, is treated with a dehydrated cake after precipitation, concentration, stabilization, improvement, dehydration, etc., and then dried to power the thermal power plant. It is used as a supplementary fuel, etc.

In particular, in the dehydration process, the water content is lowered by injecting an appropriate amount of flocculant to reduce the volume of the sludge to facilitate handling and transportation.

As a method for determining the type and amount of flocculant during dewatering of the sludge, conventionally, a kind of model flocculation experiment, jar-test, was injected manually.

However, since this method cannot actively cope with changes in the properties of sludge that changes from time to time, it is only a laboratory-scale measurement method that does not take into account the conditions in the field due to excessive coagulant input and low water content reduction rate. Since the conditions for the proper injection amount with the flocculant show different results, the on-site worker is empirically operating with a different flocculant injection amount.

That is, Jatest is filled with an appropriate amount of samples in several beakers, and a flocculant is added thereto at different concentrations to precipitate by coagulation reaction for a certain period of time. As a calculation method, this takes about an hour or more to perform once, and thus there is a limit in determining a continuous injection amount.

In addition, since the mixing conditions in the treatment plant and the laboratory are significantly different, the accuracy is poor, so the amount of the flocculant determined through the Jatest is error-prone, thereby increasing the treatment cost when the flocculant is excessively injected and dehydrating. When under-injected, there is a problem that the processing efficiency is lowered.

Moreover, in the case of sewage sludge, it is difficult to optimally determine the amount of flocculant injection because it is composed of a complex system in which the types of microorganisms are diverse and the variation in the inflow concentration is not constant.

Therefore, in order to increase the dewatering efficiency of the sludge and reduce the treatment cost, there is a need to develop an automatic drug injection system that can automatically adjust the injection amount of the flocculant in accordance with changes in conditions and properties such as turbidity.

The above-described background technology or prior art is only to help the inventors understand the technical significance of the present invention as information possessed or acquired in the process of deriving the present invention, and the technology to which the present invention belongs prior to the filing of the present invention It is revealed that it does not mean a technique well-known in the field, and the reference numerals in the prior art are mutually independent of the reference numerals in the present invention.

KR10-1144580 B1(2012.05.02) KR10-1253481 B1(2013.04.05) KR10-0718036 B1(2007.05.08) KR10-0964895 B1(2010.06.11) KR10-2006-0100515 A(2006.09.21) KR10-2000-0033348 A(2000.06.15) KR10-1226945 B1(2013.01.22) KR10-1645540 B1(2016.07.29)

Accordingly, the present inventor has taken into consideration the technical limitations and problems of the method in which the operator periodically controls the amount of drug injection periodically through the existing jar-test while comprehensively considering the aforementioned matters, and sewage. By continuously measuring and analyzing the surface charge density (or surface charge) of the concentrated sludge generated in the treatment plant and receiving the size value, it automatically adjusts and controls the amount of flocculant injection that lowers the water content in real time, thereby increasing the dewatering efficiency of the concentrated sludge and using the flocculant. The present invention was invented as a result of continuous research with the utmost effort to develop a new automatic injection system for sludge dewatering with a new structure that can achieve the effect of reducing the amount.

Therefore, the technical problem and object to be solved by the present invention is to provide an automatic injection system for sludge dewatering, which enables automatic adjustment and control of the amount of flocculant injection in real time.

Here, the technical problems and objects to be solved by the present invention are not limited to the technical problems and objectives mentioned above, and other technical problems and objectives not mentioned will be clearly understood by those skilled in the art from the following description.

A specific means according to an aspect of the present invention for achieving the above object and solving the technical problem is a charge measuring unit for measuring the surface charge density of the sludge, the charge measuring unit constant in the amount of sludge flow A flow control system that maintains and supplies, a control unit that calculates a chemical injection amount according to the measured value of the charge measurement unit and controls the overall operation, an injection amount control unit that controls the chemical injection amount under the control of the control unit, and the surface charge of the sludge from the control unit We present an automatic injection system for sludge dewatering, characterized by employing a monitoring unit that collects and measures the density measurement value and the amount of chemical injection in real time and displays it in a database.

As a result, the present invention can optimize the injection amount of the drug (coagulant) by responding quickly to changes in the properties of the sludge, thereby obtaining the effect of reducing the drug cost as well as utilizing data according to real-time analysis. Efficiency can be improved.

A preferred embodiment of the present invention (aspect) further comprises a coagulation reaction tank for storing sludge, the injection amount control unit, a chemical tank for storing the drug, a quantitative injection pump for supplying a certain amount of the drug in the chemical tank to the coagulation reaction tank and the It consists of a PID control unit that controls the quantitative injection pump by comparing the amount of medicine injected from the medicine tank and the amount of medicine injected from the system control unit, thereby more effectively reducing the water content of the sludge and reducing the amount of coagulant used. have.

The aspect of the present invention with means and configurations for achieving the above object and solving the technical problem is a chemical (coagulant) irrespective of the load fluctuation by responding quickly and actively according to the real-time property change of the sludge. By optimally calculating and adjusting the injection amount and accurately injecting it, it is possible to maximize the dewatering efficiency of the sludge and prevent excessive injection of coagulant to reduce the amount of use.

In addition, it is possible to improve the efficiency and stability of the operation by real-time analysis of the surface charge density of the sludge and utilizing and reflecting the data according to the results of the flocculant injection treatment, and real-time monitoring of the flocculant injection rate change to promptly respond to errors. have.

In addition, it is possible to reduce the water content by injecting an appropriate amount by processing waste concrete, an industrial by-product, and slag powder to an appropriate particle size.

Here, the effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 is a schematic view showing a chemical injection system for sludge dehydration according to an embodiment of the present invention.
2 is a graph showing the results of PSA analysis of industrial by-products, which are physical improvers.
3 to 5 is a process for adjusting the charge of the sewage and wastewater sludge through an automatic drug injection system for improving the dehydration efficiency of sewage and wastewater sludge according to an embodiment of the present invention as a streaming current detector (SCD) It is a graph showing the measured result.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

Prior to this, terms to be described later are defined in consideration of the functions in the present invention, which clearly indicates that they should be interpreted in terms of concepts consistent with the technical spirit of the present invention and commonly recognized or commonly recognized in the art.

In addition, if it is determined that a detailed description of known functions or configurations related to the present invention may obscure the subject matter of the present invention, the detailed description will be omitted.

Here, the accompanying drawings are exaggerated or simplified for a convenience and clarity of description and understanding of the structure and operation of the technology, and it is revealed that each component does not exactly match the actual size and shape.

On the other hand, the automatic injection system for sewage and wastewater sludge dehydration according to an embodiment of the present invention is difficult to select the optimal coagulant injection amount because it consists of a complex system in which the types of microorganisms are various and the variation in the inflow concentration is not constant. It was proposed to improve the problem. Accordingly, the sludge in the coagulation reactor can be sampled and the data calculated therefrom can be fed back to control the drug injection rate and control the operation of the coagulation reactor.

Here, the sludge in the coagulation reactor may be concentrated sludge generated in a sewage treatment plant, and the water content of the concentrated sludge represents an average of 96.9%, the average temperature of 24.8°C, and the average pH of 7.3.

In addition, as a drug for reducing the water content of the concentrated sludge, it is possible to prevent the total phosphorus pollutant load from increasing by mixing a cationic polymer coagulant and iron salt (FeCl ₃ ).

Referring to Figure 1, the sludge dehydration chemical automatic injection system according to an embodiment of the present invention is largely a charge measuring unit 10, a flow control system 20, the control unit 30, the injection amount control unit 40, the monitoring unit ( 50), a coagulation reaction tank 60, a dehydration tank 70 and a physical modifier tank 80.

The charge measuring unit 10 is a device unit that receives a certain amount of sludge in the coagulation reaction tank 60 through the flow control system 20 and measures the surface charge density in real time and transmits the measured value to the control unit 30.

The charge measuring unit 10 may be a device for measuring a coagulant control condition through charge titration.

Here, the charge measuring unit 10 may be a device for measuring the flow potential while introducing and automatically stirring a coagulant having a cationic property to a certain amount of a sludge sample having a negative flow potential.

In this case, a flow ammeter can be used to measure the flow potential, and a sludge sample measuring the flow potential can be sent into the coagulation reactor 60.

That is, the flow rate control system 20 receives a quantitatively supplied sample of about 15 ml of sludge from the coagulation reaction tank 60 to measure the flow potential (mV), and measures the injection amount of the chemical (coagulant) when the flow potential becomes 0 mV. Then, it obtains data on the amount of cation required and transmits it to the control unit 30 for calculating the amount of drug (coagulant) injection.

For example, the charge measuring unit 10 measures the flow potential every time 5 ml of coagulant is supplied for 5 seconds at a time to calculate the amount of coagulant supplied when the flow potential is 0 mV, that is, the amount of cation required, and the calculated cation The requested amount data is converted into a digital signal and transmitted to the control unit 30.

Another example of the charge measurement unit 10 may include a plurality of electrodes, a voltage generator, and a current measurement device to measure the amount of charge. This means that the measurement voltage generated by the voltage generator is applied to the sludge through a plurality of electrodes inserted in the sludge, and the current measuring device measures the current flowing between the two electrodes inserted in the sludge.

That is, when the water content in the sludge is high, the measured current intensity increases, and when the water content is low, the measured current intensity decreases, so that the moisture content in the sludge can be measured by measuring the amount of charge.

The flow control system 20 is a device unit that supplies the sludge in the coagulation reaction tank 60 to the charge measuring unit 10 by keeping the inflow amount of the sludge constant.

That is, the flow rate control system 20 collects a predetermined amount of sludge samples in the coagulation reaction tank 60 at predetermined time intervals and transfers them to the charge measurement unit 10.

For example, the flow control system 20 may supply the sludge in the coagulation reaction tank 60 in units of 15 minutes to actively cope with changes in the properties and water content of the sludge.

Here, in order to stably control the flow rate of the sludge, the flow control system 20 may adopt an electric operation type that opens and closes the valve shaft by changing the signal amount of the control unit 30 to rotation of the electric motor.

The control unit 30 receives the measured value of the surface charge density of the charge measurement unit 10 and calculates and calculates the amount of coagulant injection according to the data value, and controls the overall operation of the system and the device.

In addition, the control unit 30 is electrically connected to the flow control system 20 and the injection amount control unit 40 to control their operation, and the amount of the flocculant injected (reference value) corresponding to the surface charge density measurement value of the charge measurement unit 10 ) Is extracted from the memory, and then a cohesive agent injection amount is calculated with an optimal value through a comparison operation, and the cohesive agent injection amount is adjusted by transmitting the calculated coagulant injection amount to the injection amount control unit 40 in the form of digital data.

At this time, the ratio of the amount of sludge sample supplied to the charge measurement unit 10 and the amount of sludge in the flocculation reactor 60 for injecting the flocculant is multiplied, and the calculated value is multiplied by the injection rate to obtain the total amount of the injected chemical (coagulant). The injection amount of can be calculated and determined, and data can be converted into a digital signal by an A/D converter and transmitted.

In addition, the control unit 30 has a built-in memory for storing programs and various data necessary for control operations and calculations.

That is, the control unit 30 arithmetically calculates the reference value of the injection amount of the flocculant injected into the coagulation reaction tank 60 according to the measured value of the surface charge density of the charge measurement unit 10 and the operation speed of the injection amount control unit 40. A database (memory) for storing in the form of a look-up table reflecting experimentally determined characteristic parameter values is provided.

Here, by storing the surface charge density compensation data according to the pH measured for each type of flocculant in the database (memory), the control unit 30 can extract the surface charge density compensation data from the database and control to compensate for the surface charge density of the flocculant. have.

The injection amount control unit 40 is a device unit that controls the injection amount of the chemical injected into the sludge of the coagulation reaction tank 60 under the control of the control unit 30.

Here, the injection amount control unit 40 includes a chemical tank 41 that stores a certain amount of a chemical such as a coagulant, and a quantitative injection pump 42 and a control unit for sending a predetermined amount of the chemicals in the chemical tank 41 to the coagulation reaction tank 60. 30) PID control unit that controls the quantitative injection pump (42) by PID control (Proportional Integral Derivative Control) method compared to the amount of medicine injected from the medicine tank (41) to the coagulation reaction tank (60) after receiving the calculated medicine injection amount (43).

That is, the chemical tank 41 is connected to a coagulation reaction tank 60 and piping to supply a coagulant, and the quantitative injection pump 42 is a bellows pump or diaphragm in which the chemical is discharged quantitatively. It consists of a pump and is installed on the pipe connecting the chemical tank 41 and the coagulation reaction tank 60.

In addition, the PID control unit 43 quantitatively injects the amount of the chemical (coagulant) injected from the actual medicine tank 41 into the coagulation reaction tank 60 as the target injection amount received from the control unit 30 through PID control. The injection amount of the chemical (coagulant) is adjusted by controlling the rotational speed or stroke of the pump 42 or opening and closing the valve by a set standard value.

For example, the injection amount control unit 40 is a surface charge density measurement value of the charge measurement unit 10, that is, if the charge amount of the sludge is -100mA or less, the valve of the metering injection pump 42 is controlled to open, and more than +100mA If it is, it can be controlled to close the valve of the metering pump 42.

Through the PID control unit 43, it is possible to minimize the error and deviation between the actual coagulant injection amount and the calculated coagulant injection amount, and to provide feedback control reflecting the results after coagulant injection to actively reach the coagulant injection amount calculated in a short time.

Here, since the concentrated sludge has a strong negative charge on the particles, the coagulant may be a polyacrylamide-based medium cationic polymer coagulant.

That is, since the surface charge density or the streaming potential of the sludge has a negative value, it may be desirable to use a cationic organic polymer coagulant for charge titration. As a cationic coagulant, poly-dadmac, Alum, Raifix, Polyamine, PAC (Poly Aluminium Chloride), PACS (Poly Aluminium Silicate Chloride), etc., which act to deodorize water in the sludge through coagulation reaction with sludge, can be selectively used. have.

The monitoring unit 50 is connected to the control unit 30 by wire or wireless, collects the surface charge density measurement data and chemical injection amount data of the sludge in real time, and makes a database and displays the correlation.

Here, the monitoring unit 50 may include an interface for searching history information and a display for displaying various information such as history information and operation status.

That is, the monitoring unit 50 displays the surface charge density of the sludge and the amount of chemical injection through a display, so that the field worker can monitor the change in properties of the sludge in real time.

The coagulation reaction tank 60 contains a predetermined amount of sludge to be dehydrated, and a solid/liquid separation reaction occurs by the coagulant injected from the injection amount control unit 40.

Here, the coagulation reaction tank 60 may be formed of a device for stirring the flocculant and sludge under the control of the control unit 30.

That is, the control unit 30 may control the agitation operation of the coagulation reaction tank 60 while controlling the injection amount control unit 40. At this time, the agitation strength of the coagulation reaction tank 60 can be appropriately controlled according to the inflow amount of the sludge and the injection amount of the coagulant.

Automated injection system for chemicals for dewatering sludge according to an embodiment of the present invention includes a dewatering tank 70 for dewatering sludge supplied from a coagulation reaction tank 60, and a physical improver tank 80 for supplying a physical improver to the dewatering tank. can do.

In order to improve the dewatering efficiency of the sludge, it is necessary to improve not only the efficiency of chemical improvement of the sludge by administration of a coagulant, but also improvement in the mechanical dewatering process. As a method of improving the efficiency in the mechanical dehydration process, a method of replacing or supplementing the dewatering device with a more efficient device is typical. In the present invention, in order to improve the mechanical dewatering efficiency of the sludge, a physical improver of construction waste or a by-product of steelworks is supplied to the dewatering tank 80. At this time, the physical improver may be supplied to the coagulation reaction tank 60, not the dehydration tank 80.

In order to reduce the water content of the sludge, a predetermined quantity is injected through the quantitative injection pump 61 to reduce the water content of the sludge. At this time, the physical improver is used by processing industrial by-products of waste concrete and slag powder and adjusting it to an appropriate particle size.

As a result of these construction wastes or by-products of steelworks, CaO, SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , K ₂ O, etc. are composed of major components, and when used as an additive to improve sludge, PSA for particle size analysis is performed. (See FIG. 2) The average particle size (D ₅₀ ) of the industrial by-product powder was 16 μm, and D ₉₀ was 52 μm. XRF analysis results are shown in Table 1 below.

division ingredient Content (wt%) One CaO 36.76 2 SiO ₂ 34.16 3 Al ₂ O ₃ 10.09 4 Fe ₂ O ₃ 9.57 5 K ₂ O 4.06 6 SO ₃ 1.39 7 TiO ₂ 1.14 8 MgO 0.92 9 SnO ₂ 0.49 10 P ₂ O ₅ 0.38 11 MnO 0.24 12 BaO 0.16 13 Na ₂ O 0.12 14 SrO 0.11 15 ZnO 0.08 16 Cl 0.07 17 ZrO ₂ 0.04 18 Rb ₂ O 0.03 19 PbO 0.03 20 Cr ₂ O ₃ 0.03 21 CuO 0.01 22 NiO 0.01 23 Nb ₂ O ₅ 0.01

It can improve the mechanical strength and permeability of the solid. In addition, it is possible to improve the dewaterability by reducing the compressibility of the secondary sludge and transform the floc into a more robust structure.

The main operation and operating principle of the automatic injection system for sludge dewatering according to the embodiment of the present invention configured as described above are as follows.

First, the flow rate control system 20 collects a certain amount of sludge sample from the coagulation reaction tank 60 and supplies it to the charge measurement unit 10 for a predetermined time.

Subsequently, the charge measuring unit 10 measures the surface charge density of the sludge, converts the measured data into a digital signal, and transmits it to the control unit 30.

Subsequently, the control unit 30 analyzes the surface charge density measurement value transmitted from the charge measurement unit 10, calculates and determines the injection amount of the drug (coagulant) based on the comparison with the preset reference value and related data, and then calculates the calculated data Is converted to a digital signal and transmitted to the injection amount control unit 40.

At this time, when the average charge value of the sludge is a negative value, the control unit 30 transmits a control signal for increasing the injection amount of the flocculant to the injection amount control unit 40, and when the average charge value is a positive value, the injection amount control unit 40 ) To transmit a control signal to reduce the amount of coagulant injection.

Subsequently, the injection amount control unit 40 controls the quantitative injection pump 42 according to the control signal from the control unit 30 to control the amount of the drug (coagulant) in the chemical tank 41 to be injected into the coagulation reaction tank by a predetermined amount. .

That is, when the water content in the sludge is high, the amount of flocculant supplied to the coagulation reaction tank 60 is increased by increasing the amount of opening of the metering pump 42, and in the opposite case, the amount of flocculation pump 42 is reduced to agglomerate. Reduce the amount of coagulant supplied to the reactor 60.

At this time, the PID control unit 43 controls the opening and closing speed and time of the quantitative injection pump 42 by comparing the amount of the medicine injected from the medicine tank 41 to the coagulation reaction tank 60 and the amount of the medicine injected from the control unit 30. do.

Thus, since a certain amount of drug is injected into the first agglomeration reaction tank 60 in the chemical tank 41, the control unit 30 compares the surface charge density transmitted from the charge measurement unit 10 with the measured value and the reference value to produce the drug (coagulant. ) When calculating and determining the injection amount, if the two values match, the existing injection amount of the drug is maintained, and if the two values are different, the injection amount is determined to correspond to the difference between the two values.

For example, if the reference value is 100 and the measured surface charge density value is -500, the metering pump 42 is controlled to inject the chemical (coagulant) into the coagulation reaction tank 60 until the surface charge density value becomes 100. do.

At this time, the comparison of the reference value and the surface charge density measurement value is performed by the control unit 30, and the determination of the injection amount of the chemical (coagulant) is performed by the injection amount control unit 40. Can be implemented through

In this process, the monitoring unit 50 receives the measured value of the surface charge density of the sludge and the signal value of the chemical injection amount from the control unit 30 in real time, converts and collects it, stores it in a database, stores it, and displays it on the display, so that workers Coagulant) It is possible to monitor the injection process in real time and immediately respond to errors.

As described above, the automatic injection system for sludge dewatering chemicals according to an embodiment of the present invention measures real-time properties and water content changes of sludge flowing into the flocculation reactor 60, and uses the data to optimally calculate and adjust the amount of flocculant injection. .

Therefore, it is possible to increase the dewatering efficiency of the sludge and prevent excessive injection of the flocculant, thereby reducing the amount of use.

In addition, it is possible to improve the efficiency of operation by analyzing the amount of flocculant injection in real time and utilizing and reflecting data according to the result of the processing.

On the other hand, the present invention is not limited by the above-described embodiments and the accompanying drawings, and can be variously modified and applied in various ways that are not exemplified without departing from the scope of the technical spirit of the present invention. It is apparent to those of ordinary skill in the art to which the present invention pertains that the invention may be broadly applied by changing the substitution and other equivalent embodiments.

Therefore, contents related to modifying and applying the technical features of the present invention should be interpreted as being included within the technical spirit and scope of the present invention.

Hereinafter, preferred embodiments of the present invention will be described. However, the following examples are only preferred examples of the present invention, and the present invention is not limited to the following examples.

Example 1: Measurement of sludge dehydration according to the amount of cation flocculant injection

1. Capillary suction time (CST) measurement

It is often used as a fast and reliable method. The capillary suction pressure generated by the standard filter paper is used to intake moisture from the sludge, and the ratio of the moisture permeating through the filter paper varies depending on the condition of the sludge and the filtering ability of the cake formed on the filter paper. The CST is calculated between two electrodes mounted at standard intervals from the funnel, and is calculated as the time taken for the water front passing between the two electrodes.

2. Time to filter (TTF)

Time to Filter (TTF) is a measure of the time it takes for 50% of the sludge volume to escape into the filtrate, and is often used together with CST to evaluate the sludge dewaterability of the lab scale. The filtration time is related to the capillary suction time, and is similar to the specific resistance to filtration unless the sludge solids content and the viscosity of the filtrate change between comparative samples.

When the cation flocculant was injected through the automatic drug injection system of the present invention, the dewaterability of the sludge according to the injection amount was confirmed by measuring CST and TTF, and the results are shown in Table 2 below.

Solid cation flocculant injection amount CST
(sec) CST average TTF
(min,sec) TTF average 0 7.1 7.53 20 seconds 22.67 seconds 7.7 24 seconds 7.8 24 seconds 5 6.1 6.23 12 seconds 11.67 seconds 6.6 11 seconds 6.0 12 seconds 10 6.7 6.43 9 seconds 9.67 seconds 6.3 11 seconds 6.3 9 seconds 30 8.5 8.53 1 minute 22 seconds 1 minute, 43 seconds 8.3 2 minutes 8.8 1 minute 48 seconds 50 10.4 10.47 2 minutes 44 seconds 2 minutes 38 seconds 10.7 2 minutes 51 seconds 10.3 2 minutes 21 seconds

In general, if the CST is 10 seconds or less, the dehydration property is good, and the TTF is judged to be a good value if it is within 1 minute. As a result of this experiment, the amount of cation flocculant injection was found to be the best dehydration in the range of 5ml~10ml/L sludge, and this result was set as the initial value of the chemical injection system for dewatering sewage and wastewater sludge.

3 to 5 is a process for adjusting the charge of the sewage and wastewater sludge through an automatic drug injection system for improving the dewatering efficiency of sewage and wastewater sludge according to an embodiment of the present invention as a streaming current detector (SCD) It is a graph showing the measured result.

3 is a result of observing the surface charge value before reaching the sludge surface charge optimization, FIG. 4 is a result of optimizing the surface charge of the sludge according to the operating time, and FIG. 5 is a result of adjusting the surface charge of the sludge according to the operating time.

Example 2

The sludge used in this experiment is the return sludge from Seonghwan Sewage Treatment Plant in Cheonan, Chungcheongnam-do. The sludge treatment was carried out with the automatic injection system for dehydration of sewage and wastewater sludge of the present invention, and was used by processing waste concrete into an appropriate particle size. The TTF, CST, water content, and return water T-P of the treated sludge were measured, and the analysis method is as follows:

1. TTF (Time to Filter)

As a method of measuring the time taken to obtain filtrate of 50% of the original sample volume by vacuum filtration of the modified sludge sample, this test measures the time taken to filter 100 ml by filtering 200 ml.

2. CST (Capillary Suction Time)

CST puts the improved sludge in the cylinder above the filter paper, extracts the liquid from the sludge and wets the filter paper by capillary action. At that time, the time required for the filtrate to flow through 1 cm of the filter paper was measured and used as a result.

3. Water content

As a method of measuring the moisture of the sample, the sample was dried at 105 to 110° C. for 4 hours, cooled in a desiccator, and weighed to obtain the amount of moisture (%) from the weight difference.

4. Counterflow T-P

Oxidative decomposition of phosphorus in the form of organic compounds in the sample changes all phosphorus compounds to phosphate, and then absorbs ammonium molybdate produced by reacting with ammonium molybdate to ascorbic acid to absorb absorbance of molybdic acid, etc., generated at 880 nm. It is a measure.

The analysis results are shown in Tables 3 to 6 below.

division Sample 1 Sample 2 Sample 3 TTF(sec) 29 31 31 Average 30.3 (sec)

Sample 1 Sample 2 Sample 3 CST (seconds) 7.9 7.9 8.4 Average 8.1(sec)

division Water content (%) Sample 1 77.6 Sample 2 82.5 Sample 3 74.3 Sample 4 81.0 Sample 5 82.7 Sample 6 75.7 Sample 7 64.2 Sample 8 80.8 Sample 9 67.8 Sample 10 81.4 Average 76.8

division T-P (mg/L) Sample 1 0.446 Sample 2 1.688 Sample 3 1.686 Sample 4 1.658 Sample 5 1.674 Sample 6 1.662 Sample 7 1.684 Sample 8 1.680 Sample 9 1.672 Sample 10 1.672 Average 1.552

10: charge measuring unit 20: flow control system
30: control unit 40: injection amount control unit
41: chemical tank 42: metering pump
43: PID control unit 50: monitoring unit
60: coagulation reaction tank 70: dehydration tank
80: physical improver tank

Claims (6)

Charge measuring unit for measuring the surface charge density of the sludge;
A flow rate control system that maintains and supplies a constant amount of sludge inflow to the charge measurement unit;
A control unit for calculating the amount of drug injection and controlling the overall operation according to the measured value of the charge measurement unit; And
An injection amount adjusting unit for adjusting the injection amount of the medicine injected into the sludge under the control of the control unit;
Automatic injection system for chemicals to improve the dehydration efficiency of sewage and wastewater sludge containing. According to claim 1,
A coagulation reaction tank containing sludge;
Further comprising,
The injection amount control unit,
A chemical tank for storing chemicals;
A quantitative injection pump that delivers a certain amount of the medicine in the medicine tank to the coagulation reaction tank; And
A PID control unit that controls the quantitative injection pump by comparing the amount of medicine injected into the coagulation reaction tank and the amount of medicine injected from the control unit;
Automatic injection system of chemicals to improve the dehydration efficiency of sewage and wastewater sludge containing. The method according to claim 1 or 2,
A monitoring unit that collects, measures, and displays the surface charge density measurement data and chemical injection amount data of the sludge in real time from the control unit;
Automated chemical injection system for improving the dehydration efficiency of sewage and wastewater sludge further comprising a. According to claim 2,
The drug to be introduced into the coagulation reaction tank,
Automatic injection system of chemicals to improve the dehydration efficiency of sewage and wastewater sludge containing cationic polymer coagulant and iron salt (FeCl ₃ ). According to claim 1,
A dehydration tank for dewatering sludge supplied from the coagulation reaction tank;
Physical improver tank for supplying a physical improver to the dewatering tank
Automated chemical injection system for improving the dehydration efficiency of sewage and wastewater sludge further comprising a. The method of claim 5, wherein the physical modifier,
Automatic injection system of chemicals to improve the dewatering efficiency of sewage and wastewater sludge, which is a by-product of construction waste or steelworks.

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