KR20080008050A - Device and methode for water purification - Google Patents

Abstract

An apparatus and a method for purifying water are provided to purify the water reliably and manage the apparatus easily, by improving the evaluation of a coagulating process and reflecting the evaluation in control of a coagulating power. An instant mixing unit(100) mixes coagulant and raw water instantly. A coagulant input and control unit(170) inputs the coagulant into the instant mixing unit and controls the input of the coagulant. A coagulating unit(200) receives mixture water from the instant mixing unit, and performs a coagulation process on the mixture water by a stirring unit. A coagulation measurement and control unit(250) measures the coagulation state and controls the coagulation process within the coagulating unit. The coagulation measurement and control unit includes a light scatter analysis unit(251) and a stir power control unit(252). The light scatter analysis unit measures the growth state of coagulating flocculation through light scatter analysis to evaluate a change tendency of a light scatter analysis value or a light scatter analysis ratio. The stir power control unit controls the stir power so that the light scatter analysis value or the light scatter ratio tends to rise. Further, an adjusting unit is additionally installed in order to adjust an instant mixing strength.

Description

Water treatment device and method {Device and methode for water purification}

Fig. 1 is a schematic diagram schematically showing the configuration of another water treatment apparatus in one embodiment of the present invention.

2A is a schematic diagram showing an instantaneous admixture according to an embodiment of the present invention.

FIG. 2B is a schematic diagram showing the flow in the injection pipe of FIG. 2A together with the deflector. FIG.

Figure 3a is a schematic diagram showing a coagulation drug injection control device according to an embodiment of the present invention.

3B is an enlarged schematic view of the structure of the flow current meter of FIG. 3A.

Figure 3c is a flow chart showing a logic configuration for performing coagulation drug injection control in the present invention.

4 is a graph showing the correlation between the flocculation chemical injection rate and the flow current value (SPD) (a) and the residual turbidity (b) of the precipitated water.

5 is a coagulant injection amount by the flow current value for the raw water of pH 7.5 or more, turbidity 10 NTU or more is not required to adjust the pH of the mixed water to evaluate the automatic control performance of the flocculation drug injection rate according to the raw water turbidity change This is a graph showing the result of continuous operation such that the automatic control is performed.

6 is a coagulant injection amount by the flow current value for raw water of pH 7.5 or less, turbidity of 40 NTU or less required to adjust the pH of the mixed water to evaluate the automatic control performance of the flocculation drug injection rate according to the turbidity and pH change of the rainy season raw water This graph shows the results of continuous operation for automatic control.

Figure 7a shows the amount of flocculation chemical injection by the flow current value for raw water of pH 7.5 or less, turbidity 35 NTU or less required to adjust the pH of the mixed water to evaluate the automatic control performance of the flocculation chemical injection rate according to the turbidity and pH change of rainfall This is a graph showing the result of continuous operation so as to control automatically.

7B and 7C are graphs showing the relationship between pH and turbidity of mixed water and the relationship between pH, turbidity, and flocculation chemical injection rates of mixed water when the self-test was performed on rainfall-high turbidity (25.9 to 31.9 NTU) raw water.

8A is a schematic view showing a vertical axis stirring device of the high efficiency flocculation device used in the present invention.

FIG. 8B is a schematic diagram showing the flow of treated water in the flocculation device using the stirring device of FIG. 8A.

9 is a view showing a light scattering analysis concept of the light scattering analysis device of the present invention.

FIG. 10 is a basic experiment result for examining changes in RMS and ratio for agglutination drug injection in the present invention. RMS measured as a result of the aggregation (30 rpm, 30 min) and precipitation (30 min) experiments of the Jar test. And graph showing ratio.

11 is a graph showing a ratio pattern in the case of monitoring or controlling the aggregation process using the light scattering analyzer in the present invention.

FIG. 12 is a graph showing turbidity and streaming potential (SP) change according to agglomerating drug injection during the magnetic test.

FIG. 13 is a graph showing change characteristics of RMS (a) and ratio (b) during agglomeration precipitation in the Jar test experiment used in FIG. 12.

FIG. 14 is a graph showing a coagulation pattern using a ratio when the stirring power is changed (E1, E2, E3, E4, E5) when controlling the amount of coagulation drug injection using SP in the instantaneous admixture according to the present invention.

15 is a coagulation pattern using the ratio when the stirring power is changed (E1, E2, E3, E4) when the mixture is instantaneously mixed with instantaneous injection of sodium hydroxide (NaOH 20%) and SP control in the present invention. A graph representing.

16 to 19 are graphs showing the results of grasping through the light scattering analyzer the flocs grown in each unit flocculation unit of the actual water treatment plant to which the instantaneous admixture, automatic flocculation chemical injection control and high efficiency stirring apparatus according to the present invention.

* Short description of the major reference marks *

100: mixing apparatus 101: raw water pipe

102: pressure water line 104, 134: valve

105: vertical tube 106: injection tube

107: deflector 130: mixing speed adjusting device

131: strainer 132: variable speed pump

133: the wandering system 135: controller

136: DPT 150: chemical tank

160: flocculation chemical injection pump 170: flocculation chemical injection control device

180, 260: alarm device 171: first pH meter

172: second pH meter 173: sodium hydroxide infusion pump

175: flow current meter 176: microprocessor

200: flocculation device 250: flocculation measuring and adjusting device

300: settler 400: filter paper

W: raw water, W ': pressure water, A: flocculating chemicals, S: light source

100A: inflow zone, 100B: miscification zone, 100C: outflow zone

The present invention relates to a water treatment apparatus and method, and in particular, to improve the existing mechanical rapid mixing device and horizontal paddle stirring type flocculating device used in the conventional water treatment process to the instantaneous mixing device and vertical axis coagulation device in the pipe and At the same time, relatively low demands are placed on chemical mixing and flocculation, which are important for the operation of the water treatment process. Furthermore, improved chemical mixing reduces the removal rate of colloidal particles, natural organic matter (NOM) and disinfection by-product precursors in raw water. The present invention relates to a water treatment apparatus and a method for improving the reliability and ease of maintenance of water treatment by improving the evaluation of an existing chemical injection and aggregation process.

In the present invention, "light scattering analysis value (RMS)" means an effective value (V _RMS ) of the _AC voltage (V _AC ) applied through the AC filter in the light scattering analyzer.

In the present invention, the term "light scattering analysis ratio" refers to an effective value (V _RMS ) of an AC voltage (V _AC ) applied through an _AC filter and a DC voltage (V _DC ) filtered through a DC filter. Means ratio.

Water purification treatment to improve the water quality to suit the purpose of use by using the raw water of the river drift water or appeal is generally composed of water intake, tap water, water purification, water supply, drainage and water supply.

The raw water withdrawn initially is treated with chlorine to secure disinfecting power during the tapping process, and then flows into a mixed paper where flocculating chemicals are injected and rapid stirring is carried out through an impregnating well having a flow control function. Subsequently, the fine floc generated in the blended paper is passed through a flocculating paper which greatly grows to facilitate precipitation, and then passes through a flocculating paper which precipitates the grown floc. Next, after passing through the filter paper to filter the impurities not precipitated in the sedimentation basin, and then go through a purified water in which various pathogenic microorganisms are inactivated by chlorine disinfection.

In this water purification process, in particular, the mixing and coagulation step is composed of a coagulation drug injection, rapid mixing and coagulation process, the overall efficiency is determined by the injection control of the coagulation drug and the mixing and coagulation efficiency.

In relation to the flocculation drug injection control, the injection ratio of the flocculation drug was manually determined by a jar test, which is a kind of model experiment apparatus.

However, this manual method has a big problem that different results are obtained according to the knowledge level and proficiency of the experimenter, that the experiment takes a lot of time and that it is impossible to respond in real time to changes in water quality.

Accordingly, a feedback control technique has been conventionally used to preset the flow current value of the mixed water at the optimum injection of the flocculating chemical and to control the driving of the flocculating chemical infusion pump to reach the set flow current value.

However, this feedback control technique has a problem that the amount of flocculant injected is less than the required amount of flocculant required since the flow current value increases when the pH value of the high turbidity constant raw water of the rainfall falls.

In order to solve the above problems, by inputting the pH value of the mixed water into the proportional controller (PID) and reflecting it to the rotation speed of the coagulation drug injection pump technology to automatically control the coagulation drug injection rate even in the rainy season when the pH value is lowered This is known.

However, this technique has a problem in that even if only the flocculating agent is injected during the purification process, the pH value of the mixed water is limited to a sufficiently high water source.

That is, in the above technique, when the raw water quality of water is clearly distinguished, such as water and rainfall, or when rainy season rainfall, the instantaneous turbidity of the raw water increases by more than 200 NTU, and as the alkalinity decreases, the pH value of the mixed water decreases even below 5.0. The case could not be applied.

Therefore, while controlling the injection of flocculating chemicals in real time, even in the case of raw water changes such as water softeners and precipitation machines, it is possible to efficiently remove turbidity-inducing substances and natural organic substances, thereby obtaining a uniform treated water quality, and overinjecting flocculating chemicals. It is possible to prevent, to minimize the amount of sludge generated and residual aluminum, and to increase the stability of the water treatment process and reduce the cost of the flocculation chemical injection control apparatus or method is required.

On the other hand, in the water treatment system, if there is no monitoring system for monitoring the proper operation of the automatic control type operation system, malfunction of the system can not be confirmed, which may cause deterioration of the treated water quality.

In order to block the possibility of such deterioration of water quality, a coagulation process monitoring and control technique using some equipment such as a particle counter, a pilot filter, and an image analyzer has been studied.

However, in the case of the analysis method using the particle counter, there is a problem that the flocculation floc is broken while passing through the sensor. In addition, since the detection area of most particle counters is at most several hundred micrometers or less, there is a limit in that the formation state of a large floe in the range of 1 to 4 mm, which is largely generated in the flocculation process, cannot be monitored at all.

Even in the analysis method using the shape analyzer, there is a disadvantage in that accurate measurement is difficult for the flow sample, and there is a problem in how to continuously measure the measured data.

In the case of the analytical method using the pilot filter, it is known that it is difficult to apply in high turbidity raw water conditions, and in principle, it is impossible to distinguish between the filterable floc and the precipitated floc, which is inappropriate for monitoring floc sedimentation due to excessive injection of flocculant and poor flocculation. Do.

As such, the conventional flocculation process monitoring method can only grasp the partial characteristics of the flocculation floc, and furthermore, the flocculation flocculum is monitored for the characteristics required in actual operating conditions such as the size, density, and strength of the flocculation floc. No adjustment was made as to how much power was needed.

Accordingly, the present invention is to solve the problems of the prior art as described above, the object of the present invention is to improve the coagulation drug injection in the existing water treatment treatment, further improve the coagulation process evaluation and adjust the coagulation power thereof The present invention provides a purified water treatment apparatus and method which can further improve the reliability and ease of maintenance of purified water treatment.

Water purification apparatus of the present invention for solving the problems as described above, instantaneous mixing device is the raw water is introduced from the impingement well, the flocculating chemical is injected and the instantaneous mixing of the flocculating chemical and the incoming raw water is performed; A flocculating drug injecting and controlling device for injecting a flocculating drug into the instantaneous admixture and controlling the injection thereof; A flocculating device in which mixed water flows from the blending device and agglomeration is performed in the mixed water by stirring the stirring device; And a coagulation measurement and regulating device for measuring the coagulation state in the coagulation apparatus and controlling the coagulation process, wherein the coagulation measurement and regulating device measures the growth state of the flocculation floc by light scattering analysis. A light scattering analysis device for evaluating a change tendency of a value RMS or a light scattering analysis ratio; And the light scattering analysis value RMS or the light scattering analysis ratio when the light scattering analysis value RMS or the light scattering analysis ratio tends to fall or remain constant. Characterized in that consisting of; stirring power control device for adjusting the stirring power of the stirring device.

The instantaneous admixture measures the flow rate of either or both of the raw water or the pressurized water, and in response to the measured value, is discharged from the flow of raw water and pressurized again into the raw water and sprayed with the flocculating chemicals. It is preferable to further include an adjusting device for adjusting the instantaneous mixing strength by adjusting the flow rate of the pressure water.

The instantaneous mixing device, the raw water pipe; A pressure water line flowing out of one side of the raw water pipe and then flowing back into the raw water pipe; A vertical pipe connected to the pressure water line and vertically installed in the raw water pipe; A pressure water and agglomeration chemical injection pipe connected to the vertical pipe, in which pressure water flows and agglomeration chemicals flow so as not to mix with the pressure water, and a deflector is provided at an end thereof; A flow meter installed in the pressure water line; A variable speed pump installed in the pressure water line; And a controller connected to the flowmeter and the variable speed pump, respectively, and controlling the pumping speed of the variable speed pump in response to the pressure water flow rate of the pressure water line.

The flocculation drug injection and control device, flocculation drug injection device for injecting flocculation drug into the raw water; A flow current measuring device for measuring a flow current of the mixed water; And a coagulation drug injection control device for controlling the coagulation drug injection so that the flow current value has a set value or is in a set range corresponding to the measured flow current value.

The flocculation drug injection and control device, the first pH meter for measuring the pH of the raw water; A second pH meter for measuring pH of the mixed water; And an alkali adjuvant injector for injecting an alkali adjuvant into the raw water such that the pH value of the first pH meter and the pH value of the second pH meter are each within a set range or have a set value.

The flocculation drug injection and control device, the first pH meter for measuring the pH of the raw water; A second pH meter for measuring pH of the mixed water; An alkali adjuvant injector for injecting an alkali adjuvant into the raw water; A flocculating chemical injector for injecting flocculating chemical into the raw water; A flow current meter for measuring the flow current of the mixed water; A wired or wireless connection to the first pH meter, the second pH meter, the flow current meter, the flocculating drug injector, and the alkali adjuvant injector, respectively, in real time corresponding to the measured flow current value. Adjust the flocculation drug injection to be within the set range or to have a set value, and the pH value of the raw water and the pH value of the mixed water are respectively corresponding to the measured pH value of the raw water and the pH value of the mixed water in real time. It is preferable to include; a microprocessor for controlling the injection of the alkali adjuvant to be within a set range or to have a set value.

The microprocessor continues the flocculation drug injection as before when the absolute value or relative reference value of the measured flow current value is zero, and when the absolute value or relative reference value of the measured flow current value is less than zero. It is desirable to increase the flocculation drug injection and to reduce flocculation drug injection if the absolute or relative reference value of the measured flow current value is greater than zero.

The microprocessor preferably controls the injection of the alkali adjuvant such that the pH value of the raw water is less than 8.0 and the pH value of the mixed water is within a range of 6.5 or more. At this time, the pH value of the raw water is more preferably less than 7.5.

Preferably, the alkali adjuvant is sodium hydroxide.

The agitation device of the flocculation device includes a driver; A vertical drive shaft connected to the driver; It is preferably configured to have a fallopian tube shape that is connected to the vertical drive shaft and gradually expands from the top to the bottom, and an impeller in which a spiral transmission feather is disposed radially on the fallopian tube.

The agglomeration apparatus is composed of a plurality of unit agglomeration paper continuously, the agglomeration measuring and regulating device, the light scattering analysis value (RMS) or the light scattering analysis ratio (ratio) is in the unit agglomeration paper or the unit agglomeration paper If the stirring power is constant over the unit flocculation papers, if the stirring power is constant over the unit flocculation papers, the stirring power at the unit flocculation paper or the unit flocculation papers showing the holding tendency is lowered, or the unit If the agitation power has been reduced across the flocculation papers, it is desirable to increase the agitation power at the unit agglomeration paper or the agglomeration papers showing the holding tendency.

The flocculation measurement and control device is preferably connected to the precipitation turbidity measurement device for measuring the precipitation turbidity of the treated sedimentation water from the flocculation device to reflect the precipitation turbidity measurement results when the flocculation process is adjusted.

The agglomeration apparatus is composed of a plurality of unit agglomeration paper continuously, wherein the agglomeration measuring and regulating device, the light scattering analysis value (RMS) or the light scattering analysis ratio (ratio) in the unit agglomeration paper or the unit agglomeration paper The unit agglomeration paper or the unit showing the tendency to fall if the tendency to descend over, and the agitation power has been reduced across the unit flocculation papers, it is necessary to lower the precipitation turbidity input from the precipitation turbidity measuring device. If it is not necessary to lower the stirring power in the flocculating papers or lower the precipitation turbidity, it is desirable to increase the stirring power in the unit flocculating paper or the unit flocculating papers showing the downward tendency.

When the precipitation turbidity is less than one value selected between 1 and 1.5 NTU, it is preferable to determine that it is not necessary to lower the precipitation turbidity, and when higher than the value, it is preferable to determine that it is necessary to lower the precipitation turbidity.

It is preferable that the water treatment apparatus evaluates the change tendency of the light scattering analysis value (RMS) or the light scattering analysis ratio (ratio) in a state in which the flocculation chemical injection amount is adjusted so that floc growth is good, and the flocculation chemical injection and alkali It is more preferable to evaluate the tendency of the light scattering analysis value (RMS) or the light scattering analysis ratio (ratio) in parallel with the addition of the adjuvant.

The purified water treatment method of the present invention for solving the problems as described above, the instantaneous mixing step (S1) for introducing the raw water from the impingement well, injecting the flocculating chemicals and performing instantaneous mixing of the flocculating chemicals and the incoming raw water; Aggregate drug injection control step (S2) for controlling the injection of the flocculation drug; An agglomeration step (S3) for carrying out agglomeration through mixed water; And measuring the aggregation state and controlling the aggregation process in response to the measured result, measuring the growth state of the flocculation floc by light scattering analysis, and evaluating the tendency of the light scattering analysis value (RMS) or the light scattering analysis ratio. If the light scattering analysis value (RMS) or the light scattering analysis ratio (ratio) tends to fall or remain constant, so that the light scattering analysis value (RMS) or the light scattering analysis ratio (ratio) tends to increase It characterized in that it comprises a; a coagulation measurement and adjustment step (S4) for adjusting the stirring power during the coagulation.

In the step S1, the flow rate of any one or two of the raw water or the pressure water is measured, and in response to the measured value, the pressure is discharged from the flow of the raw water and pressurized to flow back into the raw water and sprayed with the flocculating chemicals. By adjusting the flow rate of water, it is preferable to adjust the said instantaneous mixing intensity.

In the step S2, it is preferable to measure the flow current of the mixed water and control the flocculation chemical injection so that the flow current value has a set value or is in a set range in response to the measured flow current value.

In step S2, the pH value of the raw water is measured, the pH value of the mixed water is measured, and the pH of the raw water and the pH value of the mixed water are each injected with an alkali adjuvant to be within or within the set range. It is preferable to further include.

In step S2, the pH value of the raw water is measured, the pH value of the mixed water is measured, and the pH value of the raw water and the pH value of the mixed water are respectively within a set range in response to the measured pH values in real time. Injecting an alkali adjuvant into raw water to have a set value (S2-1); And measuring the flow current of the mixed water and injecting the flocculating agent injecting the flocculating drug such that the flow current value is within a set range or has a set value in real time corresponding to the measured flow current value (S2-2). It is preferable to include;

In step S2-1, the pH value of the raw water is less than 8.0, and the pH value of the mixed water is controlled to be controlled so that the alkali adjuvant is within the range of 6.5 or more, wherein the pH value of the raw water is 7.5 It is more desirable to make it smaller.

In step S2-2, when the absolute value or relative reference value of the measured flow current value is 0, the flocculation drug injection is continued as before, and the absolute value or relative reference value of the measured flow current value is smaller than 0. In the case of increasing the flocculation chemical injection, it is desirable to reduce the flocculation chemical injection when the absolute value or relative reference value of the measured flow current value is greater than zero.

Wherein the step S2, if the pH value of the raw water is less than 7.5 continues the injection of the alkali adjuvant as before, and if the pH value of the raw water is less than 7.5 the pH value of the raw water to reduce the injection of the alkali adjuvant (S2 -1a); After the step S2-1a, when the absolute value or the relative reference value of the measured flow current value is 0, the flocculation drug injection is continued as before, and the absolute value or the relative reference value of the measured flow current value is smaller than 0. Increasing the flocculation drug injection in the case of reducing the flocculation drug injection when the absolute value or the relative reference value of the measured flow current value is greater than zero (S2-2); And after the step S2-2, if the pH value of the mixed water is less than 6.5 to increase the injection of the alkali adjuvant, and if the pH value of the mixed water is 6.5 or more to continue the injection of the alkali adjuvant as before (S2-1b It is preferable to consist of;

In the above water treatment method, the alkali adjuvant is preferably sodium hydroxide.

In the purified water treatment method, the aggregation step is performed continuously through a plurality of unit aggregation processes, and the light scattering analysis value (RMS) or the light scattering analysis ratio (ratio) is applied to the unit aggregation process or to the unit aggregation processes. If the stirring power is constant over the unit agglomeration processes, the stirring power in the unit agglomeration process or the unit agglomeration processes showing the holding tendency is lowered, or If the stirring power has been reduced over the unit agglomeration processes, it is desirable to increase the agitation power in the unit agglomeration process or the unit agglomeration processes that exhibit the retention tendency.

In the purified water treatment method, the aggregation step is performed continuously through a plurality of unit aggregation processes, and the light scattering analysis value (RMS) or the light scattering analysis ratio (ratio) is applied to the unit aggregation process or to the unit aggregation processes. If there is a tendency to fall over and the agitation power has been reduced over the unit flocculation processes, the unit flocculation process or the corresponding unit tends to fall, if it is necessary to lower the precipitation turbidity of the treated sediment through the flocculation process. If it is not necessary to lower the agitation power in the unit flocculation processes, or to lower the precipitation turbidity of the sediment treated in the unit flocculation process, it may be necessary to increase the agitation power in the unit flocculation process or the unit agglomeration processes showing the downward tendency. desirable.

When the precipitation turbidity is less than one value selected between 1 and 1.5 NTU, it is preferable to determine that it is not necessary to lower the precipitation turbidity, and when higher than the value, it is preferable to determine that it is necessary to lower the precipitation turbidity.

In the purified water treatment method, it is preferable to evaluate the tendency of the light scattering analysis value (RMS) or the light scattering analysis ratio (ratio) in a state in which the flocculation chemical injection amount is adjusted so that floc growth is good, and the flocculation chemical injection and alkali It is more preferable to evaluate the tendency of the light scattering analysis value (RMS) or the light scattering analysis ratio (ratio) in parallel with the addition of the adjuvant.

Hereinafter, an apparatus and a method for treating water purifying according to the present invention will be described in detail through examples. However, the present invention is not limited to the following specific examples, only the following examples are intended to facilitate the implementation of the invention to those skilled in the art while at the same time making the disclosure of the present invention complete, and also Various modifications are possible within the scope of the appended claims.

In the present invention, it is very difficult to determine whether the flocculation process is properly operated in the purified water treatment plant in the case of the conventional water treatment plant treatment method or method, and accordingly, the light scattering analyzer has been previously considered in view of the fact that the flocculation process could not be properly controlled. Unlike the optical monitoring technique (PDA), which is only used to determine the flocculation chemical dosage, it is used to control the agitation power (G) of the flocculation paper, which effectively measures and adjusts the flocculation state, thereby greatly increasing the efficiency of the flocculation process. Let's do it.

Fig. 1 is a schematic diagram schematically showing the configuration of another water treatment apparatus in one embodiment of the present invention.

As shown in FIG. 1, the apparatus according to one embodiment of the present invention includes an instantaneous mixing device in which raw water W is introduced from an impingement well, coagulated chemical is injected, and instantaneous mixing of the coagulated chemical and inflowing raw water is performed. 100), the mixing speed control device 130, the instantaneous mixing device 100 is connected to the instantaneous mixing device 100 to adjust the instantaneous mixing speed by adjusting the injection speed of the flocculating chemicals corresponding to the flow rate of raw water A chemical tank 150 for injecting a coagulated drug into the coagulation drug injection pump 160, a coagulation drug injection control device 170 for controlling the pump 150, and the instantaneous mixing device 100 connected to the instantaneous The flocculating apparatus 200 includes a flocculating apparatus 200 in which mixed water flows from the blending apparatus 100 and agglomeration is performed by agitation, and a flocculation measuring and regulating apparatus 250 for measuring and adjusting the coagulation state in the flocculating apparatus. And, typically, the settling basin 300 is connected to the flocculating apparatus 200, and the filter set 400 is connected to the settling basin 300. Furthermore, the flocculation drug injection control device 170 or the flocculation measurement and regulating device 250 are connected to alarm devices 180 and 260 for informing the alarm when there is an abnormality in the control or adjustment state. In addition, a precipitation turbidity measurement device (not shown) may be further connected to the aggregation measurement and control device 250 so as to receive information on precipitation turbidity of the treated water after the aggregation process from the aggregation device, as described below.

Specifically, the mixing device 100 including the instantaneous mixing speed adjusting device 130 preferably has the following configuration.

2A is a schematic diagram showing an instantaneous admixture according to an embodiment of the present invention.

As shown in FIG. 2A, the instantaneous mixing device 100 flows from the one side of the raw water pipe 101 to the raw water pipe 101 after the pressure water line 102 has passed through the valve 104. . The pressure water line 102 is connected to a strainer 131 for filtering foreign matters, and then a variable speed pump 132 is connected, and a flow meter 133 is connected after the valve 134. Meanwhile, a controller 135 is connected to the variable speed pump 132 and the flow meter 133, respectively. Furthermore, a DPT 136 connected to the controller 135 may be installed around the strainer 131. If a blockage occurs in the strainer 131 during the continuous operation, a pressure difference occurs before and after the strainer 131. The DPT 136 checks whether the strainer is blocked by receiving a pressure signal at the front and rear ends of the strainer 131 and measuring the difference between the initial operation and the pressure during operation.

The pressure water line 102 is connected through the valve 104 to a vertical pipe 105 which is installed vertically in the raw water pipe 101 and into which the flocculating chemicals from the flocculating chemical pump 160 are injected. At the end of the straight pipe 105, the injection pipe 106 of the flocculating chemicals and the pressure water is provided with a deflector (107) to maximize the dispersion in the pipe.

FIG. 2B is a schematic diagram showing the flow in the injection pipe of FIG. 2A together with the deflector. FIG.

As shown in FIG. 2B, in the injection pipe 106, the flocculating chemicals A flow separately so that they do not mix with the pressure water W ′, and the respective flows are injected while colliding at the deflector 107, and thus raw water Instantaneous mixing of and flocculating chemicals occurs. On the other hand, factors such as the size, shape, distance from the nozzle, the method of ejecting pressure water, etc. of the deflector 107 affects the dispersion efficiency, so that the factor is adjusted to increase the efficiency.

In this way, instantaneous mixing of the flocculating chemicals and the raw water from the landing well is performed (S1). In the present invention, in particular, to analyze the flow rate of the raw water (and / or pressure water flowing out of the raw water) as described above and to adjust the instantaneous mixing strength, such as to control the injection in response to this, according to this configuration, precipitation of the flocculating chemicals However, clogging of the injection device due to the use of high turbidity pressure water can be avoided. Furthermore, complete mixing is possible within a time of 1 second, thereby achieving instantaneous mixing of high efficiency.

Figure 3a is a schematic diagram showing a coagulation drug injection control device according to an embodiment of the present invention.

As shown in FIG. 3A, the raw water W passes through the inflow area 100A, the mixing area 100B, and the outflow area 100C (of course, in the outflow area, it is discharged as mixed water), and the inflow area A first pH meter 171 (measured pH value corresponds to pH _P of FIG. 3C) is connected to 100A for measuring the pH of raw water, and a second pH for measuring the pH of mixed water is connected to the outflow area 100B. The pH meter 172 (measured pH value corresponds to pH _S of FIG. 3C) is connected, and the pH value measured from the first pH meter 171 and the second pH meter 172 is microwired or wirelessly. Input to the processor 176.

On the other hand, a sodium hydroxide infusion pump 173 (corresponding to P _N in FIG. 3C), which is also an alkali adjuvant, is connected to the inflow region 100A, and a coagulated chemical infusion pump 160 (corresponding to P _C in FIG. 3C) is connected. A flow current meter 175 (the measured value corresponds to the SPD of FIG. 3C) is connected to the outlet area 100B. The sodium hydroxide infusion pump 173, the flocculant injection pump 160, and the flow current meter 175 are also connected to the microprocessor 176 by wire or wirelessly, respectively.

The microprocessor 176 corresponds to the sodium hydroxide infusion pump 173 and the coagulant injection pump 160 in real time based on the pH value of the raw water, the pH value of the mixed water, and the flow current value measured in real time. Control the number of revolutions. This is further described in detail with reference to FIG. 3C.

3B is an enlarged schematic view of the structure of the flow current meter of FIG. 3A.

As shown in FIG. 3B, the flow current meter 175 includes a probe 175-4 formed at a position where the inlet 175-1 and the outlet 175-2 face each other. The piston 175-3 is provided inside the probe 175-4, and the piston 175-3 strongly flows the sample introduced into the probe 175-4 while reciprocating up and down by the water flow shear force. Separate the counterion bound to the charged particles in the sample to generate a flow current. On the other hand, two electrodes 175-5 on the inner wall of the probe 175-4 which detect the flow current generated by the reciprocating motion of the piston 175-3 and output it to the computing device 175-6. It is provided. The computing device 175-6 is connected by wire or wirelessly to the microprocessor 176 as shown in FIG. 3A.

For reference, when the flow current measuring principle is described in detail, generally, a substance causing turbidity in stream drift water has a negative charge, and a flocculant injected with a negative charge has a positive charge, and the turbidity causing substance has a positive charge around the particle. To form an ion layer. The ion layer is divided into a fixed layer and a diffusion layer (electrical double layer theory), thereby allowing the measurement of the flow charge or the flow current by charge flow by particle separation from the diffusion layer. Therefore, when the flow current is higher than the absolute value or the relative reference value, the coagulant drug is excessively input, and when the flow current is lower than that, it may be determined that the coagulant drug is insufficient.

Specifically, the aggregation drug injection control (S2) process will be described below.

3C is a flow chart showing an example of a logic configuration for performing coagulation drug injection control in the present invention.

As shown in FIG. 3C, first, the starting values of the rotation speeds of the flocculation chemical injection pump P _c and the sodium hydroxide injection pump P _N are input, and the pH of raw water (pH _P ) and the pH of mixed water ( pH _S ) and flow current value (SPD) are read respectively. If the raw water pH (pH _P ) value is less than 7.5, the flow proceeds to the next step while maintaining the rotational speed of the sodium hydroxide injection pump (P _N ), and if the pH _P value is more than 7.5, the sodium hydroxide injection pump (P The pH _P value is adjusted to be less than 7.5 by reducing the number of revolutions of _N ) to reduce the sodium hydroxide infusion. On the other hand, if the flow current value SPD expressed as an absolute value or a relative reference value from the flow current meter is 0, the rotation speed of the coagulation chemical injection pump P _C is maintained as it is and the process proceeds to the next step. When the flow current value SPD is less than zero, the rotation speed of the flocculation chemical injection pump P _C is increased to increase the flocculation chemical injection amount, and when the flow current value SPD is larger than 0, the flocculation chemical The injection speed of the injection pump (P _C ) is reduced to reduce the amount of coagulant injection. Subsequently, when the pH (pH _S ) value of the mixed water is smaller than 6.5, the rotation speed of the sodium hydroxide injection pump (P _N ) is increased, and if the pH _S value is 6.5 or more, the rotation of the sodium hydroxide injection pump (P _N ) is performed. Keep the numbers and go to the last step. At the last stage, if the control system is operating normally, the "ON" signal is displayed and the process goes back to the first reading stage.

When the pH of the mixed water was less than 6.5, the turbidity removal efficiency was decreased by increasing the residual turbidity of the precipitated water. At this time, the residual turbidity of the precipitated water was further reduced because the pH of the mixed water was further decreased even when the flocculation chemical injection rate was increased. Cannot be kept good.

Meanwhile, as described above, in FIG. 3C, for example, the pH value of the raw water is set based on 7.5, which is not necessarily limited to 7.5 and may be extended to 8.0.

Specifically, even if the pH of the mixed water is fixed, the addition of the coagulated drug injection and the addition of the alkali adjuvant causes a problem of additional injection of sodium hydroxide, which is an alkali adjuvant for increasing the pH and the lowered pH of the mixed water due to the coagulation drug injection. (This is a kind of logical conflict or error in automatic control logic). In order to solve this problem, the upper limit of raw water pH should be set.

That is, the pH of the alkali adjuvant is increased, and in this case, the SPD is lowered. When the flocculation drug is injected according to the decrease of the SPD, the pH of the flocculating drug is about 4, so the pH is lowered so that the injection of the alkali adjuvant is added. Logical conflicts leading to errors occur. In order to prevent this, the pH of the raw water should be set to be less than a constant value. If the constant value is selected between 7.5 and 8.0, the pH of the mixed water can be controlled to 6.5 or more as described above.

Specifically, the result of evaluating the flocculation drug injection and control process as described above by installing the pilot device according to the present invention and taking the raw water as shown in the following [Table 1]. Here, sodium hydroxide, an alkali adjuvant for pH control of the raw water withdrawn, was used by dissolving a commercially available special reagent in distilled water, and as the flocculant, poly aluminum chloride (hereinafter referred to as "PACl") ) Was used. The treatment capacity of the intake of raw water was 1,000 m ³ / day and the target pH of the raw water and the mixed water was set to less than 7.5 and 6.5 or more, respectively. The rotation speed was adjusted.

In addition, Table 1 shows the characteristic of the said raw water.

division Turbidity (NTU) pH Water temperature (℃) Current value (mV) range 4.8 ~ 61.5 6.73-8.89 3.4-22.9 -0.40--0.51

First, FIG. 4 is a graph showing the correlation (a) between the injection rate of the flocculant (expressed as flocculant in FIG. 4) and the flow current value (SPD) and the residual turbidity of the precipitated water (b).

As can be seen from Figure 4, in the case of raw water turbidity 17.9 ~ 21.4 NTU it was found that the flow current measurement for each flocculation chemical injection increases linearly when the flocculation chemical input is increased by 10 ppm. Since the flow current value indicates 0 between 30 ppm and 35 ppm of the flocculating chemical input concentration, this value is the optimum flocculating chemical dosage. On the other hand, the residual turbidity tended to decrease with the increase in the amount of flocculation drug.

On the other hand, Figure 5 shows the automatic control of the flocculation drug injection rate according to the raw water turbidity change ("automatic control" as described above corresponding to the flow current measurement, that is, the coagulation drug injection based on the flow current measurement value in the logical operation Therefore, it means automatic control.) Continuously so that the amount of coagulated chemical injection is controlled automatically by the flow current value without pH adjustment for raw water with pH 7.5 or higher and turbidity of 10 NTU that does not require pH adjustment of mixed water to evaluate the performance. It is a graph showing the result when driving.

As can be seen from Figure 5, the pump (pump,%) of the flocculation chemical injection pump reacted very closely with raw water turbidity to maintain the set value of the flow current value 0. At the same time, mixed water was collected and subjected to a jar test, followed by coagulation sedimentation, and the residual turbidity was measured. As a result, it was confirmed that the sediment water was stably produced below 1.0 NTU.

On the other hand, Figure 6 is a flow current value without pH adjustment for raw water of less than pH 7.5, turbidity 40 NTU required to adjust the pH of the mixed water in order to evaluate the automatic control performance of the flocculation drug injection rate according to the turbidity and pH change of rainfall It is a graph which shows the result at the time of continuous operation so that the amount of coagulation | flocculant injection | pouring by the control may be automatically controlled.

Although the pH of raw water was maintained at about 7.0, the pH of the mixed water showed a tendency to decrease to at least 5.0, and the turbidity was removed in the range of 2 to 4 NTU as a result of examining the residual turbidity of the sample water collected after agglomeration and precipitation by mixing the mixed water. The efficiency was very low.

Thus, in case of rainfall, the reason why the pH tends to decrease sharply is different from that in the case of the normal season. The amount of flocculation chemicals is increased due to the increase of turbidity during rainfall, and the injected flocculation chemicals lower the pH of the mixed water, and the alkalinity is sufficient. This is because the decrease in pH of the mixed water during the rainy season does not increase significantly.

6 also shows that immediately after the addition of the alkali adjuvant sodium hydroxide, the pH of the mixed water and the revolution (pump,%) of the coagulant injection pump rise simultaneously, with the flow current value decreasing. This means that the pH of the mixed water is a very important factor in the automatic control of the flocculation chemical injection rate by the flow current value, and furthermore, the addition of an alkali adjuvant for adjusting the pH of the mixed water is very important.

On the other hand, Figure 7a is a pH adjustment for the raw water of less than pH 7.5, turbidity of 35 NTU, the pH of the mixed water is required to evaluate the automatic control performance of the flocculation drug injection rate according to the turbidity and pH change of the rainy season raw water turbidity and pH flow It is a graph which shows the result at the time of continuous operation so that the amount of flocculation chemical injection by an electric current value may be automatically controlled.

Due to the characteristics of the surface water in Korea, which has high turbidity during the summer rainy season, it can be seen that the pH of the mixed water should be adjusted to an appropriate cohesive pH range by injecting sodium hydroxide for alkali supplementation during the rainfall period. In particular, the pH of the mixed water is automatically adjusted to 6.5 or more by adding sodium hydroxide from FIG. 7 ("automatic adjustment" means automatically adjusting the rotational speed of the pump of sodium hydroxide in accordance with the logical operation device in response to the pH measurement). In this case, the effect of the flow current value on the automatic control of flocculation chemical injection amount can be seen. Before adjusting the pH of the mixed water, the residual turbidity of the precipitated water after coagulation precipitation is investigated to 2.0 NTU or more as shown in FIG. However, when it was automatically controlled by the addition of sodium hydroxide, the residual turbidity of the precipitated water after the flocculation precipitation ensured a very good water quality of 1.0 NTU or less.

7B and 7C are graphs showing the relationship between pH and turbidity of mixed water and the relationship between pH, turbidity, and flocculation chemical injection rate of mixed water, respectively, when JA test was performed on rainfall-high turbidity (25.9 to 31.9 NTU) raw water. (Coagulant injection rate is 20 ppm).

As shown in Figures 7b and 7c, when the pH of the mixed water is less than 6.5, the residual turbidity of the precipitated water was increased to reduce the turbidity removal efficiency, and at this time, the pH of the mixed water is increased even though the flocculation chemical injection rate is increased. The sediment residual turbidity could not be maintained very well below 1.0 NTU because of further decreases. Therefore, the pH range of the mixed water for optimal flocculation is set to 6.5 or more, on the other hand, in order to solve the logical error that may occur between the lowering of the mixed water pH caused by the flocculation chemical injection and the injection of sodium hydroxide to raise the lowered pH. While maintaining the pH of the raw water before the flocculation drug injection to the upper limit, the constant value is set to be selected between 7.5 and up to 8.0.

As described above, the method of controlling the rotational speed of the sodium hydroxide infusion pump to adjust to the optimum pH for aggregation is particularly suitable for the water treatment process using the surface water source is severe seasonal changes in water quality. That is, according to the above method, it is possible to prevent the precipitation water degradation and the excessive injection of flocculant due to the increase in precipitation turbidity of the raw water turbidity and the pH decrease caused by the water purification plant in which the plain water and the rainfall are clearly distinguished. It is economical and effective because it can be simply added without use.

FIG. 8A is a schematic view showing a vertical axis stirring device of the high efficiency flocculation device used in the present invention, and FIG. 8B is a schematic view showing the flow of treated water in the flocculation device using the stirring device.

As shown in FIGS. 8A and 8B, the stirring device of the flocculating device 200 has a vertical drive shaft 201 connected to the driver 203 and gradually expands from the top to the bottom connected to the vertical drive shaft 201. It consists of an impeller 202 formed radially, for example, protruding radially on the fallopian tube-shaped surface having a diameter to be made. According to such an impeller 202, there is no turbulence generation, thereby forming a flow 204 which does not destroy flocs during the flocculation process and can effectively eliminate flocculation. In addition, it is very economical to provide efficient stirring conditions at low power costs, such as to minimize the dead zone by transferring the stirring energy evenly in the aggregate.

On the other hand, the aggregation measurement and control device 250 is a light scattering analysis device and the light scattering analysis value (RMS) to measure the growth state of the flocculation floc to evaluate the change in light scattering analysis value (RMS) or light scattering analysis ratio (ratio) Or a stirring power regulating device that adjusts the stirring power of the stirring device so that the light scattering analysis ratio is inclined to rise when falling or in a tendency to remain constant.

Specifically, floc formation during the flocculation process is very important, in which flocculation, ie, sinking, decreases the efficiency of flocculation, and in the event of flocculation, the load may increase during precipitation or filtration. Therefore, in the present invention, the light scattering analysis device and the stirring power control are performed to control and regulate the generation of flocs, such as controlling the flocculation and destruction of the flocs.

The light scattering analyzer aggregates through the effective value (V _RMS ) of the AC voltage (V _AC ) filtered through the AC filter or the ratio (Ratio) of the effective value and the DC voltage (V _DC ) filtered through the DC filter. The floc growth status will be displayed.

9 is a view showing a light scattering analysis concept of the light scattering analysis device of the present invention.

As shown in FIG. 9, it indicates that light passes from the light source S through the agglomeration floc circulation tube 253 in the light scattering analyzer. The light passing through the floc circulating tube 253 represents two waveforms, a waveform representing an irregular variation of the floc particles and a waveform representing the intensity of light, and these two waveforms represent an alternating voltage (V _AC ) and a direct current voltage (V). _It is converted into two electrical signals of _DC ). Then, the ratio of V _RMS (hereinafter referred to as "RMS"), which is the effective value of the AC voltage V _AC , to DC voltage V _DC (hereinafter referred to as "ratio"); As shown below, the ratio is an indicator of flocculation, and in this sense the ratio can be expressed as a locator index (FI)] is calculated as follows.

In [Equations 1] and [Equation 2], V is the measured AC voltage, A is the effective cross-sectional area of the light, L is the diameter of the cross-circulation pipe flow, n is the particle number concentration, C is the particle dispersion cross-section, Ni Is the particle number concentration of size class i, and Ci is the particle dispersion cross section of size class i.

On the other hand, Figure 10 is a basic experiment to examine the change in the RMS and ratio for the coagulation drug injection, RMS and ratio measured as a result of the aggregation (30rpm, 30min) and precipitation (30 min) experiment of the Jar test A graph representing.

As can be seen in Figure 10, in the case of mixed water before the start of the aggregation can be seen that the RMS or ratio is kept constant while rising rapidly at the same time as the aggregation begins. On the other hand, during aggregation, the RMS or especially the ratio increases rapidly and then decreases slightly. This means that flocs are produced early in the flocculation but break up rather than grow over time. In other words, in floc, floc repeats collision and destruction through flocculation process. If flocculation growth is predominant, RMS or ratio continues to rise, but breakup is predominant. In this case, the RMS or ratio decreases. This means that if the floc grown by excessively charged stirring power is destroyed, the RMS or ratio decreases and the precipitation efficiency becomes very low.

11 is a graph showing a ratio pattern in the case of monitoring or controlling a flocculation process using a light scattering analyzer, and by analyzing such a pattern, stirring power in the flocculation process can be controlled.

In detail, as illustrated in FIG. 11, when flocculated water is agglomerated in the water purification process, flocs may be generally expressed in four degrees (I, II, III, and IV).

First, in the case of the I and II patterns, it means that the floc grows gradually up to the point of precipitation, and thus, in this case, the energy (G) value required for the flocculation process can be evaluated as appropriate.

On the other hand, in the case of III and IV, the flocs of the initial flocculation process increase rapidly, but the grown flocs are in parallel with the growth and destruction (in the case of III), or they are no longer grown and the flocs are destroyed (in the case of IV). This pattern indicates that the stirring gradient (G, velocity gradient) applied in the coagulation process is not appropriate.

In short, the ratio pattern measured by the light scattering analysis rises, rises, and becomes constant, rises, or falls, whereby it is possible to maintain the rising pattern by adjusting the stirring power, thereby achieving good precipitation. It can be achieved. As such, the aggregation process may be evaluated in real time by light scattering analysis, and the aggregation process may be controlled by controlling the degree of the input stirring power in real time.

On the other hand, the factors affecting floc formation in the flocculation process include physicochemical characteristics such as agitation power, pH of raw water, and water temperature in addition to the agitation power. same.

Prior to evaluating the floc formation characteristics according to the flocculant injection amount, first, the change characteristics of RMS and ratio through the Jar test flocculation precipitation experiment after the instantaneous admixture were examined.

FIG. 12 is a graph showing turbidity and streaming potential (SP) change according to agglutination agent (using PAC) in the ruler test.

As can be seen in Figure 12, the SP of the mixed water increases as the amount of flocculation chemical injection increases. On the other hand, at this time, as a result of performing a coagulation precipitation experiment using the Jar test by taking each mixed water, it was found that the turbidity removal rate was greatly increased when the coagulation drug injection amount was about 6 mg / L.

FIG. 13 is a graph showing change characteristics of RMS (a) and ratio (b) during agglomeration precipitation in the Jar test experiment used in FIG. 12.

As can be seen in Figure 13, it can be seen that the characteristics of the RMS and ratio changes at the same time as the turbidity or SP of Figure 12 as the amount of flocculation drug injection increases. Again, increasing RMS and ratio means floc growth. As the floc growth change pattern changes as the flocculation time changes during the treatment of the flocculating chemicals, it is necessary to take this into consideration when controlling the stirring power through the light scattering analysis (RMS, ratio).

That is, according to FIG. 13, floc formation was accelerated under the condition of the highest amount of flocculant injection amount (18.0 mg / L), but the grown flocs decreased in both RMS and ratio during the flocculation process. This means that the floc is breaking down and that the stirring energy used for the flocculation process is excessively used under relatively excessive flocculation chemical injection conditions.

On the other hand, when the flocculant injection amount is 12.5 mg / L it can be seen that the floc is growing well as the flocculation time has elapsed, and it can be seen that the precipitation is rapidly settling at the same time as the precipitation process starts.

When the stirring power is adjusted through the light scattering analysis as described above, it is preferable to adjust the stirring power based on the light scattering analysis result (RMS, ratio) after selecting the flocculant injection amount so that the floc growth is good.

FIG. 14 illustrates a coagulation pattern (ratio pattern) when the stirring power is changed in the case of controlling the coagulation drug injection amount using only SP in the instantaneous admixture. When the injection amount is increased or when the pH decreases rapidly due to lack of alkalinity, the floc formation pattern is shown by changing the stirring power to E1, E2, E3, E4 and E5.

Table 2 shows the conditions of the above experiments (E1, E2, E3, E4 and E5).

Party Test Coagulation RPM for 30 minutes (min-min-min) Coagulant Injection Raw water turbidity Ruler test flocculation sediment Sampling time Turbidity Zeta Potential E1 30-20-10 8.6% 70 2.26 -2.7 37 minutes E2 30-30-30 7.8% 57.5 2.65 -3.0 127 minutes E3 10-20-30 8.2% 53.1 3.53 -2.4 187 minutes E4 20-20-20 8.2% 61 4.63 -2.6 277 minutes E5 30-30-30 10.2% 68.1 51.0 -9.3 389 minutes Alkaline addition SP = -0.3

The floc formation pattern as shown in FIG. 14 shows that the flocculation chemical injection failed due to instantaneous mixing, and it can be seen that the flocculation pattern is almost independent of the stirring power (or rpm) change in the flocculation process.

As can be seen in Figure 14, the case of controlling the amount of flocculation drug injection using only the SP is that the absolute value of the SP itself has a characteristic that changes with the pH. Therefore, in case of automatic control using SP, the pH of the constant raw water has an absolute effect on the amount of injected flocculating chemicals. In the case of domestic water purification plant, high turbidity flows temporarily during the rainy season, at which time an excessive amount of coagulant is required. Therefore, when the alkalinity is not sufficient, the pH decrease is noticeable, and the absolute value of SP tends to be evaluated to be somewhat lower than the value of neutral pH. In this case, agglomeration is not well achieved, and only non-colloidal and large particles are precipitated, and colloidal particles hardly precipitate, which tends to increase turbidity of the precipitated supernatant. In such a case, therefore, an alkali coagulant (for example, sodium hydroxide) can be added to the raw water to prevent the underestimate of flocculant injection amount.

Figure 15 shows a coagulation pattern (ratio pattern) while varying the stirring power (E1, E2, E3, E4) when the mixture was instantaneously mixed with instantaneous injection of sodium hydroxide (NaOH 20%) into the raw water and SP control. Here, the amount of sodium hydroxide injected is important, but the pH was injected to maintain the pH of about 6.5 ~ 6.8 after instantaneous mixing.

Table 3 shows the conditions of each experiment (E1, E2, E3 and E4).

Party Test Coagulation RPM for 30 minutes (min-min-min) Coagulant Injection Raw water turbidity Ruler test flocculation sediment Sampling time Turbidity Zeta Potential E1 30-20-10 8.2% 33.5 2.1 -3.2 47 minutes E2 30-30-30 7.2% 33.6 1.04 -6.5 104 minutes E3 10-20-30 8.6% 39.1 1.45 -3.5 157 minutes E4 20-10-5 8.6% 37.6 4.3 -4.0 205 minutes

As shown in FIG. 15, unlike in the case of FIG. 14, it can be seen that the floc formation pattern is changed according to the stirring power, and the floc formation and precipitation patterns are clearly distinguished according to the aggregation time.

As such, in the present invention, in addition to controlling the flocculating agent by the SP during injecting the flocculating agent, a floc formation pattern suitable for controlling agitation power can be obtained, in particular, in the case of maintaining a constant degree of alkalinity using an alkali adjuvant such as sodium hydroxide. It can be seen that.

On the other hand, it is relatively difficult to determine the pattern of floc growth because it is a continuous operation in the actual process, but in each unit coagulation process (for example, 1, 2, and 3 papers), the floc characteristics can be identified in a stable state. When the continuous process is performed through a plurality of unit aggregation processes as described above, the light scattering analysis value (RMS) or the light scattering analysis ratio (ratio) is constant or lowered in the unit aggregation process or over the unit aggregation processes. Evaluate if there is a tendency and adjust the agitation power in the unit agglomeration process or unit agglomeration processes where a constant or descending trend is identified.

16 to 19 show the results of the floc grown in each unit flocculation unit of the actual water treatment plant to which the apparatus according to the present invention is collected through a light scattering analyzer.

Wherein the coagulation step is carried out in a continuous process via a plurality of unit coagulation processes, the light scattering analysis value (RMS) or the light scattering analysis ratio remains constant in the unit coagulation process or over the unit coagulation processes If there is a tendency to hereinafter (hereinafter referred to as " maintenance tendency " for convenience) (see FIG. 16), the stirring power is adjusted to drive the retention tendency to a tendency to rise.

Looking at Figure 16, it can be seen that the stirring power has been kept constant throughout the unit agglomeration processes, such as 50s ^-1 , 50s ^-1 , 50s ^-1 , which is generally considered in view of reducing the stirring power If the power is kept constant and is evaluated as the holding tendency, it means that the stirring power is excessively input and the floc is destroyed, so that the stirring power is not increased in the unit flocculation process or the unit flocculation processes in which the holding tendency is known. Should be lowered.

However, if the agitation tendency is maintained as in FIG. 16, but unlike FIG. 16, the agitation power has gradually dropped over the unit flocculation processes (eg, 50s ^-1 , 20s ^-1 , 5s ^-1 ), the agitation power is small and floc. Since this means that it is not formed and settles, the stirring power must be increased in the unit aggregation process or the unit aggregation processes in which the retention tendency is identified.

On the other hand, when the aggregation step is performed in a continuous process through a plurality of unit aggregation processes, the light scattering analysis value (RMS) or the light scattering analysis ratio (ratio) is lowered in the unit aggregation process or across the unit aggregation processes If there is a trend (hereinafter referred to as "downward trend" for convenience) (see Figures 17 and 18), the agitation power is adjusted to drive the downtrend to an upward trend.

Referring to FIG. 17, the second unit agglomeration process, that is, the tendency to descend from the flocculation 2 site, and the FIG. 18, the third unit agglomeration process, that is, the tendency to descend from the flocculation site 3 is shown.

In such unit aggregation processes (aggregation 2 and 3 in FIG. 17) or the unit aggregation process (aggregation 3 in FIG. 18) showing such a tendency to descend, the stirring power should be adjusted so that the tendency of the descending tends to be upward. .

Here too, it is of course necessary to lower the stirring power if the stirring power has been kept constant throughout the unit processes.

However, as described above, in general, the stirring power is gradually lowered. At this time, it is more advantageous to grasp the quality of the precipitated water together to induce the downward tendency to the upward trend through controlling the stirring power.

That is, the stirring power has been lowered over the unit flocculation processes, and if the tendency to fall is found, the stirring power is not unconditionally increased, but the precipitation water quality of the precipitated water treated through the flocculation process is considered. In other words, if the precipitation turbidity needs to be lowered (if the precipitation quality is not good), this means that the stirring power is large and the floc is broken, thereby lowering the stirring power in the unit flocculation process or the unit flocculation processes. However, if there is no need to lower the precipitation turbidity (if the settling water quality is good), then the stirring power is small and the floc can be thought of as settling, which in this case increases the stirring power in the unit flocculation process or in the unit flocculation processes.

In order to determine whether it is necessary to lower the precipitation turbidity, it is preferable to determine that it is not necessary to lower the precipitation turbidity when the value is determined between 1 NTU and 1.5 NTU. Do. This is because, in the case of 1 NTU or less, it is generally evaluated that the settling water quality is good, but in the actual process, even if the settling turbidity reaches 1.5 NTU, the settling water quality may be evaluated as good in relation to the stirring power control.

19 is an example showing good results of floc growth by adjusting the stirring power.

According to the present invention, the existing mechanical rapid mixing device and the horizontal paddle stirring type flocculating device which have been used in the conventional water purification process have been improved to the instantaneous mixing device and the vertical axis flocculating device in the pipe, and the chemical mixing which is important for the operation of the water treatment process And require relatively low power requirements for flocculation, and further, improved chemical admixture to improve removal rates of colloidal particles, natural organic matter (NOM) and disinfection by-product precursors in raw water, and to evaluate existing drug injection and flocculation processes. By improving, the reliability of water treatment and the ease of maintenance can be improved.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the appended claims will cover such modifications and variations as fall within the spirit of the invention.

Claims (32)

An instantaneous mixing device in which raw water is introduced from the impingement well, agglomerated chemical is injected, and instantaneous mixing of the flocculating chemical and the incoming raw water is performed; A flocculating drug injecting and controlling device for injecting a flocculating drug into the instantaneous admixture and controlling the injection thereof; A flocculating device in which mixed water flows from the blending device and agglomeration is performed in the mixed water by stirring the stirring device; And And a coagulation measurement and regulating device for measuring a coagulation state in the coagulation apparatus and controlling a coagulation process. The flocculation measurement and control device includes a light scattering analysis device for measuring a growth state of the flocculation floc by light scattering analysis and evaluating a change in light scattering analysis value (RMS) or light scattering analysis ratio; And the light scattering analysis value RMS or the light scattering analysis ratio when the light scattering analysis value RMS or the light scattering analysis ratio tends to fall or remain constant. And a stirring power adjusting device for adjusting the stirring power of the stirring device. The method of claim 1, The instantaneous admixture measures the flow rate of any one or both of the raw water or the pressurized water, and in response to the measured value, is discharged from the flow of raw water and pressurized again into the raw water and sprayed with the flocculating chemicals. And a regulating device for adjusting the instantaneous mixing strength by adjusting the flow rate of the pressure water. According to claim 1, wherein the instantaneous mixing device, Raw water pipe; A pressure water line flowing out of one side of the raw water pipe and then flowing back into the raw water pipe; A vertical pipe connected to the pressure water line and vertically installed in the raw water pipe; A pressure water and agglomeration chemical injection pipe connected to the vertical pipe, in which pressure water flows and agglomeration chemicals flow so as not to mix with the pressure water, and a deflector is provided at an end thereof; A flow meter installed in the pressure water line; A variable speed pump installed in the pressure water line; And And a controller connected to each of the flowmeter and the variable speed pump and controlling the pumping speed of the variable speed pump in response to the pressure water flow rate of the pressure water line. Device. According to claim 1, wherein the flocculation drug injection and control device, Aggregate drug injection device for injecting coagulation drug into the raw water; A flow current measuring device for measuring a flow current of the mixed water; And And a coagulation drug injection control device configured to adjust the coagulation drug injection so that the flow current value has a set value or is in a set range in response to the measured flow current value. According to claim 1, wherein the flocculation drug injection and control device, A first pH meter for measuring the pH of the raw water; A second pH meter for measuring pH of the mixed water; And And an alkali adjuvant injector for injecting an alkali adjuvant into the raw water such that the pH value of the first pH meter and the pH value of the second pH meter are each within a set range or have a set value. . According to claim 1, wherein the flocculation drug injection and control device, A first pH meter for measuring the pH of the raw water; A second pH meter for measuring pH of the mixed water; An alkali adjuvant injector for injecting an alkali adjuvant into the raw water; A flocculating chemical injector for injecting flocculating chemical into the raw water; A flow current meter for measuring the flow current of the mixed water; The first pH meter, the second pH meter, the flow current meter, the coagulant injector, and the alkali auxiliary injector are respectively connected in a wired or wireless manner, and the flow current in real time corresponding to the measured flow current value. Adjust the flocculation chemical injection so that the value is within the set range or has a set value, and the pH value of the raw water and the pH value of the mixed water are adjusted in real time corresponding to the measured pH value of the raw water and the pH value of the mixed water. And a microprocessor for controlling the injection of the alkali adjuvant to be within a set range or to have a set value, respectively. The method of claim 6, wherein the microprocessor, When the absolute value or relative reference value of the measured flow current value is 0, the flocculation drug injection is continued as before, and when the absolute value or relative reference value of the measured flow current value is less than 0, the flocculation drug injection is performed. And increase agglomeration chemical injection when the absolute value or relative reference value of the measured flow current value is greater than zero. The method of claim 6, wherein the microprocessor, And controlling the injection of the alkali adjuvant so that the pH value of the raw water is less than 8.0 and the pH value of the mixed water is within a range of 6.5 or more. The method of claim 8, And a pH value of the raw water to be less than 7.5. The method according to any one of claims 5 to 9, And said alkali adjuvant is sodium hydroxide. The stirring device of the flocculating device according to claim 1, Driver; A vertical drive shaft connected to the driver; And an impeller connected to the vertical drive shaft and having a fallopian tube shape having a diameter gradually extending from an upper part to a lower part, wherein an impeller having a spiral transmission feather disposed radially on the fallopian tube. The method of claim 1, The agglomeration apparatus is composed of a plurality of unit agglomeration paper continuously, The agglomeration measuring and regulating device is characterized in that the unit agglomeration is such that the light scattering analysis value (RMS) or the light scattering analysis ratio is in a holding tendency to remain constant in the unit agglomerate or over the unit agglomerates. If the stirring power was constant over the branches, the stirring power at the unit agglomeration paper or the unit agglomeration papers showing the holding tendency was lowered, or if the agitation power had been reduced over the unit agglomeration papers, the holding tendency was reduced. The water treatment apparatus which raises the stirring power in the said unit aggregation paper or said unit aggregation paper which is seen. The method of claim 1, The flocculation measuring and regulating device is a water purification apparatus characterized in that connected to the precipitation turbidity measuring device for measuring the precipitation turbidity of the treated sediment from the flocculating device to reflect the precipitation turbidity measurement results when adjusting the flocculation process. The method of claim 13, The agglomeration apparatus is composed of a plurality of unit agglomeration paper continuously, The flocculation measuring and regulating device is characterized in that the light scattering analysis value (RMS) or the light scattering analysis ratio is inclined to fall from or across the unit flocculation papers, and stirs across the unit flocculation papers. When the power has been reduced, if it is necessary to lower the precipitation turbidity input from the precipitation turbidity measuring device, lower the stirring power in the unit agglomeration paper or the unit agglomeration papers that tend to fall, or lower the precipitation turbidity. If there is no need to increase the stirring power in the unit agglomeration paper or the unit agglomeration paper showing the tendency to fall, characterized in that the water treatment apparatus. The method of claim 14, If the precipitation turbidity is less than one value selected from 1 to 1.5 NTU, it is determined that the precipitation turbidity need not be lowered, and if higher than the value, it is determined that the precipitation turbidity needs to be reduced. The method of claim 1, And the light scattering analysis value (RMS) or the tendency of the light scattering analysis ratio to be adjusted in a state in which the flocculation chemical injection amount is controlled to improve floc growth. The method of claim 16, The water treatment apparatus characterized by evaluating the tendency of the light scattering analysis value (RMS) or the light scattering analysis ratio (ratio) in parallel with the flocculation chemical injection and alkali assistant injection. An instantaneous mixing step (S1) of introducing raw water from the impingement well, injecting flocculating chemicals, and performing instantaneous mixing of the flocculating chemicals and the incoming raw water; Aggregate drug injection control step (S2) for controlling the injection of the flocculation drug; An agglomeration step (S3) for carrying out agglomeration through mixed water; And By measuring the aggregation state and controlling the aggregation process in response to the measured result, by measuring the growth state of the flocculation floc by light scattering analysis, evaluating the tendency of light scattering analysis value (RMS) or light scattering analysis ratio (ratio) When the light scattering analysis value RMS or the light scattering analysis ratio tends to fall or remain constant, the light scattering analysis value RMS or the light scattering analysis ratio tends to increase. And a coagulation measurement and adjustment step (S4) for controlling the stirring power during coagulation. The method of claim 18, In the step S1, the flow rate of any one or two of the raw water or the pressure water is measured, and in response to the measured value, the pressure is discharged from the flow of the raw water and pressurized to flow back into the raw water and sprayed with the flocculating chemicals. The instantaneous mixing strength is adjusted by adjusting the flow rate of water. The method of claim 18, In the step S2, the water treatment method characterized in that for measuring the flow current of the mixed water and controlling the injection of the flocculating chemicals so that the flow current value has a set value or in a set range corresponding to the measured flow current value. The method of claim 18, In step S2, the pH value of the raw water is measured, the pH value of the mixed water is measured, and the pH of the raw water and the pH value of the mixed water are each injected with an alkali adjuvant to be within or within the set range. Integer processing method characterized in that it further comprises. The method of claim 18, wherein in the step S2, The pH value of the raw water is measured, the pH value of the mixed water is measured, and the pH value of the raw water and the pH value of the mixed water are respectively within a set range or have a set value in response to the measured pH values in real time. Injecting an alkali adjuvant into raw water (S2-1); And Measuring a flow current of the mixed water and injecting the flocculating agent injecting the flocculant so that the flow current value is within a set range or has a set value in real time corresponding to the measured flow current value (S2-2) An integer treatment method comprising a. The method of claim 22, In the step S2-1, so that the pH value of the raw water is less than 8.0, and the pH value of the mixed water is controlled to the injection of the alkali adjuvant so as to be in the range of 6.5 or more. The method of claim 23, The pH value of the raw water is characterized in that less than 7.5. The method of claim 22, In step S2-2, when the absolute value or relative reference value of the measured flow current value is 0, the flocculation drug injection is continued as before, and the absolute value or relative reference value of the measured flow current value is smaller than 0. Increasing the flocculating chemical injection when the flocculating chemical injection is increased, and reducing the flocculating chemical injection when the absolute value or the relative reference value of the measured flow current value is greater than zero. The method of claim 22, wherein in the step S2, When the pH value of the raw water is less than 7.5, continuing the injection of the alkali adjuvant as before, and reducing the injection of the alkali adjuvant when the pH value of the raw water is 7.5 or more (S2-1a); After the step S2-1a, when the absolute value or the relative reference value of the measured flow current value is 0, the flocculation drug injection is continued as before, and the absolute value or the relative reference value of the measured flow current value is smaller than 0. Increasing the flocculation drug injection in the case of reducing the flocculation drug injection when the absolute value or the relative reference value of the measured flow current value is greater than zero (S2-2); And After the step S2-2, if the pH value of the mixed water is less than 6.5 to increase the injection of the alkali adjuvant and if the pH value of the mixed water is greater than 6.5 to continue the injection of the alkali adjuvant as before (S2-1b) An integer treatment method comprising: a. 27. The method of any of claims 21 to 26, And said alkali adjuvant is sodium hydroxide. The method of claim 18, The aggregation step is to be carried out continuously through a plurality of unit aggregation process, When the light scattering analysis value (RMS) or the light scattering analysis ratio is in the holding tendency to remain constant in the unit flocculation process or over the unit flocculation processes, the stirring power is increased over the unit flocculation processes. If constant, the agitation power in the unit agglomeration process or the unit agglomeration processes showing the holding tendency was lowered, or the unit agglomeration showing the holding tendency, if the agitation power had been reduced over the unit agglomeration processes. A water treatment method characterized by increasing the stirring power in the process or corresponding unit flocculation processes. The method of claim 18, The aggregation step is to be carried out continuously through a plurality of unit aggregation process, The light scattering analysis value (RMS) or the light scattering analysis ratio (ratio) tends to fall in the unit agglomeration process or across the unit agglomeration processes, and stirring power has been reduced over the unit agglomeration processes For example, if the precipitation turbidity of the precipitated water treated through the coagulation process needs to be lowered, the stirring power in the unit coagulation process or the unit coagulation processes showing the downward tendency is lowered, or the precipitation of the precipitated water treated through the coagulation process is reduced. If it is not necessary to lower the turbidity, the water treatment method characterized in that the stirring power in the unit flocculation process or the unit flocculation process showing the tendency to fall. The method of claim 29, If the precipitation turbidity is less than one value selected from 1 to 1.5 NTU it is determined that the precipitation turbidity need not be lowered, and if higher than the value it is determined that the precipitation turbidity characterized in that it is necessary to lower. The method of claim 18, And the light scattering analysis value (RMS) or the light scattering analysis ratio (ratio) in a state in which the flocculant injection amount is adjusted to improve floc growth. The method of claim 31, wherein Evaluating the tendency of the light scattering analysis value (RMS) or the light scattering analysis ratio (Ratio) while the flocculating drug injection and the alkali adjuvant in parallel.

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