KR20010038085A - An In-site River Purifying System - Google Patents

Abstract

PURPOSE: In-situ purifying system of stream water is provided to eliminate factors causing eutrophication such as organics, nitrogen, and phosphate by using Dissolved Air Floatation (DAF) method along with the injection of coagulants in advance. CONSTITUTION: As stream water flows into the in-situ purifying system by a guide plate, coagulants stored in a chemical tank (20) are injected into stream water through a plurality of injectors (22). Also, a plurality of compressed water injectors (23) or agitators is installed to accelerate the mixing efficiency of suspended solids with coagulants. At a predetermined distance down the stream, a plurality of injectors (33) for supplying air-dissolved compressed water is installed. By injecting air-dissolved compressed water into stream water, fine air bubbles are generated. Floc which is formed by the chemical reaction of suspended solids with coagulants rises up to water surface by the fine air bubbles. This floated scum is collected by a guide float (13) and a scum scraper (40), and finally dehydrated. In this system, a plurality of baffles is perpendicularly installed to stream current for stable flocculation.

Description

In-site River Purifying System

The present invention relates to a water purification device of a river or river, and more specifically, to administering a flocculant in a site (in-site), admixing, flocculating, and using a dissolved air flotation method (DAF) to contaminate river water. It relates to a device that can remove the.

Water deterioration due to nutrients such as nitrogen and phosphorus contained in fertilizers, livestock wastewater, domestic sewage, and factory wastewater is increasing. As a result, green algae and red tide occur in rivers, lakes, and oceans, destroying ecosystems. Water eutrophicated by nutrients in river water and wastewater causes algae to thrive. When the algae thrives on the surface of the water, it prevents the light from penetrating, thus preventing the photosynthesis of aquatic organisms and lowering the oxygen dissolution rate in the water, thus losing the self-cleaning ability of the water.

Green algae and red algae generated by eutrophication can shut off the oxygen supply to water and kill fish and fish that live in the water. In addition, when the red tide phenomenon occurs in the water supply source, algae taste problem occurs due to algae water purification, and excessive chlorine disinfection, trihalomethane (THM) can be formed. In Korea, hundreds of billions of won are incurred every year by the occurrence of annual green and red tide, which are annual events in spring and autumn. In addition to the removal of algae, water purification measures for nonpoint sources are urgently needed.

In order to fundamentally improve the water quality of the stream, there is a method of purifying the water quality from the pollutant discharge source or transferring the waste water to the sewage treatment plant for treatment. However, the installation of a water purification system for many pollutant sources or the transfer to a sewage treatment plant requires a huge budget. In addition, in the case of point pollutants, the problem is relatively small, but in the case of nonpoint pollutants, there is no special treatment for water treatment.

Patent Publication No. 93-23280 relates to an apparatus for purifying river water using a charcoal layer and a gravel layer, and a technique related to a biofilm river purification apparatus using waste concrete or waste tire is disclosed in Korean Patent Publication Nos. 97-20976 and 97-. 20977. In addition, Japanese Patent Application Laid-Open No. 99-24172 describes a method for purifying a river using a microbial contact material. Further, Japanese Patent Laid-Open Nos. 95-26882 and 95-24975 describe a device for supplying oxygen to a stream to preserve the ecosystem of the stream. However, in streams with high flow rates or in rivers with high yields, the filtration, biooxidation or aeration purification methods are fundamentally limited.

Patent Publication No. 99-24236 relates to a water purification system using a water channel, and describes a system for installing a water channel on one side of a lake to inhale the raw water of the lake with an absorption pipe, moving it to the water channel, and generating and purifying ultra-miniature bubbles. have. However, this system uses only ultra-micro-foams without any flocculation flocculation process, and thus it is difficult to sufficiently float fine suspended matters or contaminants. Since the raw water must be sucked into the absorption pipe, power is also consumed. In addition, this system has a problem that the raw water has to be drawn into a small water channel, and thus it is not sufficient to process the entire water system to be treated, and there is a problem in that the purification effect is insignificant when a sudden change in the water quality or an increase in the water quality.

An object of the present invention is to overcome the problems of the prior art described above, to provide a water purification device that can be easily installed without the need for large-scale civil engineering work.

It is also an object of the present invention to provide an apparatus for water purification that is more efficient than the purification method using physical filtration or microorganism media.

In addition, an object of the present invention is to provide a water purification apparatus that can cope with a sudden change in sewage water quality.

1 is a conceptual diagram showing an embodiment of the device of the present invention.

2 is a conceptual diagram showing another embodiment of the device of the present invention.

Brief description of the reference numbers

12: river water guide plate 13: guide float

20: chemical tank 21: chemical pump

22: chemical injector 23: high pressure water injector

30: pressurized pump 31: compressor

32: pressurized tank 33: pressurized water injection device

40: scum collection device 41: dewatering device

In order to achieve the above object, the present invention is a river (hereinafter referred to as "river" is used as a generic term for streams and streams with rivers, etc.) between both eyes to be located in water below 1-5m from the bottom or the water surface. Install an underwater structure that crosses both eyes and is perpendicular to the flow direction, and install a chemical injection device for injecting agglutinating drugs on the upstream side of the structure, and an agitator or high pressure water injection device for agitating the agglomerated drug and the water to be treated, and downstream. Towards the side, install a pressurized water jet containing dissolved air. In addition, a guide float is installed downstream of the pressurized water injection device, and a scum collection device and a dewatering device are installed to extend with the guide float.

The apparatus of the present invention will be described in more detail. That is, the apparatus of the present invention is a chemical tank (20) for storing agglomerated drugs, a chemical pump (21) for supplying agglomerated drugs to the chemical injection device, a pressurized pump for supplying a portion of the treated water or treated water to the pressurized tank ( 30), a compressor 31 for supplying compressed air to the pressurized tank, a pressurized tank 32 for mixing and dissolving water supplied by the pressurized pump and compressed air by the compressor and storing pressurized water containing dissolved air. ), A chemical spraying device 22 for injecting a flocculant into the water to be treated containing suspended solids such as algae, a stirring device or a high pressure water injector 23 for mixing the flocculant with the suspended solids, pressurized air A scum collecting device 40 such as a pressurized water injector 33 for discharging water, a guide float 13 for preventing the spread of scum on the water surface, a scum suction device for sucking scum or a scraper, and a scum containing water Dehydrated and suspended solids The removal process may consists of a dewatering device (41) for the reduction of the stream.

The configuration and operation of the apparatus of the present invention will be described in more detail with reference to the drawings.

Place the power and chemical tanks, chemical pumps, pressurized tanks, pressurized pumps and compressors on the surface of the bottom of the riverbed or submerged structures, and install underwater structures, preferably steel pipes, that can withstand the flow of water between the two eyes. . The structure is equipped with chemical injection device, high pressure water injection device or stirring device, and pressurized water injection device. A guide float is installed downstream, and a scum collection device and a dewatering device are installed to extend from the guide float.

The suspended solids in water react with the flocculant supplied by the flocculant injector to form flocs. Injection of the flocculant is supplied from the chemical tank 20 using the chemical pump 21 in the chemical injector 22. The floc formed by the flocculant spray is attached by the microbubbles of the dissolved air and floats to the surface of the water system. That is, the water to be treated or a part of the treated water is injected into the pressure tank 32 through the pressure pump 30, and then the water is pressurized to a pressure of 3 atm or higher, preferably 4 to 7 atm using the compressor 31. To sufficiently saturate the dissolved air in water. Thereafter, the pressurized water injection device 33 supplies the pressurized water saturated with the dissolved air to generate fine air droplets. In other words, the air dissolved in the pressurized water is rapidly released under atmospheric pressure to form fine air bubbles to float flocs, suspended matter, algae, etc. in the water and float above the water surface. Scum injured on the surface (hereinafter referred to as "scum" is used to collectively refer to algae, suspended matter, contaminants, etc.) injured in the water is collected by the scum collection device 40 is dewatering device 41 By dehydration).

The high pressure water injector 23 serves to smoothly mix the suspended solids in the water to be treated with the flocculant. The stirring device may be used instead of the high pressure water injector, or the coagulant and the high pressure water may be simultaneously sprayed in the chemical injection device. The high pressure water injector injects the pressurized water in which the air supplied from the pressurized tank is dissolved or injects the treated water at high pressure by a compressor or a separate submersible pump.

The high pressure water injector may exist separately from the chemical injector, but may simultaneously inject the high pressure water and the coagulant through a single injector.

As such, the treated water rapidly admixed with the flocculant by the pressure of the high pressure water or the stirring device naturally stirs and grows the floc according to the flow of the river water. Alternatively, additionally, a plurality of baffles may be installed at right angles to the flow of the stream so that flocs can grow between the water passing through the baffles.

The floc formed by the flocculant and grown by the flow of water is attached to the surface of the fine air bubbles of about 10 to 100 µm generated by the pressurized water injected from the pressurized water injector 33 to float above the water surface. The pressurized water injector is located downstream of the chemical injector, agitator, or high pressure water injector, and one or more injectors may be installed, and may be moved up and down in accordance with the flow rate of the stream. In addition, when the amount of suspended matter or algae to be treated is large, it is possible to increase the treatment efficiency by operating a plurality of pressurized water injection device.

Scum that floats to the surface of the water to be treated is collected by a guide float on the downstream side according to the flow of the stream, collected by the scum collection device, and then solid-liquid separated by the dehydration device. Scum collection and dewatering devices may be installed on the bottom, or on top of small ships, barges, underwater structures or buoys fixed on the bottom. The treated water is discharged back to the treated part, that is, the stream.

In the apparatus of the present invention, the water quality sensor and the chemical injection amount control device may be added to purify the water quality more effectively.

The chemical injection quantity control device determines the injection amount of the flocculant by measuring the water quality of the inflow water containing flocculants such as algae and colloidal particles and nutrients such as nitrogen and phosphorus or the water quality of the flocculant treated water with a water quality sensor. Do this. The chemical injection control device used the turbidity, alkalinity, water temperature and pH of the influent measured by the water quality sensor as independent variables, and the flocculation chemical injection amount as the dependent variable.

Turbidity and alkalinity of the influent have a positive correlation with the flocculant injection amount. That is, when turbidity and alkalinity are high, the flocculant injection amount will increase. In contrast, the water temperature and pH of the influent have a negative correlation with the coagulant injection volume. In other words, when the water temperature of the influent water is low or the pH is low, the amount of flocculant injected increases, and when the water temperature is high or the pH is high, the amount of flocculant injected is small.

As another example of the drug injection amount control device, the zeta potential or stream current of the flocculated chemical treatment water may be measured as an independent variable, and the injection amount of the coagulated chemical, which is a dependent variable, may be determined according to the change of the independent variable.

As another example, an optimal drug injection amount may be obtained by combining a feedforward control method for controlling the drug injection amount according to the quality of the inflow water, and a feedback control method for determining the drug injection amount according to the zeta potential or stream current of the flocculated drug treated water. You can decide.

The chemical pump can prevent the deterioration of the coagulation efficiency due to the excessive or excessive coagulant by injecting an optimum amount of a chemical such as an organic coagulant or an inorganic coagulant into the rapid mixing tank according to the chemical injection amount determined by the chemical injection amount control device.

In addition, in the apparatus of the present invention in the process of handling the suspended solids attached to the surface of the micro-bubbles floating on the water surface and removed, the present invention measures the density of the suspended solids, the drive speed of the scraper to collect scum when the density is high In the case of increasing the density of the suspended solids and lowering the density of the suspended solids, a scraper control device capable of treating the suspended solids in the concentrated state may be added.

The scum treatment apparatus generally adopted in the conventional pressure flotation method operates at a constant driving speed regardless of the concentration or amount of scum. Thus, if a large amount of scum is formed, it is not possible to perform a complete treatment. If the concentration of scum is low, the treatment is performed in a state containing a large amount of water.

Thus, in the present invention, as an example of the scum recovery device, a suspended material density sensor for measuring the concentration of scum that has risen to the upper layer, and a scraper control device and a scraper having the measured value as an independent variable and the driving speed of the scraper as a dependent variable are adopted. It was. The scraper control device of the present invention is associated with a scraper, and can appropriately cope with a situation change such as a large amount of algae caused by a change in water temperature and a large inflow of suspended substances due to heavy rain. In addition, when the amount of floating material is small, the load of the dewatering device is reduced by lowering the driving speed of the scraper.

As another embodiment of the present invention, a device and method to which the above-described device is applied will be described.

When the flow rate of the river water is large, a water purification apparatus using a mixing, flocculation, and dissolved air flotation method by flocculant in the same way as the apparatus in the bypass channel by inducing part of the river water to the side of the river.

As shown in Figure 2, the river water guide plate is fixed to the bottom. The river water guide plate extends from the bottom to the surface. Thus, part of the river water is directed laterally. On the side of the river, a simple dredging operation forms a bypass channel.

The stream water guided to the bypass channel by the river water guide plate is mixed with the coagulant of the chemical tank by spraying it with the chemical injection nozzle through the chemical pump. Rapid mixing of river water and flocculant uses high pressure water or agitation device. Thus, flocs are formed, and the rapidly mixed water is stirred slowly by the flow of water or by a plurality of intersecting baffles so that the flocs grow. The pressurized water produced by the compressor and the pressurized pump is injected into the water by the pressurized water injector from the pressurized tank. The air dissolved in the pressurized water is rapidly released under atmospheric pressure to form fine air bubbles to remove pollutants in the water. Attach and float above the surface of the water. The scum that floats to the surface is collected by the guide float, collected by the guide float and the extended scum collector, and dewatered by the dehydrator before processing.

If the flow rate increases due to heavy rain, etc., and a large amount of pollutants to be treated, install a bypass channel on the right side of the river, install the device of the above application, and install the bypass channel on the left side of the stream on the downstream side By installing a plurality of devices in such a way to improve the water quality of the stream efficiently.

The present invention can effectively purify rivers or large-scale lake water and oceans by removing floating substances and eutrophication agents such as nitrogen and phosphorus present in river water flowing into rivers or lakes.

The present invention can also greatly reduce the load of the water purification plant because it does not require high water purification by purifying the water quality of the lake used as a water source.

In addition, the device of the present invention can be processed in-situ can economically purify the river water.

In addition, the present invention is to reduce the water treatment efficiency by appropriately adjusting the injection amount of the flocculant drug and spraying the pressurized water according to the change in the water quality of the sewage due to the change of the water temperature and the change of the water quality such as the mass inflow of suspended solids by the heavy rain or It is possible to overcome the disadvantages of the prior art, in which water treatment was not possible.

Claims (5)

Chemical tanks for storing flocculated chemicals, chemical pumps for supplying flocculated chemicals to the chemical injection device, pressurized pumps for supplying treated water or treated water to pressurized tanks, compressors for supplying compressed air to the pressurized tanks, and pressurized pumps. Place a pressurized tank for storing pressurized water in which the supplied water and the compressed air by the compressor are mixed and dissolved, and placed on the upper surface of the upper surface of the riverbed or the underwater structure, As an underwater structure, a chemical injector for injecting a flocculant into the water to be treated, a stirring device or a high pressure water injector for mixing the flocculant and suspended solids, and a pressurized water injector for ejecting the pressurized water in which air is dissolved, To prevent the spread of scum to the downstream side, install a guide float to collect the scum, A scum collection device and a dewatering device are installed in connection with the guide float current location purification device of the river water. The method of claim 1, On the upstream side is extended from the riverbed to the surface of the river and additionally installed river water guide plate to guide the river water to one side, install a bypass channel to the side of the river, Install the chemical injector, high pressure water injector or stirring device and pressurized water injector in the bypass passage, To prevent the spread of scum to the downstream side, install a guide float to collect the scum, Scum collection device, dewatering device is installed in connection with the guide float, the current position purification device of the river water, characterized in that configured. The method according to claim 1 or 2, Current location purification apparatus for river water, characterized in that a plurality of baffles are installed between the stirring device or the high pressure water injection device and the pressurized water injection device. According to claim 1 or claim 2, Water quality detection sensor for detecting the change in the water quality of the inflow water, the current position of the river water, characterized in that for adding the chemical injection amount control device for controlling the amount of coagulant injection according to the water quality detected by the sensor Purifier. According to claim 1 or claim 2, The scum collection device is a suspended solids density sensor for detecting the solids content of the suspended suspended solids, scraper control device for adjusting the scraper driving speed according to the solids content and the collected scum collected Current position purification apparatus of river water, characterized in that consisting of a scraper.