JP2006159027A - Sludge treatment apparatus and sludge treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sludge treatment apparatus and sludge treatment method which can safely and efficiently treat sludge at the site, and further improves the environment by zeolite generated by the sludge treatment. <P>SOLUTION: The sludge treatment apparatus 1 has a floating body 10 that floats on the water surface. The floating body 10 carries a sludge collecting device 20 that collects the sludge from a sludge layer S in the water bottom, a dehydrator 21 that dehydrates the collected sludge, a zeolite production device 22 that produces zeolite powder by using the dehydrated sludge as a raw material, a granulator 23 that converts the zeolite powder into a molded material, and a spray device 24 that sprays the molded zeolite onto the water bottom. Water separated from the sludge is, together with water taken from a stagnant water region W2 by a water-intake device 27, oxygen enriched in a wastewater treatment device 25 to be returned to the stagnant water region W2 by a return device 26. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus and method for treating sludge in water.

  The sludge generated by human economic activities has become a problem in various places as a cause of environmental pollution. Therefore, technological development for removing sludge, making it harmless, and producing useful substances from sludge has been actively conducted.

  In general, sludge is treated as industrial waste by transporting dredged sludge to land. However, this method has an excessive transportation cost for transporting dredged sludge to a land processing plant. In addition, since the land treatment plant is stationary, the operation rate tends to be low when the purification point is far away, and it takes time to depreciate the equipment, and it is also necessary to provide a sludge reservoir on land. In addition, sludge placed in the reservoir causes secondary pollution such as offensive odor, and various problems such as sewage exuding from sludge must be properly treated and returned to the water system.

  This led to the idea of treating sludge not on land as industrial waste, but on the spot. Examples thereof can be seen in Patent Documents 1-3.

  In Patent Document 1, the bottom of the muddy water is pumped up to a work ship floating in the water area to be treated, a powdery inorganic flocculant is added to the muddy water, mixed, and this muddy water is directly returned to the water area to be treated. A purification method is disclosed.

  Patent Document 2 discloses a sludge treatment ship that desalinates dredged sludge, removes heavy metals, and then dehydrates and dries to recycle.

Patent Document 3 discloses a disposal method for dredged mud that mixes and solidifies a solidifying agent in dredged mud, and then cures and solidifies in a curing tank, and throws the solidified mud after curing into the seabed. Yes.
Japanese Patent Laying-Open No. 2003-181465 (page 2 to page 3, FIG. 1) Japanese Patent Laid-Open No. 10-273094 (2nd page to 4th page, FIGS. 1 to 6) Japanese Patent Laid-Open No. 8-270002 (page 3 to page 4, FIGS. 1 to 5)

  If sludge is processed on the water like what was indicated by the above-mentioned patent documents, since it is not necessary to provide a fixed facility on land, there is no restriction on the place of activity. By transporting the treatment ship to places where sludge tends to accumulate, such as aquaculture sites and estuaries of cultivated fishery such as seaweed, oysters, and fish, and processing sludge on the spot, bad odors and noise will not be a problem, and processing costs will also be Can be cheap. However, the conventional processing method has the following problems.

  In the construction method disclosed in Patent Document 1, the muddy water mixed with an inorganic flocculant is returned to the water as it is. Solids such as sediment particles and suspended solids suspended in the muddy water adsorb to each other, flocking and starting to settle immediately, but it is difficult to say that the floc is sufficiently large. It is difficult to prevent being swept away. In other words, it can be considered that mud water is diffused by water flow and pollutes the water itself, and that mud covers the bottom of the water over a wide area and poses a threat to aquatic life. In addition, mud is only flocked, and no harmful components are contained, so it cannot be said that the danger of the harmful components dissolving in water could be eliminated.

  In the sludge treatment ship disclosed in Patent Document 2, desalting is performed, heavy metals are removed, and the dehydrated and dried sludge is stored in a storage tank. This sludge will be recycled later, but until then it must be stored on board. For this reason, there is a limit to the sludge processing capacity, and it is not suitable for the purpose of processing a large amount of sludge without taking a rest.

  In the disposal method of dredged mud disclosed in Patent Document 3, the cured mud is thrown into the seabed. Until the curing period elapses, the mud must be kept on board and the mud rotation rate is poor. Moreover, since the harmful components in the mud are not contained, it cannot be said that the risk of the harmful components dissolving in the water could be excluded.

  The present invention has been made in view of the above points, and provides a sludge treatment apparatus and a sludge treatment method that can treat sludge safely and efficiently on the spot and that the sludge treatment further improves the environment. Objective.

  (1) In order to achieve the above object, the sludge treatment apparatus of the present invention includes a floating body that floats on the water surface. The floating body includes a sludge collecting apparatus that collects sludge from the bottom of the water, and a dehydrator that dehydrates the collected sludge. And a zeolite production apparatus for producing zeolite powder using dehydrated sludge as a raw material, a granulating apparatus for forming the zeolite powder into a molded product, and a spreading device for distributing the molded product on the bottom of the water. Yes.

  According to this configuration, sludge is processed by a floating body that floats on the water surface, so sludge can be processed at a low cost at the place where the sludge is present. Since the chemical activity of zeolite has the ability to purify water, the zeolite molding is effective in improving the environment centering on water purification and removal of harmful substances generated from sludge at the bottom of the water. Moreover, since the zeolite molded product may be distributed in the water as soon as it is produced, it is not necessary to provide a storage facility in the floating body, and it is possible to continue to produce the molded product at full operation without worrying about the storage capacity of the storage facility. Can process sludge very efficiently.

  If the top of the sludge layer is covered with the zeolite molding, the environment of the processing target section can be improved without treating the sludge layer to the bottom. In addition, the zeolite moldings spread on the bottom of the water serve as a medium for aquatic organisms, which leads to an abundance of fishery resources.

  (2) Further, according to the present invention, in the sludge treatment apparatus having the above-described configuration, a wastewater treatment apparatus for oxygen-enriching water separated from the sludge and a reflux apparatus for returning the water after the oxygen-enrichment treatment to water are loaded. It is characterized by being.

  According to this configuration, the water separated from sludge is not returned to the water as it is, but is returned after being oxygen-enriched, so that the activities of the microorganisms in the water are activated, and the COD (chemical oxygen demand) and BOD (biochemical oxygen) in the area are activated. demand) is improved.

  (3) Further, according to the present invention, in the sludge treatment apparatus configured as described above, the waste water treatment apparatus performs oxygen enrichment after adding water taken from a staying water area in water to water separated from sludge, The water after the enrichment treatment is returned to the staying water area by the reflux device.

  According to this configuration, the water in the staying water area is circulated simultaneously with the sludge treatment, and this is not a simple circulation, and the water subjected to the oxygen enrichment process is returned to the staying water area. Thereby, the activity of the aquatic microorganisms in the staying water area is activated, and COD and BOD in the staying water area are improved. Generally, the water in the staying water area has a high COD and a high BOD, and thus improving the water quality in this way is extremely effective for environmental conservation.

  (4) Moreover, the present invention is characterized in that in the sludge treatment apparatus having the above-described configuration, a support plant that supplies power necessary for sludge treatment is loaded on the floating body.

  According to this configuration, it is not necessary to draw power from the outside, and self-contained sludge processing becomes possible. Therefore, sludge treatment activity can be performed at any place. Moreover, it becomes possible to give the floating body navigation ability by the power.

(5) Further, the present invention is a sludge treatment method using the sludge treatment apparatus described above and sequentially performing the following steps.
(A) Step of collecting sludge from the bottom of the water (b) Step of dehydrating the collected sludge (c) Step of producing zeolite powder from the dehydrated sludge as a raw material (d) Step of converting the zeolite powder into a molded product (e ) A step of spreading the molded product on the bottom of the water.

  According to this method, sludge collected from the bottom of the water is converted into a zeolite molding and returned to the bottom of the water, so that sludge can be safely treated without adversely affecting the environment. Moreover, by spreading the zeolite molding on the sludge layer and covering the sludge layer, the environment of the processing target section can be improved without treating the sludge layer to the bottom. In addition, the zeolite moldings spread on the bottom of the water serve as a medium for aquatic organisms, which leads to an abundance of fishery resources.

  (6) The present invention is characterized in that in the sludge treatment method having the above-described configuration, sludge treatment is performed after a partition to be treated is surrounded by a partition wall.

  According to this configuration, even when sludge is collected or the zeolite molding is distributed, even if the sludge rises into the water and the water becomes contaminated, the contaminated water remains in the partition wall, so that the contamination is diffused outside the work area. It is possible to proceed with processing without having to do so.

  According to the present invention, sludge is treated with a floating body that floats on the surface of the water, so that sludge can be treated at a low cost at the place where sludge is present, and since sludge becomes a zeolite molded product, there are concerns about adverse effects on the environment. It can be returned to the bottom without doing it. Moreover, since the zeolite molded product may be distributed in water as soon as it is produced, it is possible to continue producing the zeolite molded product at full operation, and to treat sludge very efficiently. Moreover, by covering the top of the sludge layer with a zeolite molding, the environment of the processing target section can be improved without treating the sludge layer to the bottom. Furthermore, the water taken from the staying water area in the water is added to the water separated from sludge, and then the oxygen enrichment treatment is performed and the water is returned to the staying water area, so the staying water area often has high COD and high BOD. Can effectively improve water quality.

  Hereinafter, an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a sludge treatment apparatus.

  The main body of the sludge treatment apparatus 1 is a floating body 10 that floats on the water surface. The floating body 10 may be of any type. It may be a barge ship or a normal ship shape. It may have a navigation capability or may only be towed. It may be a mega float type. The floating body 10 is moored on the water surface of the sludge processing target section by a plurality of mooring lines 11 so that it does not drift and its orientation does not change.

  The following elements are loaded on the floating body 10. That is, a sludge collecting device 20 that collects sludge from the bottom of the water, a dehydration device 21 that dehydrates the collected sludge, a zeolite production device 22 that produces zeolite powder using the dehydrated sludge as a raw material, and a structure that uses the produced zeolite powder as a molded product. A granulating device 23, a spreading device 24 for spreading the zeolite molding on the bottom of the water, a wastewater treatment device 25 for treating the water separated from sludge, a refluxing device 26 for returning the treated water to the water, and water used in the zeolite production process. A water intake device 27 for water intake and a support plant 28 for supplying power necessary for sludge treatment.

  The dewatering device 21, the zeolite production device 22, the granulating device 23, the wastewater treatment device 25, and the support plant 28 each occupy a part of the floating body 10, but the sludge collecting device 20, the spreading device 24, the reflux device 26, and the water intake device. 27 is provided so as to hang from the lower surface of the floating body 10. Next, each component will be described.

  The sludge collecting device 20 moves the tip of the hose two-dimensionally or three-dimensionally, a hose that hangs down from the lower surface of the floating body 10, a pump (not shown) that sucks or pushes water into the dehydrator 21 through this hose. It consists of a manipulator (not shown).

  The dehydrator 21 separates sludge and sand sucked together with water from water, and includes a mechanical element including a centrifugal separation mechanism and a known filtration mechanism such as a bag filter and a belt filter.

  The zeolite manufacturing apparatus 22 adds sodium hydroxide to dehydrated cake-like sludge (including sand) and heats it to manufacture zeolite (micron-sized powder). On the other hand, the organic matter in sludge can be recovered as activated carbon.

The granulator 23 granulates zeolite powder, and forms a molded product having a specific gravity and a mass that settles quickly without floating in water or flowing in a water stream. The molded product can be a pellet having a particle size of about 10 mm, for example, and other shapes can be selected.
The shape of the molded product is free.

  The spreading device 24 includes a hose that hangs down from the lower surface of the floating body 10, a feeder (not shown) that feeds the zeolite molding in the granulating device 23 into the hose, and a two-dimensional or tertiary tip of the hose. It consists of a manipulator (not shown) that moves originally.

  The waste water treatment device 25 aerations the water separated from sludge and performs oxygen enrichment treatment. A part of the water taken by the water intake device 27 is also added to the water separated from sludge and subjected to oxygen enrichment treatment.

  The reflux device 26 includes a hose that hangs down from the lower surface of the floating body 10, a pump (not shown) that pushes the oxygen-enriched water into the hose, and a manipulator that moves the tip of the hose two-dimensionally or three-dimensionally ( (Not shown).

  The water intake device 27 includes a hose that hangs down from the lower surface of the floating body 10, a pump (not shown) that sucks or pushes water into the water tank 27a through the hose, and a manipulator that moves the tip of the hose two-dimensionally or three-dimensionally. (Not shown). The water stored in the water tank 27a is used as neutralized washing water in the zeolite powder manufacturing process, but a part of the water is added to the water separated from sludge as described above, and the wastewater treatment device 25 supplies oxygen. After being enriched, it is returned to the water from the reflux device 26.

  The support plant 28 supplies the power (electricity and heat) necessary for the production of zeolite powder, the production of zeolite pellets, and the driving of various pumps and conveyors. The engine, the gas turbine, and the compound that combines them. Any type of power system can be adopted. It is also possible to employ a configuration in which the floating body 10 is electrically propelled using the electric power generated by the support plant 28. Furthermore, fine adjustment for position control and position holding of the floating body 10 during work can be performed using an electric thruster.

  Next, the operation of the sludge processing apparatus 1 will be described. First, sludge is collected from the sludge layer S at the bottom of the water by the sludge collecting device 20. That is, the tip of the hose of the sludge collecting device 20 is brought close to the surface of the sludge layer S, and the pump is driven to suck sludge together with water. The sludge is sucked into the surface portion of the sludge layer S (for example, a layer having a depth of several tens of centimeters from the surface), and the sludge layer S is not sucked up to the bottom. If sludge is sucked, sand is usually sucked together. Move the tip of the hose two-dimensionally with a manipulator, and collect sludge evenly from a wide range.

  What is sucked by the sludge collecting device 20 is separated into water and other than water (sludge and sand, etc.) by the dehydrator 21. Water is sent to the wastewater treatment device 25, and the cake sludge and sand after dehydration are sent to the zeolite production device 22.

  In the zeolite production apparatus 22, sodium hydroxide is added to sludge and sand, which is further heated to produce zeolite powder. Organic matter in sludge becomes activated carbon.

  The zeolite powder is sent to the granulator 23 to be formed into a molded product.

  The zeolite molded product is supplied to the distribution device 24 by a feeder, and distributed to the bottom of the water from the tip of the hose of the distribution device 24. Spreading is performed on the sludge layer S after collecting sludge. The surface of the sludge layer S is covered with a sand-covering layer P of a zeolite molded product. The manipulator moves the tip of the hose two-dimensionally and distributes the zeolite molding evenly over a wide area.

  In this way, by covering the sludge layer S with the sand-covering sand layer P of the zeolite molded product, the environment of the processing target section can be improved without sucking the sludge layer S to the bottom and processing it. The zeolite-covered sand-covered layer P can purify both the water in contact with it and harmful substances generated from the sludge below by its chemical activity. Fishery resources will be enriched.

  The water intake device 27 takes in the neutralized washing water used in the zeolite powder production process. In the water, there is a flowing water area W1 near the surface where water is highly fluid due to inflow of river water and tides, and a stagnant water area W2 below which has low water fluidity. The water has high COD and high BOD. Water is taken from the stagnant water area W2.

  The taken water is stored in the water tank 27a and used as neutralized washing water. Part of the water is sent to the waste water treatment device 25 and added to the water separated from sludge.

  The waste water treatment device 25 aerates the received water and performs oxygen enrichment treatment. The reflux device 26 returns the oxygen-enriched water to the water. It is the staying water area W2 that is returned.

  Thus, by returning the water after the oxygen enrichment treatment to the staying water area W2, the activity of the aquatic microorganisms in the staying water area W2 is activated, and the water quality of the staying water area W2 having high COD and high BOD is greatly improved. .

  The sludge process is performed after a partition to be processed is surrounded by a partition wall. In the embodiment, the partition wall 31 is configured by a curtain suspended from the buoy 30.

  By doing so, even when sludge is collected or when zeolite pellets are distributed, even if sludge rises into the water and the water becomes polluted, the polluted water remains in the partition wall 31, so that the pollutant is removed from the outside of the work section. It is possible to proceed with the processing without diffusing.

    Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

    INDUSTRIAL APPLICABILITY The present invention can be used for treating sludge at the bottom of the water regardless of whether it is a water area such as the ocean, a river, or a lake.

Schematic configuration diagram of sludge processing equipment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sludge treatment apparatus 10 Floating body 20 Sludge collection apparatus 21 Dehydration apparatus 22 Zeolite production apparatus 23 Granulation apparatus 24 Spreading apparatus 25 Wastewater treatment apparatus 26 Reflux apparatus 27 Water intake apparatus 28 Support plant 31 Bulkhead

Claims (6)

  The floating body includes a floating body that floats on the water surface.In this floating body, a sludge collection device that collects sludge from the bottom of the water, a dehydration device that dehydrates the collected sludge, a zeolite production device that produces zeolite powder using the dehydrated sludge as a raw material, A sludge treatment device, wherein a granulating device for forming the zeolite powder into a molded product and a spraying device for distributing the molded product on a water bottom are loaded.   The sludge treatment apparatus according to claim 1, wherein a wastewater treatment apparatus for oxygen-enriching the water separated from the sludge and a reflux apparatus for returning the oxygen-enriched water to the water are loaded.   In the wastewater treatment device, the oxygen-enriched treatment is performed after adding water taken from the retained water area in the water to the water separated from sludge, and the water after the oxygen-enriched treatment is returned to the retained water area by the reflux device. 3. The sludge treatment apparatus according to claim 2, wherein the sludge treatment apparatus is returned.   The sludge treatment apparatus according to claim 1, wherein a support plant that supplies power necessary for sludge treatment is loaded on the floating body. A sludge treatment method using the sludge treatment apparatus according to any one of claims 1 to 4 and sequentially performing the following steps:
(A) Step of collecting sludge from the bottom of the water (b) Step of dehydrating the collected sludge (c) Step of producing zeolite powder from the dehydrated sludge as a raw material (d) Step of converting the zeolite powder into a molded product (e ) A step of spreading the molded product on the bottom of the water.   The sludge treatment method according to claim 5, wherein the sludge treatment is performed after a partition to be treated is surrounded by a partition wall.

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