JPH07215786A - Treatment of dredging sludge and cleaning method of static water system - Google Patents

Abstract

PURPOSE:To provide a treatment method capable of easily composting dredging sludge and a cleaning method of ponds, etc., utilizing this method. CONSTITUTION:Sludge-contg. water sucked together with sludge is subjected to a filter treatment using dry algae as filter media, by which the sludge is adhered to the dry algae and the dry algae stuck with the sludge are utilized as compost. Working regions 3a, 3b... are set at the pond 1 by sealingly enclosing these regions with pollution diffusion preventive films 2 hung down from the water surface. Recovering of dirt and dredging of the sludge by suction are progressed within these working regions. The sucked sludge-contg. water and the polluted water in the working region generated by diffusion of the sludge are subjected to a filter treatment using the dry algae as the filter media, by which the used dry algae stuck with the sludge are utilized as the compost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating dredging sludge and a method for cleaning a static water system using the same, and particularly a cleaning method suitable for a static water system which is strongly required to maintain a landscape such as a pond in a park. Regarding

[0002]

2. Description of the Related Art There are many cases where the sludge accumulated at the bottom is dredged to preserve the water quality of rivers and lakes.
Due to this, the treatment of dredging sludge has become a problem. That is,
Most of the dredged sludge is treated by landfill, but it causes problems due to the limit of landfill capacity, and although some attempts to use it as compost, it requires complicated secondary processing. Therefore, the reality is that it is not practical.

[0003] In addition, in static water systems such as ponds and lakes, especially in ponds where a lot of people gather, such as in parks, empty cans and bottles, and even large-sized garbage are dumped at the bottom. It is the basis for damaging the landscape by winning the pool. For this reason, it is necessary to carry out a cleaning operation for collecting sludge with dredging of sludge in a certain cycle. In such cleaning work, how to treat the dredged sludge becomes a problem, and how to prevent the water in the pond from being totally polluted due to the sludge diffusion accompanying the cleaning work. Is also a problem.

Regarding this point, regarding the conventional method, regarding the sludge treatment, conventionally, the dredged sludge was dehydrated and then disposed as described above. For this reason, there is a problem similar to the above, and there is also a problem that the polluted water is refluxed due to the dehydration treatment, resulting in a polluted state for a long period of time. On the other hand, for the diffusion of pollution, the contaminated water in the working area was filtered by a rapid filter, but since there is a lot of sludge and suspended solids, it is necessary to backwash it frequently. It was polluted again by the reflux of water, which was an extremely wasteful work.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a treatment method capable of easily composting dredged sludge, and also to a pond as described above. The purpose of the present invention is to provide a method that enables efficient and environmentally friendly cleaning.

[0006]

The method for treating dredged sludge according to the present invention is to apply sludge to dry algae by subjecting sludge-containing water sucked together with sludge to filtration treatment using dry algae. Dry algae attached to sludge is used as compost.

This is an effective utilization of the characteristics of dried algae. That is, dry algae has sufficient fertilizer suitability for itself, as mentioned as one of the special fertilizers based on the Fertilizer Control Law, and it is easy to give a preferable net structure for filtration and has high filterability. There is. By effectively utilizing both of these characteristics as in the method of the present invention, the sludge composting process can be greatly simplified. That is, the sludge and the dried algae can be integrated at the same time as the purification of the sludge-containing water by the filtration treatment, and the dried algae with the sludge can be made into a compost by simply performing the aging treatment. As a result, the utilization of dredged sludge for compost can be made practical.

The method for cleaning a pond according to the present invention, which utilizes such a sludge treatment method, sets a work area of an appropriate area by sealingly surrounding it with a pollution diffusion prevention film hanging from the water surface to the bottom, and performing this work. The sludge is dredged by collecting and sucking the waste in the area, and the sludge-containing water that has been sucked in and the contaminated water in the work area that is generated due to the diffusion of the sludge are subjected to a filtering process using dry algae as a filter medium. Used dry algae with sludge attached is composted and used.

According to this method, since the work is carried out within the work area which is set to be closed by the pollution diffusion preventing film, it is possible to prevent the diffusion of the pollution due to the cleaning work to a wide range of the pond.

Further, since dredging of sludge is carried out by suction and the sucked sludge-containing water is subjected to a filtering treatment with dried algae as a filter material, used dry algae is composted and reused. The sludge can be treated reliably without problems such as the re-generation of polluted water in the sludge dewatering treatment, and therefore the work can be efficiently carried out.
Sludge can be effectively used as a component of compost.

Further, since the polluted water in the work area is treated in the same manner as the sludge-containing water, the post-treatment of the pollution associated with the cleaning work should be performed as efficiently as the sludge-containing water. The sludge generated thereby can also be effectively utilized as a component of compost.

[0012] In each of the above methods, it is preferable to use dried oaksamo as the dried algae. The reason is as follows. Ooafusamo is a perennial plant of the family Amaranthaceae, and its life form normally takes the form of a water-extracting plant. That is, as schematically shown in FIG. 4, the aerial leaf B is erected on the water at a length of about 10 to 20 cm, while the spiral main stem K is placed in the water or the water bottom for several meters or more depending on the water depth. It has a life form in which many roots r are stretched from the surface of the main stem into the soil at the bottom of the water and rooted. Then, adjacent individuals form a colony capable of resisting washout by entwining their spiral main stems with each other. In particular, according to the research conducted by the inventor of the present application, by making the roots in a state that cannot be submerged in the soil, much more roots are grown than in the natural state to form an extremely excellent filter structure, and the main stem By providing conditions that physically hinder the elongation of the stem, the spiral state of the main stem also becomes more dense and forms a filter structure. In addition, Oofusamo has a structure as described above and has a large surface area, so that it is easy to dry. Therefore, an excellent dried algae filter can be easily obtained only by appropriately air-drying the giant sardine that has been cultivated in a natural state or in a condition where a filter structure is easily formed. Moreover, for example, TN has about 13% TN,
T-P ₂ O ₅ is about 1%, T-K ₂ O is about 2%, T-Ca
O about 1.7%, T-MgO about 1%, TC about 292
%, The nitrogen and phosphorus contents are particularly high, and it is also suitable as a fertilizer.

After filtering and removing sludge with dried algae as described above, it is more preferable to filter finer suspensions and malodorous components. As a filter medium for that purpose, a filter medium having a high filtering power and being capable of being reused after being used in some form is desirable, and a filter medium using a material having a soil improving agent suitability is particularly desirable. Typical examples of such a filter medium are porous calcium silicate hydrate, charcoal, and husk charcoal, and it is more preferable to use them in an appropriate combination.

Therefore, it is desirable that the filtration device used in this method has a structure in which a dried algae layer, a porous calcium silicate hydrate layer, a charcoal layer, a chaffed charcoal layer, and a charcoal powder layer are laminated in this order from the upstream side. Becomes

[0015]

EXAMPLES As an example of the present invention, an example will be described below in which cleaning of a pond having conditions such as Shinobazu Pond in Ueno Park is carried out mainly by human power.

First, as shown in FIG. 1, a plurality of work areas 3 are enclosed along a shore of a pond 1 by a pollution diffusion prevention film 2 in a closed manner.
(3a, 3b, ... 3x) is set. The area of each work area is 30 to 40 m ² . The pollution diffusion prevention film 2 is shown in FIG.
As shown in FIG. 2, a float 2f is attached to the upper end of the waterproof membrane material 2c, and a weight (not shown) is attached to the lower end,
It is installed while suspended by the float 2f.

When the setting of all the work areas is completed, the work is proceeded in order for each work area 3a, 3b, ... 3x by dividing the work of collecting dust and the work of dredging sludge and the filtration process accompanying it. Specifically, first, a staff member for collecting dust collects dust in the work area 3a (3a, 3b depending on the number of personnel). During this time, the person in charge of dredging and filtering process will proceed with the setup. Then, when the dust collection work of the work area 3a is completed, the dust collection work person proceeds to the next work area 3b, and the person in charge of dredging and filtering processes the work area 3a.
Will proceed with the dredging and filtration process.

As shown in FIG. 3, the filtration device used for the filtration treatment is a dried algae layer 4 filled with dried oofsamom in order from the upstream side, and a porous calcium silicate hydrate filled with granular porous calcium silicate hydrate. The structure 9 has a structure in which a product layer 5, a charcoal layer 6 filled with granular charcoal, a chaffed charcoal layer 7 filled with chaff charcoal, and a charcoal powder layer 8 filled with powdered charcoal are laminated, and the frame body 9 thereof is It is made of wood and is covered with a waterproof sheet (not shown). Its volume size is vertical,
Beside it is 7.5 m ³ of 1.2 m height each 2.5 m.
The thickness of each layer is 40 cm, 20 cm, 3 in order from the top.
It is set to 0 cm, 10 cm, and 10 cm.

Filtration by this filtration device is carried out by sprinkling sludge-containing water and polluted water sucked up by the suction pipe 10 from the upper side by the sprinkling nozzle 11, and taking out the filtered water from the lower side and returning it to the pond. The watering rate is set to 70 to 100 liters / minute.

Most of the sludge is filtered by the filter device in the dried algae layer 4, and the porous calcium silicate hydrate layer 5 and below mainly function to filter fine suspensions and malodorous components. Therefore, the dried algae layer 4 becomes clogged as the treatment progresses. Therefore, the dried algae layer 4 should be properly monitored.
Replace dried oofsamo. The used dried Oofusamo is thrown into a collection box prepared in advance and stored, and finally transported to a composting plant for processing, and then reused as compost. Here, it is desirable to add a deodorant in order to prevent the bad odor of the sludge during storage in the collection box, but as the deodorant, for example, a wood vinegar solution that does not hinder the subsequent composting is used. To use.

[0021]

As described above, the method for treating dredging sludge according to the present invention is intended to facilitate the composting of sludge by using dried algae as the filter medium. It is possible to make practical use of sludge for compost.

Further, in the pond cleaning method according to the present invention, as described above, the setting of a closed work area by the pollution diffusion preventing membrane and the filtration of sludge-containing water or polluted water with dry algae are combined. Therefore, it is possible to prevent the spread of pollution due to cleaning work over a wide area of the pond, to efficiently treat sludge and polluted water, and to perform post-treatment of sludge without waste, making it an environmentally friendly treatment. it can.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an installation state of a work area according to the present invention.

FIG. 2 is a vertical sectional view of a work area shown in FIG.

FIG. 3 is a vertical cross-sectional view of a filtration device.

FIG. 4 is a diagram of a life form of a giant sardine.

[Explanation of symbols]

 1 Pond 2 Pollution Diffusion Prevention Membrane 3 Working Area 4 Dry Algae Layer 5 Porous Calcium Silicate Hydrate Layer 6 Charcoal Layer 7 Rice Hull Coal Layer 8 Charcoal Powder Layer

Claims (5)

[Claims] 1. A method for treating sludge dredged from rivers, lakes and marshes, wherein sludge-containing water sucked together with sludge is subjected to a filtration treatment using dried algae as a filter medium to attach the sludge to the dried algae. A method for treating dredged sludge, characterized in that dried algae attached to sludge is used as compost. 2. The method for treating dredged sludge according to claim 1, wherein dried officinalis is used as the dried algae. 3. The method according to claim 1 or claim 2, wherein a filter medium made of a material having a soil conditioner suitability is additionally used in addition to the dried algae.
The method for treating dredging sludge described in. 4. The dredging sludge according to claim 3, wherein a filter device is used in which a dried algae layer, a porous calcium silicate hydrate layer, a charcoal layer, a rice charcoal layer and a charcoal powder layer are laminated in this order from the upstream side. Processing method. 5. A cleaning method for dredging sludge or collecting dust accumulated at the bottom of a static water system such as a pond or a lake, which is enclosed by a pollution diffusion prevention film hanging from the water surface to the bottom. Set a work area with an appropriate area, and proceed with dredging of sludge by collecting and sucking dust in this work area, and dry the polluted water in the work area that is generated by diffusion of sucked sludge-containing water and sludge. A static water-based cleaning method, wherein a filtration treatment using algae as a filter medium is performed so that used dry algae having sludge attached thereto is used as compost.