JP5031495B2 - Wastewater treatment unit at repair or dismantling site - Google Patents

Description

  The present invention relates to a wastewater treatment unit at a repair or dismantling site (particularly repair). More specifically, the present invention relates to a building, a work or a structure (hereinafter referred to as “building or the like”) using a building material containing a fibrous or powdery harmful substance such as asbestos (hereinafter referred to as “asbestos or the like”). )) After the primary filtration, the asbestos-containing water generated in the water washing step prior to the refurbishment or dismantling of the wastewater is further drained through a microfiltration that is a secondary filtration. It is.

  Here, a case where the harmful substance is asbestos (fibrous harmful substance), that is, a case where the harmful substance is applied to an asbestos molded plate will be described as an example. However, the wastewater treatment method at the repair or dismantling site of the present invention can be applied even when the harmful substance is not fibrous.

  The asbestos-containing building material here refers to the on-site coating process in which asbestos-containing paint is sprayed on the inner and outer wall base materials in addition to the asbestos-containing molded plates as interior and exterior materials (slate corrugated sheet, roofing slate, slate board, etc.) Includes building materials.

  Further, the present invention will be described by taking, as an example, a process that occurs in a water washing operation at a repair site of an exterior material. However, the present invention is also applicable to an interior material.

  Asbestos (asbestos) is prohibited in principle because of its carcinogenicity to the respiratory system (lung cancer and malignant mesothelioma).

  On the other hand, asbestos does not rot, has heat resistance and chemical resistance, and is lightweight, so it has been frequently used as a building material together with industrial materials. In particular, it has been used in large quantities as a raw material for building materials such as asbestos boards, slate, tiles, and as a filler for spray paint.

  For this reason, when the existing building is renovated, the surface, roof or outer wall is usually washed with water. Prior to this water washing, it is usually necessary to carry out the site in a state where the site is closed (sealed system), that is, with a vinyl sheet or the like applied to prevent scattering, from the viewpoint of dust generation and scattering prevention.

  And, in the closed workplace, so that dust is not generated as much as possible, the exterior material (outer wall or roofing material) is sprayed with water and washed with hand or high pressure water, or with ultra high pressure. Remove the paint film at the same time by washing with water.

  A large amount of drainage is produced in the washing process of these exterior materials. And the asbestos content rate contained in the said waste_water | drain is low, and the regulation regarding the said waste_water | drain does not exist at this stage.

  However, in particular, asbestos damage has recently become prominent, and there has been a demand for more stringent regulations on asbestos outside (external) emissions. That is, further reduction in the asbestos content in the wastewater has been demanded.

  Due to the recent increase in social interest in the environment, there is a demand for filtering and draining water after washing.

  At this time, focusing on only the fiber length of asbestos (average 2 mm at about 3 μm to 50 mm), it is necessary to use a microfilter incorporating a filter medium having a trapping particle diameter (filtering capacity) of 2 to 5 μm. Conceivable. Examples of the microfilter include those manufactured and sold under the trade name “Mini Water” by Critical Industries, Inc., USA.

  However, asbestos is a very fine fiber (single fiber diameter: 0.02 to 0.03 μm). For this reason, there is a possibility that asbestos may pass through the filter medium having a filtration capacity of 2 to 5 μm of the microfilter, and it was necessary to verify whether or not asbestos is sufficiently captured with respect to the filtrate (drainage).

  For this reason, the present inventors use a cartridge filter having a nano-order (1 μm (1000 nm) or 0.2 μm (200 nm)) filtration capacity higher than the filtration capacity (5 μm) in the above-mentioned “mini water”, and asbestos-containing wastewater (sewage) ) Filtration was possible to some extent, but the filtration capacity was insufficient to meet the stricter regulations on asbestos drainage in the future (Table 1 (E) and (See (F)).

  In addition, it was found that the filter medium was clogged early, the pressure loss increased, and the filter had to be replaced frequently. That is, the useful life of the cartridge filter was short.

  The present inventors are not familiar with patent documents that affect the patentability of the present invention.

By the way, the search result of the logical expression “(dismantling OR refurbishment) AND (asbestos) AND (safety)” in the gazette text search (summary + claims) on the JPO homepage was 4 hits ( (As of August 31, 2007).
JP 2007-117909 JP 2007-107359 A JP 2007-063784 JP 2007-063780

  In view of the above, the present invention can be expected to significantly reduce the useful life (amount of serviceable amount) of the microfilter, and further expect to further reduce the asbestos content in wastewater, particularly asbestos content in wastewater. The purpose is to provide a wastewater treatment unit at the site of refurbishment or dismantling.

  As a result of diligent development in order to solve the above-mentioned problems, the present inventors have come up with a wastewater treatment unit at the repair or dismantling site of the following configuration.

It is a unit used when draining the asbestos- containing water generated in the washing process prior to repairing or dismantling the building , work or structure using asbestos- containing building materials,
Water collecting means, crude Ro over means, and, microfiltration unit, and a first transporting pipe which connects the said water collecting means and the coarse filtration means, and, between said microfiltration means and said coarse filter means Equipped with a second transport piping to connect ,
The coarse filtration means is a filter tank body, a gravity filtration surface can be formed on the entire opening surface, and the filter medium is detachably mounted in a flat state ,
The filter medium is a non-woven fabric or a water-permeable sheet , and the water-permeable sheet is selected from a porous plastic sheet, woven paper, or woven fabric (a laminate of woven fabrics having different weaving methods, directions, and pitches). It is characterized by.

In the above structure, the nonwoven fabric may be a spunbonded, basis weight of the spunbond is desirable to use those 40 ~200g / m ^2.

  In each of the above configurations, the filter medium is held by a filter medium receiver having a perforated plate part or a frame part with a filtration-supporting surface that is detachable together with the filter medium from the filter tank body, and a clamping ring that is appropriately clamped with the filter medium receiver is used. And it can be set as the structure with which the said filtration tank main body is mounted | worn.

  The wastewater treatment unit at the repair or dismantling site of the present invention has a remarkable effect when applied to the case where the harmful substance is a fibrous harmful substance, particularly asbestos. In addition, when the wastewater treatment unit of the present invention is applied to asbestos-containing dust, a microfiltration secondary filtration means having a minimum capture particle size of less than 1 μm is used.

  In addition, the waste water treatment method in the repair thru | or the dismantling site using the waste water treatment unit of this invention becomes the following composition.

After the primary filtration of the asbestos- containing water generated in the washing process performed prior to refurbishment or dismantling of a building, work or structure using asbestos-containing building materials, using a coarse filtration means, further a fine filtration means A wastewater treatment method at a repair or demolition site that drains through secondary filtration to be used,
The coarse filtration means is attached to the filtration tank body with a filter medium capable of forming a gravity filtration surface on the entire opening surface in a detachable flat state ,
The filter medium is a non-woven fabric or a water-permeable sheet, and the water-permeable sheet is selected from a porous plastic sheet, woven paper, or woven fabric (a laminate of woven fabrics having different weaving methods, directions, and pitches). It is characterized by.

  Next, the present invention will be described in further detail based on preferred embodiments.

  (A) FIG. 1 shows a model diagram of a unit used in the wastewater treatment method in the repair or dismantling site of the present invention.

The unit of the present embodiment basically includes a water collecting means 12, a coarse filtration means (primary filtration means: coarse filter) 14, and a fine filtration means (secondary filtration means: fine filter) 16.

  1) As the water collecting means 12, for example, when the outer wall is washed with water, the water collecting means 12 is constituted by a water collecting tank 18 disposed at the lower end of the outer wall and a pit (collecting tank) 20 disposed at a drain outlet of the water collecting tank 18. . Note that the pit 20 is usually an on-site embedded type by preparing a molded body, but it may be on-site construction.

  Further, although not shown in the drawing, a dust removing means (strainer) formed of a wire net or cloth (including non-woven fabric) may be appropriately disposed at the outlet of the water collecting basin 18 or the opening of the pit 20. .

  2) The coarse filtration means (coarse filter: primary filtration means) 14 is provided with a filter medium (gravity filtration member) 24 capable of forming a gravity filtration surface on the entire opening surface of the filtration tank body 22 in a detachable manner. 24 shall be the structure which is a nonwoven fabric or a water-permeable sheet.

  Here, the filter medium 24 is attached to the filter medium receptacle 26 in which the filtration-compatible surface 26a that is detachable together with the filter medium 24 from the filter tank body 22 is a perforated plate portion (FIG. 1 (A)) or a frame portion (FIG. 1 (B)). Further, the gravity filtration member 29 is formed by being held by the holding ring 28, and the gravity filtration member is detachably attached to the filtration tank main body 22. A pair of handles 26b are formed at the upper end of the filter medium receptacle 26 so that the gravity filtration member 29 can be easily attached and detached. The frame portion may be formed by a flat bar, but may be formed by a belt-like net.

The aperture ratio of the perforated plate portion or the frame portion in the filtration corresponding surface 26a is 10 to 98%, preferably 50 to 95%, and the opening area of each hole is 1 to 10,000 mm ² , preferably 3 to 3000 mm ² , More desirably, the thickness is 100 to 1000 mm ² .

  Here, the filter medium 24 may be only the entire surface of the porous plate portion (bottom) of the filter medium receiver 26, but normally, the filter medium 24 is also configured to cover the inner peripheral wall of the filter medium receiver 26 as shown in the figure. This configuration is desirable because it can prevent asbestos from adhering to the inner peripheral wall of the filter media receiver 26.

  Further, the filter medium receiver 26 can be integrated with the filtration tank main body 22, and the filter medium 24 can be attached and detached together with the holding ring 28. Further, the filter medium 24 can be abolished (eliminated) as a bottomed cylindrical molded body that can be fitted to the filter tank body 22 from above. An appropriate weight (for example, 50 to 500 g of a metal rod or mineral block) may be placed on the filter medium 24 instead of the sandwiching ring.

  However, the nonwoven fabric forming the filter medium 24 is preferably not a molded body but flexible. After use, it can be folded and made smaller, placed in a plastic bag and discarded, etc., and handling is easier compared to a filter medium of a molded body that is a rigid body.

  Further, when the filter medium 24 lays a non-woven fabric or a water-permeable flexible sheet body, slow natural filtration by gravity (so-called “gravity filtration”) becomes possible. For this reason, it is estimated that a long fiber length (for example, 3 μm or more) can be easily captured.

  Examples of the water-permeable flexible sheet include porous plastic sheets, woven paper, and woven fabrics (for example, woven fabrics having different weaving methods, directions, and pitches).

  In the case of a nonwoven fabric, the type is not particularly limited, and includes dry-type nonwoven fabrics such as chemical bonds and needle punches, spunbonds (including those formed by pressing with a thermal calendar simultaneously with spinning, and wet nonwoven fabrics (several). It is possible to use a sheet of fiber with a diameter of about mm mm. Of these, spunbond is particularly desirable because it is easy to obtain a thin sheet-like nonwoven fabric (about 0.1 to 0.5 mm) and has good asbestos (fibrous harmful substance) trapping properties.

In particular, ensure that if fibrous harmful substances asbestos, basis weight, desirably from about 20 to 200 g / m ^2, more desirably about 40~150g / m ^2, and most preferably about 50 to 100 g / m ² is doing.

  The constituent fibers of the nonwoven fabric are not particularly limited, such as polyolefin-based, polypropylene-based, polyester-based, and nylon-based fibers.

  Specifically, "Elves" (olefin type), "Syntex" (polypropylene type), "Wywi" (nylon type) from Unitika Ltd., "Unicel" (polyester type) from Teijin, "Etalplus" from Asahi Kasei (Polyester type) that is marketed under each registered trademark name can be used.

  The water collecting means 12 and the coarse filter (coarse filtration means) 14 are usually connected by a first liquid feed pipe 32 provided with a first liquid feed pump (pump pump) 30. As described above, when no dust removing means (strainer member) is provided at the outlet of the catchment pit or the pit opening, a strainer (dust removal wire net) 34 is provided at the suction port 32a of the first liquid feed pipe 32. Wear it.

  3) As the microfilter (microfiltration means) 16, a general-purpose microfilter, for example, one manufactured and sold under the trade name “Mini Water” from the aforementioned US Critical Industry can be used. The cartridge filter 16a attached to the microfilter has a nano-order filtration ability (minimum trapping particle of less than 1 μm), preferably 0.1 to 0.5 μm (100 to 500 nm), more preferably 0.2 μm. A filter having a filtering ability of (200 nm) is used.

  The coarse filter 14 and the fine filter 16 are connected by a second liquid feed pipe 38 having a second liquid feed pump 36.

  In addition, the both sides or one side of the pump of 1st and 2nd liquid feeding piping can also be made into tube piping. Furthermore, the discharge side of the microfilter 16 which is a microfiltration means is connected to the sewage pit 50 or the like so that drainage is possible (see FIGS. 2 to 3).

  (B) Next, a repair method using the waste water treatment unit will be described.

  Basically, it includes the following 1) curing process, 2) on-site drainage system construction process, 3) washing process, 4) painting process, and 5) curing removal process. In addition, in the following description, the thing corresponding to the above-mentioned waste water treatment unit attaches | subjects the same figure code | symbol, and abbreviate | omits all or one part of those description.

1) Curing process:
First, a dust-proof curing sheet 44 is stretched on a scaffold 42 assembled around the outer wall 40a to be repaired of the building 40, and a surface curing sheet 46 is laid between the outer wall 40a and the scaffold.

2) On-site wastewater treatment system construction process:
A water collecting bowl (for example, made of plastic) 18 is temporarily installed with a temporary holding plate material 19 along the foundation 40b of the outer wall 40a. In addition, it is desirable to seal with the curing tape etc. in the clearance gap between the water collecting bowl 18 and the foundation 40b.

  And the water collection tank (water collection pit) 20 is formed in the arbitrary one places or the plurality of places of the water collection tank 18. The suction port 32 a of the first liquid feed pipe 32 of the first liquid feed pump (pump pump) 30 is arranged at the bottom of the water collecting tank 20, and the discharge port 32 b of the first liquid feed pipe 32 of the water pump 30. Are made to face the opening (water inflow portion) of the filtration tank body 22 and the arrangement portion of the gravity filtration member 29. A shower may be attached to the discharge port 32b.

  The coarse filter 14 (filter tank body 22) and the fine filter (secondary filtration means) 16 are connected by the second liquid feeding pipe 38 as described above. Further, the outlet of the microfilter 16 can be drained to a sewage pit 50 or the like via a drainage system (usually existing) 48.

  Then, trial operation such as pumping, air venting of the microfilter 36, and a water supply / drainage system is performed.

  In the above description, the case where the simple temporary arrangement method is used is taken as an example of the water collection method, but the water collection method is not limited to the above. In the case of roof refurbishment, the water collecting means collects water in the primary separation tank using the existing dredge, and drops the gravity from the primary separation tank to the primary filtration tank (coarse filter) or uses a pump. May be introduced.

3) Water washing process As described above, the repair method is to wash the outer wall with water or high pressure water.

  And the used water which generate | occur | produced by this watering or high-pressure water washing is introduce | transduced into the coarse filter (primary filtration means) 14 through the said water collection tank 18 grade | etc.,.

  In addition, in the case of using a reflux hose for used water in washing with a hood during high-pressure or water washing, it is introduced into the coarse filter 14 via the reflux hose.

  At this time, used water (sewage: asbestos-containing sewage) generated by water spraying or high-pressure washing is subjected to a gravity filtration member 29 on the filtration tank body 22 before being secondarily filtered by the microfilter (microfiltration means) 16. Surprisingly, most of the asbestos in the asbestos-containing sewage is captured by performing primary filtration with the coarse filter (coarse filtration means) 14 formed. For this reason, the load on the microfilter which is the secondary filtration means is remarkably reduced, and as a result, the asbestos content in the wastewater is further reduced as compared with the case where the asbestos-containing sewage is directly passed through under pressure. . Of course, the cartridge filter replacement period (durable treatment amount) in the microfilter is also greatly increased.

  In addition, used filter media (nonwoven fabric) and cartridge filters are managed and stored and discarded at predetermined locations.

4) Coating step The outer wall after washing with water is dried by applying a conventional undercoating or further overcoating.

  For example, the base coat is a flexible acrylic resin-based or polymer cement-based base material, and the top coat is an acrylic resin-based, urethane resin-based, or acrylic silicone resin-based exterior finish paint. Perform by brushing or roller coating.

5) Curing removal process Thus, after painting, the surface curing sheet 46 and the dust-proof curing sheet 44 are removed, and each curing sheet is disposed of at a managed disposal site for asbestos.

These curing sheets are also stored and disposed of in accordance with laws and regulations.
<Test example>

  A filtration test for asbestos-containing sewage conducted to confirm the effect of the present invention will be described.

  The following samples were used.

    (A) Stock solution: 15 g of amosite dissolved in 30 L of fresh water and uniformly dispersed.

(B) Primary filtrate: gravity filtered with spunbond (polyester, basis weight: 70 g / m ² ).

    (C) Secondary filtrate: The primary filtrate filtered through a cartridge filter (0.2 μm).

    (D) Blank liquid: A liquid obtained by filtering blank water (tap water) with a cartridge filter (0.2 μm).

    (E) Microfiltrate (1): A stock solution filtered through a cartridge filter (1 μm).

    (F) Microfiltrate (2): Stock solution filtered through cartridge filter (0.2 μm).

  Each of the above-mentioned samples was collected by the indicated amount, filtered and dried with a membrane filter, and subjected to counting analysis with a phase contrast microscope. “F / L” means “the number of asbestos fibers in 1 L of the sample”. Table 1 showing the results shows that in the present invention, the asbestos-containing sewage discharged from the wastewater treatment method at the repair or demolition site contains substantially no asbestos (Test Example (C)). It is “not detected” as in the case of filtering blank water (Test Example (D)).

It is a model figure of the unit used for the wastewater treatment method in the repair thru | or the demolition site of this invention. It is the whole arrangement | positioning elevation schematic of the waste water treatment method at the time of applying to a repair site using the unit of FIG. Similarly, it is a schematic plan view.

Explanation of symbols

12 Water collection means 14 Coarse filtration means (primary filtration means: coarse filter)
16 Microfiltration means (secondary filtration means, microfilter)
18 Catchment 20 Catchment tank (collection pit)
22 Filtration tank body 24 Filter medium 26 Filter medium receiver 26a Filtration compatible surface 28 Nipping ring

Claims (7)

It is a unit used when draining the asbestos-containing water generated in the washing process prior to repairing or dismantling the building, work or structure using asbestos-containing building materials,
Water collection means, coarse filtration means, microfiltration means, first transport piping connecting between the water collection means and coarse filtration means, and between the coarse filtration means and the microfiltration means With a second transport pipe to connect,
The coarse filtration means is a filter tank body, a gravity filtration surface can be formed on the entire opening surface, and the filter medium is detachably mounted in a flat state,
It said filter media, waste water treatment unit in the renovation or demolition, characterized in that a nonwoven fabric having a basis weight 40~200g / m ^2.   The wastewater treatment unit at a repair or dismantling site according to claim 1, wherein the nonwoven fabric is spunbond. The wastewater treatment unit at a repair or dismantling site according to claim ² , wherein the basis weight of the spunbond is 40 to 150 g / m2.   The refurbishment according to claim 1, 2 or 3, wherein the filter medium is held by a filter medium receiver having a perforated plate portion or a frame portion as a filtration support surface, and is detachably attached to the filter tank body. Or wastewater treatment unit at the dismantling site.   The wastewater treatment unit at a repair or demolition site according to claim 4, wherein the filter medium is further held by the filter medium receiver using a holding ring that is held together with the filter medium receiver.   6. The wastewater treatment unit at a refurbishment or demolition site according to any one of claims 1 to 5, wherein the trapping minimum particle size of the microfiltration means is less than 1 μm. After the primary filtration of the asbestos-containing water generated in the washing process performed prior to refurbishment or dismantling of a building, work or structure using asbestos-containing building materials, using a coarse filtration means, further a fine filtration means A wastewater treatment method at a repair or demolition site that drains through secondary filtration to be used,
The coarse filtration means is attached to the filtration tank body with a filter medium capable of forming a gravity filtration surface on the entire opening surface in a detachable and flat state.
The filter media, waste water treatment method in renovation or demolition, characterized in that the nonwoven fabric of basis weight 40~200g / m ^2.

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