JP2007044621A - Sludge treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sludge treatment method in which a flocculant is added to sludge so as to form flock and drain water with a mesh bag body. <P>SOLUTION: The sludge treatment method is provided with a step for adding the flocculant to the sludge as industrial waste and stirring to form the flock and a step for solid-liquid separating by pouring the flock containing water to the mesh bag body 4 and hanging the mesh bag body 4 to drop out only the water outside of the mesh bag body. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sludge treatment method. More specifically, the present invention relates to a sludge treatment method in which sludge separated into solid and liquid by a flocculant is subjected to moisture adjustment with a mesh bag and then discarded or recycled.

  In sludge treatment at small and medium-sized water purification plants, the sludge is sucked with a suction car and carried to a final disposal site or a recycling factory. Alternatively, as shown in FIG. 3, a dewatered cake that has been solid-liquid separated into a floc form by a flocculant tank 103 and a centrifugal dehydrator 104 mounted on a mobile dewatering vehicle 102 and dehydrated into a final disposal site in a transport vehicle, Alternatively, there is a processing step of carrying out to a recycling factory (see, for example, Patent Document 1).

  In addition, the sludge is transported to an existing sun drying floor, and the sludge solidified by evaporating the water contained in the sludge by the sun is collected by heavy machinery such as bucket trucks, and then transported to the final disposal site by a transport vehicle. There are processing steps to do.

JP-A-10-337598

  However, in the processing method of transporting the sludge as it is to a final disposal site or a recycling factory, the amount of processing is large because it is transported in a state of containing a large amount of water, and it is very consignment for sludge treatment. There is a big cost problem.

  In addition, in the method of treating sludge with a mobile dewatering vehicle, it is necessary to install various facilities such as a sludge receiving tank and a transfer pump necessary for processing operations in the mobile dewatering vehicle within the site of a water purification plant. A flocculant is added to the sludge transferred from the tank to the flocculant tank to perform solid-liquid separation, and the floc formed by the flocculant is separated from the moisture contained in the sludge by a centrifugal dehydrator. Since the daily processing amount is limited to 20 to 30 m3, when the outsourced processing amount is 150 m3, 5 to 7.5 days are required. It takes about 7 to 10 days in total for the installation and cleanup of the equipment.

  Therefore, during this treatment period, there is a problem of noise generation due to the operation of the centrifugal dehydrator and the pump, and since one sludge treatment is limited, if the amount of sludge is large, the treatment period becomes longer and the cost is increased. There is a problem that becomes high.

  In addition, when sludge is transferred to a sun-dried bed and sun-dried, it takes a long time to evaporate the water in the sludge and a large floor area, resulting in a problem of very low processing efficiency.

  The present invention was devised in view of the above points, and provides a sludge treatment method in which a floc is formed by adding a flocculant to solid-liquid separated sludge to drain water with a mesh bag. It is intended.

  In order to achieve the above object, a sludge treatment method according to the present invention includes a step of adding a flocculant to sludge as industrial waste and stirring to form a floc, and a sludge having the floc formed therein. Pour into the mesh bag body and suspend the mesh bag body to drop only the water to the outside of the mesh bag body to perform individual liquid separation.

  Here, flocs are formed by adding flocculant to sludge, and when this is stored in a mesh bag body and suspended, only moisture hangs down due to its own weight and drops from the mesh bag body. It becomes possible to perform individual liquid separation.

  Further, after sludge is separated into individual liquids, the sludge is dried into sun sludge to form dry sludge. By using this mesh bag as a container for transportation, the transshipment work process can be omitted.

  In addition, it is possible to reduce the cost by reusing the dried sludge after discarding or recycling it from the mesh bag.

  According to the sludge treatment method of the present invention, flocculant is added to sludge to form a flock, and this is stored in a mesh bag body and suspended to perform efficient draining independent of a dehydrator. It becomes possible.

  In addition, it is possible to dry the sun in a state of being stored in a mesh bag body, and after drying it, it can be stored in a mesh bag body and transported to a final disposal site or a recycling factory, thereby eliminating work steps such as refilling as before. And work efficiency becomes very high.

  Furthermore, the mesh bag can be reused, and noise is hardly generated because no mechanical device is used in the sludge treatment process.

Hereinafter, embodiments of the present invention will be described with reference to the drawings to provide an understanding of the present invention.
FIG. 1 is a flowchart showing an example of a sludge treatment method to which the present invention is applied.

  Here, for example, water taken from a river or the like is purified at the water purification plant 1 and sterilized with chlorine, and then distributed to each household. In this water purification plant, solid-liquid separation is performed by adding a flocculant to turbid water to aggregate and sediment turbid components.

  Therefore, the turbid component that is turbid in the water to be treated has a negatively charged surface and is dispersed by an electric repulsive force. By adding a flocculant composed mainly of polyaluminum chloride (PAC), which is positively charged to these turbid components, the turbid components are agglomerated by the flocculant and precipitated, and the supernatant water and Solid-liquid separation into precipitated sludge.

  Next, the solid-liquid separated sludge is stored in a temporary tank or the waste mud pond 2. And the sludge stored in the waste mud pond 2 is transferred to the reaction tank 3 by a pump.

  A floc is formed by adding a flocculant mainly composed of calcium oxide (CaO) to the sludge charged into the reaction tank 3 and stirring the sludge.

  The floc sludge is stored in the mesh bag 4 and drained. This mesh bag is made of a material that has elasticity and excellent drainage, such as polypropylene, and is sludge that is flocked to have a mesh shape with a smaller pore diameter than flock. Will not leak from the mesh bag.

  Therefore, as shown in FIG. 2, a plurality of mesh bag bodies 4 are suspended from a suspension frame 5 temporarily installed in a water purification plant, and floc sludge is poured into these mesh bag bodies. It hangs down by its own weight, oozes out of the flock and falls from the mesh bag body 4, and individual liquid separation of sludge (separation between sludge and water that can be discharged into the river) becomes possible.

  Even after the filtration is completed in this manner, the moisture content of the sludge separated into individual liquids is further reduced by performing sun drying for 7 to 10 days with the plurality of mesh bags 4 suspended outdoors. The weight can be reduced by about 80% from the original sludge.

  Also, during the period of sun drying, there is no foreign matter (garbage, dead leaves, empty cans, etc.) scattered from the outside in the mesh bag. (The recycling rate is 100% with purified water sludge).

  And when the dried sludge is transported to the recycling factory as final disposal, it can be used as a container for transportation by loading it into the vehicle with a crane or the like with the dried sludge stored in the mesh bag. Since it is mesh-like, the dry sludge accommodated does not scatter outside.

  Therefore, since the mesh bag body is used as it is as a container for transporting the dried sludge, there is less labor for transshipment, and the empty mesh bag body after the dried sludge is discharged at the transport destination is brought back to the site and re-used. Use (usually about 3 times).

  In addition, although the present Example explained in full detail the sludge process which generate | occur | produces in a water purification plant, it can apply with respect to various sludges, such as activated sludge, such as construction construction site sludge and a food housing complex.

  In the sludge treatment method of the present invention, flocs can be flocated by adding a flocculant to sludge generated under various conditions, and the sludge can be discharged to a river or the like by pouring it into a mesh bag and suspending it. Only fresh water can be filtered.

  And it becomes possible to omit refilling work by making dry sludge by sun drying for several days, and carrying out the mesh bag body. In addition, since the number of mesh bags is determined according to the amount of sludge treated, it is possible to handle even when the amount of sludge treated is small or large, and it is possible to secure stable treatment capacity. Become.

  Furthermore, compared to the treatment with a mobile dewatering vehicle, there is no need to use a dewatering device in the sludge treatment process, so no mechanical noise is generated and the mesh bag is used according to the sludge treatment amount. Since the number of bodies is determined, there is no waste and efficient sludge treatment is possible.

The flowchart figure which shows an example of the sludge processing method to which this invention is applied is shown. It is explanatory drawing which shows the suspended state of the mesh bag body in the sludge processing method to which this invention is applied. It is a flowchart figure which shows the sludge process process by the conventional mobile dehydration vehicle.

Explanation of symbols

1 Water Purification Plant 2 Mud Pond 3 Reaction Tank 4 Mesh Bag 5 Hanging Frame

Claims (4)

Adding flocculant to sludge as industrial waste and stirring to form floc;
A sludge treatment method comprising the steps of pouring the sludge forming the floc into a mesh bag and dropping the liquid only outside the mesh bag by hanging the mesh bag to separate the individual liquids. . The sludge treatment method according to claim 1, wherein after the individual liquid separation is performed, sun drying is performed to form a dry sludge. The sludge treatment method according to claim 2, wherein the mesh bag is used as a container for transporting dry sludge. The sludge treatment method according to claim 3, wherein the sludge treatment method is used for separate liquid separation after the mesh bag body is used as a container for transporting dry sludge.

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