JP6216163B2 - Agglomeration aid for porous charcoal, filter aid for porous charcoal, production method thereof, and water treatment method - Google Patents

Description

The present invention relates to an agglomeration aid for porous charcoal used in a solid-liquid separation process for separating a solid content from a suspension water to be treated containing solids such as fine particles in water treatment such as wastewater treatment and water purification, and The present invention relates to a filter aid for carbon and a water treatment method.

In conventional water treatment, flocs are formed using a flocculant and an agglomeration aid for the separation of fine particulate solids such as suspended substances and turbidity components, and solids separation systems such as gravity sedimentation and flotation separation, And filtration is performed.

In the agglomeration process, for example, in a system in which fine particles such as colloidal particles are suspended, it is not easy to efficiently perform solid-liquid separation in a short time, and the processing equipment is increased in size and requires processing time. Have the problems.

In the filtration process, since fine particles block the filter medium, it is not easy to perform continuous and efficient filtration. For this reason, in the aggregation treatment and the filtration treatment, an aggregation aid and a filtration aid using a porous material such as diatomaceous earth are used.

Patent Document 1 discloses a flocculation method for removing impurities such as suspended substances in raw water using an inorganic flocculating agent and an organic flocculating agent.

JP 2008-264723 A

Although there is an abundance of diatomaceous earth itself, high-quality diatomaceous earth that is easy to mine and can be used for water treatment is not necessarily inexhaustible. In addition, the disposal of the diatomaceous earth aid after the coagulation treatment and filtration treatment can hardly be reduced, so there are some cases where it is used for cement materials, etc., but most are waste.

Therefore, the object of the present invention is to use porous charcoal produced from organic waste such as rice husk, so that solid-liquid separation can be efficiently performed with a small addition amount, and the volume of waste after treatment can be reduced. An object is to provide an agglomeration aid for porous charcoal, a filter aid for porous charcoal, and a water treatment method thereof.

The inventor investigated the turbidity, sedimentation rate, and floc diameter of the supernatant liquid when various porous charcoal and flocculant were added to the suspension water to be treated. As a result, selection of porous rice husk charcoal with a carbonization temperature of 500 ° C. to 600 ° C. and a flocculant, and the addition ratio are important, and when this property is specified, improvement in sedimentation rate and good floc growth are observed, Based on this finding, the present invention has been reached.

The method for producing a coagulant aid and filter aid of the present invention comprises carbonizing organic matter such as rice husks while stirring in an oxygen-free atmosphere, and activation treatment by dry distillation gas or water vapor generated from raw materials during thermal decomposition. It is characterized by doing.

According to the present invention, raw materials such as rice husks are fixed with high-purity carbon while maintaining the natural fine structure of the raw materials, and have ultra-fine pores developed by activation treatment and have a large specific surface area. It becomes a high-performance porous charcoal, and a filter medium having a performance comparable to or exceeding the function of a coagulant aid and filter aid for diatomaceous earth.

In general, many organic suspended substances are negatively charged in the neutral region of pH 5 or higher because of functional groups separated from the surface of the organic substance. In addition, many inorganic suspended substances, such as silt, are negatively charged in the neutral range because the isoelectric point of silicic acid is about pH 1-2.

The main function of the aggregating agent in such a system is to cancel these surface charges, cancel the electric repulsive force between the suspended fine particles, and agglomerate by van der Waals force or the like.

Now, since the surface potential in the liquid of the carbide is negative like the suspended substance as described above, aggregation is unlikely to occur due to the electric repulsive force simply by throwing the porous charcoal into the suspended water. Therefore, if the flocculant is poured into suspension water in advance, the surface charge of the suspended matter is offset or positively charged, and then the porous charcoal is thrown into the system, the suspended matter is found in the negatively charged carbide pores. Will be captured. Alternatively, when a polymer flocculant is used, suspended solids are taken into the pores of the carbide by polymer crosslinking.

Furthermore, the pores of the porous coal in the present invention are activated by dry distillation gas and water vapor generated from the raw material during carbonization in addition to maintaining the natural fine structure of the raw material. It is distributed over a wide range from μ to several liters. This covers the diameter of fine particles that are difficult to agglomerate, and the fine particles are taken into such pores and constrained by electrical or polymer cross-linking, so that agglomerates are quickly formed. , Facilitates precipitation and filtration.

Thus, unlike the diatomaceous earth etc., the aggregate in the case of using porous charcoal as an agglomeration aid and filter aid can reduce the volume of the aggregate by rolling or burning.

When the target suspended substance is an organic substance, fuel can be used by drying the aggregate. In addition, recycling is possible by performing reprocessing with a reduction sterilization carbonization machine or the like.

As mentioned above, porous coal can be manufactured from organic waste such as rice husks, so it can be supplied in large quantities at low cost, from the perspective of reducing waste, reducing carbon dioxide emissions, and effectively using resources. Is also effective.

The invention according to claim 1 is an agglomeration aid for porous charcoal used for the separation treatment of fine solid particles such as suspended substances and turbidity components, wherein the agglomeration aid for porous charcoal is rice husk It is an agglomeration aid for porous charcoal having a pore size ranging from 50 μm to 0.3 nm.

The invention according to claim 2 is a filter aid for porous charcoal used for the separation treatment of particulate solids such as suspended substances and turbidity components, wherein the filter aid for porous charcoal is rice husk A filter aid for porous charcoal, characterized in that it is a porous charcoal having a pore size in the range of 50 μm to 0.3 nm.

The invention according to claim 3 is an agglomeration aid for porous charcoal used for the separation treatment of fine solid particles such as suspended substances and turbidity components, wherein the agglomeration aid for porous charcoal is rice husk A charcoal, which is carbonized at a temperature in the range of 500 ° C. to 600 ° C. with stirring in an oxygen-free atmosphere and having a pore size in the range of 50 μm to 0.3 nm This is a method for producing an agglomeration aid for carbon.

The invention according to claim 4 is a filter aid for porous charcoal used for the separation treatment of particulate solids such as suspended substances and turbidity components, wherein the filter aid for porous charcoal is rice husk A charcoal, which is carbonized at a temperature in the range of 500 ° C. to 600 ° C. with stirring in an oxygen-free atmosphere and having a pore size in the range of 50 μm to 0.3 nm It is a manufacturing method of the filter aid of the porous charcoal characterized by being charcoal.

The invention according to claim 5 is a treatment tank for charging a suspension, a coagulant aid supplier for coagulating and filtering the suspension, a filter aid supplier, and the suspension. a water treatment method using a filtration filter for filtering said agglomeration aid is used flocculation aids porous coal according to claim 1, wherein the filter aid is a filter aid of the porous coal according to claim 2 It is a water treatment method characterized by using an agent.

According to the agglomeration aid for porous charcoal according to claim 1 or 3 , it is possible to provide an agglomeration aid for porous charcoal that can be efficiently solid-liquid separated with a small addition amount and can reduce the volume of waste after treatment. .

According to the filter aid for porous coal according to claim 2 or 4 , it is possible to provide a filter aid for porous coal that can be efficiently solid-liquid separated with a small addition amount and can reduce the volume of waste after treatment. .

According to the water treatment method of the fifth aspect, it is possible to provide a water treatment method in which solid-liquid separation is efficiently performed with a small addition amount, and the volume of waste after the treatment can be reduced.

According to the present invention, porous charcoal produced from organic waste such as rice husks is used, and solid-liquid separation can be efficiently performed with a small addition amount, and the volume of waste after treatment can be reduced. An agglomeration aid for charcoal, a filter aid for porous charcoal, and a water treatment method thereof can be provided.

The carbonization apparatus for producing the aggregation aid of the porous coal of this invention, and the filter aid of porous coal. Diagram of experiment to create 1000ppm kaolin simulated suspension water. State after 3 minutes after adding powder flocculant to 1000ppm kaolin simulated suspension water. State after 5 minutes after adding powder flocculant to 1000ppm kaolin simulated suspension water. Flock state 5 minutes after adding powder flocculant to 1000ppm kaolin simulated suspension water. Initial state of adding powder flocculant + porous charcoal (rice husk charcoal) to 1000ppm kaolin simulated suspension water. State after 3 minutes after adding powder flocculant + porous charcoal (rice husk charcoal) to 1000ppm kaolin simulated suspension water. State after 5 minutes after adding powder flocculant + porous charcoal (rice husk charcoal) to 1000ppm kaolin simulated suspension water

The agglomeration aid for porous charcoal of the present invention is an agglomeration aid for porous charcoal used in the separation treatment of fine particle solids such as suspended substances and turbidity components, and the agglomeration aid for porous charcoal Is characterized in that it is a porous coal carbonized at a temperature in the range of 300 ° C. to 900 ° C. with stirring in an oxygen-free atmosphere. Here, the agglomeration aid for the porous charcoal is rice husk charcoal, and the rice husk is carbonized at a temperature in the range of 500 ° C. to 600 ° C. while stirring in an oxygen-free atmosphere. Is in the range of 50 μm to 0.3 nm.

The filter aid for porous charcoal of the present invention is a filter aid for porous charcoal used for separation treatment of fine solid particles such as suspended substances and turbidity components, and the filter aid for porous charcoal Is characterized in that it is a porous coal carbonized at a temperature in the range of 300 ° C. to 900 ° C. with stirring in an oxygen-free atmosphere. Here, the filter aid for the porous coal is rice husk charcoal, and the rice husk is carbonized at a temperature in the range of 500 ° C. to 600 ° C. while stirring in an oxygen-free atmosphere. Is in the range of 50 μm to 0.3 nm.

The water treatment method of the present invention comprises a treatment tank into which a suspension is charged, a coagulant aid supplier for coagulating and filtering the suspension, a filter aid supplier, and the suspension. A water treatment method using a filtration filter for filtration, wherein the agglomeration aid is an agglomeration aid for porous charcoal and has a temperature in the range of 300 ° C to 900 ° C while stirring in an oxygen-free atmosphere. Porous charcoal carbonized at temperature,
The filter aid is a porous coal filter aid, which is a porous coal carbonized at a temperature in the range of 300 ° C. to 900 ° C. with stirring in an oxygen-free atmosphere. To do.

Here, the agglomeration aid for the porous charcoal is rice husk charcoal, and the rice husk is carbonized at a temperature in the range of 500 ° C. to 600 ° C. while stirring in an oxygen-free atmosphere. Is in the range of 50 μm to 0.3 nm. The filter aid for porous charcoal is rice husk charcoal, which is carbonized at a temperature in the range of 500 ° C. to 600 ° C. with stirring in an oxygen-free atmosphere, Is in the range of 50 μm to 0.3 nm.

Examples of the porous coal agglomeration aid, porous coal filter aid, and water treatment method of the present invention will be described below.

Example 1
FIG. 1 is a carbonization apparatus for producing the agglomeration aid for porous coal and the filter aid for porous coal of the present invention. The carbonization apparatus to be used is not limited to FIG. 1, and any type may be used as long as the carbonized object is carbonized in an oxygen-free atmosphere. Organic waste such as rice husk is carbonized.

As shown in FIG. 1, the carbonization apparatus (reduction carbonization processing apparatus) used in the present invention includes a rotating kiln 2 in which a spiral blade and a stirring blade 1 are arranged, and an interior of the one kiln 2. A combustion chamber 3 that stores the waste and organic matter, etc. that are input indirectly in an oxygen-free reduced state while accumulating heat in the organic matter etc. and supplies heat to the entire interior of one kiln 2, and a burner that faces the combustion chamber 3 A drying unit 2a having an area set inside the kiln 2 so as to evaporate water contained in the organic matter and the like introduced into the kiln 2 by indirect heating of the combustion chamber 3, and a drying unit 2a And a carbonized portion 2b having an area set inside the kiln 2 so as to be carbonized by indirectly heating and decomposing the organic matter or the like that has been dried.

The carbonization temperature is preferably 500 ° C. to 600 ° C. in the case of rice husk, but depending on the material, it may be set at 300 ° C. to 900 ° C. to perform carbonization.

(Example 2)
Simple Coagulation and Precipitation Test Using Porous Coal A simple coagulation and precipitation test was conducted using porous charcoal (rice husk charcoal) prepared by the carbonization apparatus shown in FIG. The rice husk charcoal used in the test is rice husk charcoal obtained by carbonizing rice husk at a carbonization temperature of 500 ° C. in an oxygen-free atmosphere.

Test method 1 g (1,000 ppm) of kaolin (suspension standard substance) in 1,000 mL of tap water and agitated simulated suspension water 1 g of polymer powder flocculant and 1 g of the same flocculant + coarsely pulverized porous charcoal 1g of rice husk charcoal was added and the effect of its precipitation was compared.

Test results When only the polymer flocculant is thrown, although flocculation occurs, the floc (aggregate) is soft and solid-liquid separation operations such as filtration are difficult. Moreover, the slime by the polymer flocculent has adhered to the wall surface of the beaker. FIG. 2 is a diagram of an experiment for creating a 1,000 ppm kaolin simulated suspension water, FIG. 3 is a state after 3 minutes after adding the powder flocculant to the 1,000 ppm kaolin simulated suspension water, and FIG. FIG. 5 shows a flock state 5 minutes after the powder flocculant is added to the 1,000 ppm kaolin simulated suspension water.

On the other hand, when porous charcoal is cast in addition to the flocculant, a relatively firm floc is quickly formed, and the floc diameter is growing greatly. Moreover, the turbidity of the supernatant liquid is low, and no slime occurs on the wall surface. Fig. 6 shows the initial state of adding powder flocculant + porous charcoal (rice husk charcoal) to 1,000ppm kaolin simulated suspension water, and Fig. 7 shows powder flocculant + porous charcoal into 1,000ppm kaolin simulated suspension water. FIG. 8 shows a state 5 minutes after the addition of the powder flocculant + porous coal (rice husk charcoal) to 1,000 ppm kaolin simulated suspension water.

(Example 3)
Coagulation precipitation test using porous charcoal A coagulation precipitation test was conducted using rice husk charcoal or cedar charcoal, which is a porous charcoal produced by the carbonization apparatus of FIG. In addition, the rice husk charcoal used for the test is rice husk charcoal obtained by carbonizing rice husk at a carbonization temperature of 300 ° C., 400 ° C., 500 ° C., 600 ° C., and 700 ° C. in an oxygen-free atmosphere.
Cedar charcoal is cedar charcoal obtained by carbonizing cedar at a carbonization temperature of 500 ° C. in an oxygen-free atmosphere.

Test Method Hyperfloc N type (manufactured by Hosho EG Co., Ltd.) was used as a powder flocculant, and a coagulation sedimentation test was performed according to the following procedure.
1) Add a predetermined amount of porous charcoal as a coagulant as needed to 500 mL of simulated water of kaolin (suspension standard substance) (1,000 mg / L) 2) Strength of 5 min. With a stirrer Stirring 3) Add 10 mg / L of powder flocculant and vigorously stir for 5 min. 4) Leave for 1 min. 5) Measure turbidity of the supernatant using a turbidimeter 6) Visually check the floc diameter Confirm and classify into indicators as shown in Table 1

Table 2 shows the results of an agglomeration test using an aggregating agent and porous charcoal.

It can be seen that when porous charcoal is added as compared with the case of agglomerating only with the powder aggregating agent, the transparency of the turbidity of the supernatant water is improved and the agglomerated floc diameter is increased. This tendency was confirmed in rice husk charcoal at a carbonization temperature of 400 ° C to 700 ° C, and the best results were obtained at a carbonization temperature of 500 ° C to 600 ° C. Moreover, even when using cedar charcoal with a carbonization temperature of 500 ° C., the same tendency was recognized, so it is considered that the carbonized material is not limited to rice husk, but also organic waste including wood.

According to the agglomeration aid for porous coal, the filter aid for porous coal, and the water treatment method of the present invention, solid-liquid separation can be efficiently performed with a small addition amount, and the volume of waste after treatment can be reduced. It is possible to provide a porous coal agglomeration aid, a porous coal filter aid, and a water treatment method thereof, which greatly contributes to solving environmental problems caused by various contaminated water, suspended water, and the like.

Rice husk charcoal has a larger particle size than general sand filter media (0.6 to 0.8 mm diameter), exhibits sufficient filtration performance with a filter, and does not clog. On the other hand, when only agglomerated floc is filtered directly with a filtration filter without using porous charcoal, clogging occurs immediately and filtration is impossible. In other words, ordinary sand filters and commercial filters require equipment with a large filtration area due to clogging problems, and it is necessary to increase the amount of wastewater required for backwashing and treatment, but this system requires a large amount of filtration aid. Filtration performance will be obtained.

The present invention is also effective for the purification of suspended water contaminated with radioactive cesium. The radioactive cesium released into the environment by the nuclear accident will adhere to silty soil or the like within a relatively short time and will not be easily detached. Therefore, purification of suspended water contaminated with radioactive cesium is equivalent to separating and removing suspended suspended solids to which radioactive cesium is fixed. According to the present invention, it is possible to reliably remove the suspended suspended matter having a small particle diameter, which is generally difficult to separate and remove, by incorporating it into the pores of the porous coal. Further, since the floc grows relatively large, the load on the filter medium is small, and for example, it can be filtered efficiently without causing clogging with a metallic spring filter or the like. Furthermore, since the sludge after solid-liquid separation contains a lot of porous coal, the volume can be reduced by a relatively simple operation such as rolling.

DESCRIPTION OF SYMBOLS 2 ... Kiln 2a Drying part 2b Carbonization part 2d Heat storage part 2c Internal space 2in Inlet 2out Outlet 3 ... Combustion chamber 3a ... Exhaust pipe 4 ... Heat source 5 ... Piping part 6 ... Cooling part 7 ... Deodorizing part 8 ... Dry distillation gas recovery part 9 ... Auxiliary heating source 10 ... Steam smoke path 11 ... Oilification section 12 ... Water distribution pipe 13 ... Fan 14 ... Hopper 15 ... Raw material supply pipe 16 ... Supply screw 17 ... Second discharge pipe 18 ... Cooling device 19 ... Connection pipe (downstream side) Exhaust pipe)
19a Downstream exhaust pipe upper pipe
19b Downstream exhaust pipe
20 ... Conveying screw 21 ... Conveying screw 22 ... Steam vent pipe (upstream exhaust gas pipe)
22a Upper side exhaust pipe upper pipe
22b Upstream exhaust pipe lower pipe
23 Chimney part 24 Circulation pipe 25 Degassing pipe 30 Connection part 60 Collection part P Input material Q Carbonized material

Claims (5)

An agglomeration aid for porous charcoal used in the separation treatment of fine particulate solids such as suspended substances and turbidity components, wherein the agglomeration aid for porous charcoal is rice husk charcoal and has a large pore size. Is a porous coal having a thickness in the range of 50 μm to 0.3 nm. It is a filter aid for porous charcoal used for the separation of fine particulate solids such as suspended substances and turbidity components, and the filter aid for porous charcoal is rice husk charcoal and has a large pore size. Is a porous charcoal in the range of 50 μm to 0.3 nm. An agglomeration aid for porous charcoal used in the separation treatment of fine particulate solids such as suspended substances and turbidity components, wherein the agglomeration aid for porous charcoal is rice husk charcoal and has a large pore size. Is a porous coal in the range of 50 μm to 0.3 nm, a method for producing an agglomeration aid for porous coal. A filter aid for porous charcoal used for separation of particulate solids such as suspended substances and turbidity components, wherein the filter aid for porous charcoal is rice husk charcoal, The porous charcoal is carbonized at a temperature in the range of 500 ° C. to 600 ° C. with stirring in an oxygen-free atmosphere and has a pore size in the range of 50 μm to 0.3 nm. A method for producing a porous carbon filter aid. Water using a treatment tank for charging the suspension, a coagulant aid supplier for coagulating and filtering the suspension, a filter aid supplier, and a filtration filter for filtering the suspension A processing method,
The method for water treatment according to claim 1, wherein the coagulant aid uses the coagulant aid for porous charcoal of claim 1, and the filter aid uses the filter aid for porous charcoal of claim 2 .

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