JPH06104173B2 - Filter material made from paper sludge - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter material used for filtering liquid or gas.

[0002]

2. Description of the Related Art Carbon has an excellent filtering ability as conventionally known. And carbon filter media are used in many fields.

[0003]

However, the conventional carbon-made filter media have the drawback of being expensive. By the way, at the present time, a paper mill has a problem in processing the paper sludge generated in the paper manufacturing process. This is because if the paper sludge is poured into the river as it is, it will accumulate as sludge, which will lead to pollution of the river and the ocean. Therefore, the current method for treating paper sludge is generally to dehydrate and incinerate.

In view of the above situation, the present invention has developed a carbon filter material using paper sludge as a raw material, which eliminates pollution caused by the paper sludge and does not realize cost reduction of the carbon filter material. It is what

[0005]

In order to achieve the above object, the present invention provides a paper sludge which is dehydrated from a state generated in a papermaking process to a water content of about 30 to 50%, and, for example, phosphoric acid. A mixture of calcium chloride and potassium permanganate, or a mixture of carbonic acid and cobalt chloride mixed solution and the like, a carbonization aid, and a clay that is baked and hardened at a temperature lower than the temperature at which carbon burns,
Knead the paper sludge, carbonization aid and clay,
The present invention provides a filter material obtained by baking the kneaded product at a temperature at which carbon does not burn.

[0006]

When the kneaded product of the paper sludge, clay and carbonization aid is fired, the paper sludge is carbonized to become carbon. At this time, carbonization of the paper sludge is promoted by the function of the carbonization auxiliary material. Since the clay is baked at a temperature lower than the temperature at which the carbon burns, the carbon remains in the clay without being burned. This carbon has an excellent filtering ability.

[0007]

EXAMPLES Examples of the present invention will be described below. The paper sludge used as the raw material is a large amount contained in the wastewater of the paper mill, and this is subjected to a centrifuge or a filter press to obtain a water content of about 30 to 50%. The carbonization aid is a mixed solution of phosphoric acid (H ₃ PO ₄ ) and calcium chloride (CaCl ₂ ), potassium permanganate (KMnO ₄ ), or a mixed solution of potassium permanganate and cobalt chloride (CaCl ₂ 6H ₂ O). And so on. By appropriately using these carbonization aids, a filter medium suitable for the application can be obtained. This point will be described later. As the clay, one that can be fired at a temperature at which carbon does not burn, that is, at a temperature of about 450 to 470 ° C. is used. For example, high-quality elutriated clay is applicable.

Next, a carbonization auxiliary is mixed with dehydrated paper sludge, clay is added to the mixture, and the mixture is kneaded with a mixer.
Granulate about 3.5 mm. Then, the grains are packed in a jar and put in an electric kiln and fired at a temperature of about 450 to 470 ° C. Thus, the granular filter material 1 as shown in FIG. 1 is obtained. The cost of the filter medium 1 is reduced by continuously firing it in a rotary kiln.

Next, a specific example of the filter material 1 of the present invention will be described.

[0010]

SPECIFIC EXAMPLE 1 A carbonization auxiliary made of a 3% solution of potassium permanganate and a paper sludge after dehydration are mixed at a ratio of 1: 9, and this and clay are kneaded at a ratio of 4: 6.
Then, the kneaded material was granulated and then fired at a temperature of 450 ° C. for about 2.5 hours. Water containing iron was filtered with the filter material thus obtained. The results are shown in Table 1.

[0011]

[Table 1]

[0012]

[Specific Example 2] The carbonization aid used in Specific Example 1 was replaced with a mixture of a 3% solution of cobalt chloride and a 3% solution of potassium permanganate in a ratio of 1: 1. A filter medium was manufactured under the same conditions as above. Filtration for removing manganese was performed with this filter medium. The results are shown in Table 2.

[0013]

[Table 2]

[0014]

[Example 3] The carbonization aid used in Example 1 was replaced with a mixture of a 3% solution of phosphoric acid and a 3% solution of calcium chloride in a ratio of 1: 1 except that the same conditions as in Example 1 were used. To produce a filter medium. Also in the filter material of the specific example 3, the specific example 1
The iron removal effect was similar to that of the filter material. Further, a test was carried out for using this filter medium for decolorization of dyeing wastewater. The results are shown in Table 3. In the test, a two-column type filtration tower having a tank diameter of 150 mm and a filter layer length of 1000 mm was used, and the dyed wastewater from which sludge had been removed was filtered through the filtration tower.

[0015]

[Table 3]

Although the embodiments have been described above, needless to say, the present invention is not limited to these embodiments.

The filter material of the present invention has the following excellent effects. It contributes to pollution prevention by using paper sludge as a raw material, which has been difficult to dispose. Paper sludge is essentially a waste material, so it costs almost no raw material,
Moreover, since it can be manufactured by a simple manufacturing method in which the carbonization auxiliary material and clay are kneaded and fired, a carbon filter material can be provided at a very low cost. In a filter medium coated with a chemical such as manganese zeolite or manganese sand, the chemical is exfoliated by long-term use or backwashing, which causes a problem of deterioration of filtration ability. Even if the surface is worn, the filtration performance does not decrease because carbon is mixed up to the point. Since clay is used as a shaping material, the filtering material can be processed into any shape. Therefore, the present invention can be applied to various fields, for example, by forming a cylindrical shape as shown in FIG. 2 through which exhaust gas is passed and adsorbing harmful substances in the exhaust gas.
It is harder than a 100% carbon filter material because the whole shape is maintained by the clay that has been baked and solidified. Therefore,
Rapid contact filtration is possible. Even if impurities or the like adhere to the filter medium, it can be easily regenerated by baking the surface. Since the shrinkage rate of clay and paper sludge during firing is different, countless fine holes are formed inside the filter medium. The fine pores increase the surface area of the filter material, which dramatically increases the filtering ability.

[Brief description of drawings]

FIG. 1 is a perspective view of a granular filter medium.

FIG. 2 is a perspective view of a cylindrical filter medium.

[Explanation of symbols]

 1 ... Filter material

Claims (1)

[Claims] 1. A paper sludge that is dehydrated from a state generated in a papermaking process to a water content of about 30 to 50%, a carbonization auxiliary material for promoting carbonization of the paper sludge, and carbon burns. A paper sludge comprising a clay that is baked and hardened at a temperature lower than a temperature, the paper sludge, a carbonization aid and clay are kneaded, and the kneaded product is baked and hardened at a temperature at which carbon does not burn. Filter material used as a raw material.