JP3964525B2 - Antibacterial and anti-algae granular material - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an antibacterial and anti-algal particulate material for preventing the growth and growth of fungi and algae mixed in water mainly by immersing cooling tower cooling water in water such as a central water supply.
[0002]
[Prior art]
Domestic wastewater and general industrial wastewater are drained after being treated so that they meet the required drainage standards. Living wastewater and general industrial wastewater are treated from the viewpoint of water quality and treatment costs. A large amount of wastewater sludge is generated because solid-liquid separation is carried out by adding agglomeration precipitates in addition to chemical treatment and biochemical treatment.
In the past, this large amount of wastewater sludge was exclusively left to industrial waste disposal companies, but in recent years it has been banned from being dumped at sea, and there are significant restrictions on waste disposal sites, as well as harmful substances. Combined with the risk of secondary pollution due to leaching, industrial waste costs are also rising, and as a result, producers are concerned about not only management costs but also future production activities.
[0003]
For this reason, producers can reduce the weight and volume of wastewater sludge by dehydrating water contained in a large amount in the wastewater sludge using a mechanical means such as a filter press, or by heating and drying the wastewater sludge. Although the absolute amount of wastewater associated with production is large, although it has been attempted to reduce weight and volume using temporary mechanical means and heating means, it is necessary to solve management cost pressure and disposal problems. It does n’t come.
[0004]
On the other hand, energy saving and resource saving are regarded as important issues in industrial activities today, and this makes it possible to recycle and reuse cooling water used in large quantities in offices, stores, and production factories. In other words, so-called water supply for repurifying the once-used water and using it for purposes other than drinking is rapidly spreading.
However, the circulating water and the tap water have not only a large amount of bacteria and gonococci but also pathogenic fungi. In particular, Legionella bacteria and the like have been bred to cause serious consequences such as death.
In addition, the circulating water and the tap water cause the generation and growth of algae such as blue-green algae, and this may adhere to the circulator and the piping and cause a clogging accident, or adhere to the fountain. I have problems that damage the waterscape.
[0005]
As a result of intensive studies in view of such problems, the inventors have included wastewater sludge discharged from wastewater treatment of domestic wastewater and general industrial wastewater containing organic matter by firing at a temperature of 300 to 800 ° C. It is formed to be porous with the evaporation and volatilization of a large amount of water and volatile matter, and the organic matter is carbonized, and its composition components are generally 45 to 55% silicon oxide, 20 to 25% aluminum oxide, and 3 to 4 iron oxide. 0.5%, calcium oxide 3 to 4.5%, magnesium oxide 2 to 3%, potassium oxide 1.9 to 2.8%, sulfur oxide 1.6 to 2.5%, other phosphorus oxides, sodium oxide, etc. Forming a calcined sludge lump having a weight ratio of 2 to 1.6%, crushing the calcined sludge lump to a required size, and further performing secondary firing at 900 to 1100 ° C. Carbide is burned off as silicon oxide melts, and hard particles can be formed as it hardens, and silver or copper holding oligodynamic action is uniformly supported on the outer surface and porous inner surface of such particles. As a result, the present inventors have found that antibacterial fungi and algae-preventing algae mixed in water can be effectively and over a long period of time.
[0006]
[Problems to be solved by the invention]
That is, the present invention can effectively and antibacterial against fungi and algae over a long period of time by being immersed in and brought into contact with circulating water or medium water flow channels in which fungi and algae are mixed, and is extremely inexpensive. The object is to provide an antibacterial and anti-algae granular material.
[0007]
[Means for Solving the Problems]
The technical means adopted by the present invention in order to solve the above-mentioned problem is to burn wastewater sludge discharged by treating wastewater containing organic matter and general industrial wastewater at a temperature of 300 to 800 ° C. By transpiration and volatilization of the moisture contained in a large amount of water and the contained volatile matter, it became a porous calcined sludge mass formed with many micropores and then crushed to the required size, thus Porous calcined sludge crushed to the required size is secondarily calcined at a temperature of 900 to 1100 ° C. to burn off the carbide and harden it by melting silicon oxide, and the components are fixed to each other. In this configuration, silver or copper is uniformly supported on the outer surface and the porous inner surface of the granular material.
[0008]
[Action]
Since the present invention is configured as described above, it has the following effects. In other words, wastewater sludge discharged from wastewater treatment of domestic wastewater and general industrial wastewater containing organic substances contains not only about 70 to 90% of water but also volatile components such as fats and oils. However, by firing this wastewater sludge at a temperature of 300 to 800 ° C., it is possible to dry and solidify with the transpiration and volatilization of moisture and volatile components, and there are many micropores with the transpiration and volatilization of moisture and volatile components. A porous fired sludge lump is formed which is formed and contains a mixture of carbides obtained by carbonizing organic substances.
Thus, this calcined sludge lump is crushed to a required size and subjected to secondary firing at a temperature of 900 to 1100 ° C., so that the carbide is burned off and silicon oxide is melted to fix the composition components to each other. And a hard granular body is formed.
And since silver or copper is uniformly supported on the surface of the granular material or the porous inner surface, it is possible to circulate water or medium with a large contact area by immersing it in circulating water or middle water mixed with fungi and algae. Since it comes into contact with water and the oligodynamic action of silver and copper works from its contact surface, it exhibits antibacterial effects against fungi and an algal control effect against algae.
[0009]
【Example】
In the following, the embodiment of the present invention will be described in detail. The wastewater sludge used in the present invention is a wastewater mixed with organic matter such as domestic wastewater or general industrial wastewater by biochemical treatment or combined with coagulation sedimentation treatment in the biochemical treatment. The wastewater sludge discharged and then discharged is used, and the wastewater sludge contains about 70 to 90% by weight of water.
[0010]
The waste water sludge having such a high moisture content is dried and solidified, and the contact surface area is increased and a large number of so-called micropores are formed. In this case, the firing temperature is used. It varies depending on the water content of wastewater sludge, the contact surface area formed by drying and solidification, the size and number of micropores, etc. It must be dried and solidified to a messy size.
For this purpose, in the case of wastewater sludge having a high moisture content of about 70 to 90% by weight, the transpiration or volatilization of moisture and volatile matter is moderated at a low temperature that can be achieved during firing, preferably in the range of about 300 to 400 ° C. It is desirable from the viewpoint of formation of a lump accompanying dry solidification.
[0011]
On the other hand, when wastewater sludge is dehydrated with a filter press or the like and the wastewater sludge whose water content is dehydrated to about 50 to 70% is used, the wastewater sludge is baked at a sufficiently high temperature to maintain the viscosity, A massive calcined sludge mass can be formed while rapidly evaporating or evaporating internal moisture and volatile matter to form a large number of micropores.
[0012]
By the way, the method of use of the present invention is to immerse the present invention formed in substantially the same particle size in a flow path such as cooling tower circulating water or waterworks and to circulate it, and to achieve antibacterial and algal protection by its oligodynamic action. Since it is a thing, it is necessary to grind | pulverize the baking sludge lump formed to a required particle size beforehand. In such a case, the particle size of the present invention for practical use is usually about 5 mm to a maximum of about 30 mm, so the crushed sludge lump is also crushed to a particle size of this level. .
Although there are no particular restrictions on the crushing method, since it is desired that the present invention is used in a spherical shape, it is convenient to crush the calcined sludge mass in a shape close to a spherical shape. For this reason, the use of a ball mill or the like is usually proposed.
[0013]
Thus, the calcined sludge crushed to the required particle size is further subjected to secondary calcining at a high temperature of 900 to 1100 ° C. This secondary calcining burns away residual carbides and oxidizes the composition components. By melting silicon to impart toughness and hardness that can withstand practical use, and fixing for insolubilization of components and the like mixed in trace amounts.
In such a case, the specific firing temperature, firing time, etc. of the secondary firing differ depending on the physical properties of the fired sludge, the crushed particle size, required toughness, hardness, etc., but waste water sludge having a moisture content of 60% is used. In a calcined sludge obtained by crushing a calcined sludge mass calcined at 600 ° C. for 1 hour to a particle size of about 6 mm, a secondary calcining temperature of 930 to 950 ° C. and a calcining time of about 60 to 90 minutes are a standard.
[0014]
There are no particular restrictions on the firing method in the secondary firing, but the shape of the sludge lump is various in the state of being crushed to the required size, but in the use of the present invention is a spherical shape Therefore, it is more preferable that the spheroidization can be performed in the secondary firing. An example of the secondary firing method satisfying such a condition is as follows. Spherical granulates can be formed by supplying the smashed sludge from above the furnace and firing it while rolling the heating furnace.
[0015]
Thus, the surface of the granular body formed by the secondary firing and the porous inner surface have silver or copper for effectively and long-terming the so-called oligodynamic action of the bactericidal and algicidal action by the trace amount of metal ions. It is supported uniformly.
The silver or copper supporting means is not particularly limited, but it may be firmly attached to the surface and the porous inner surface so as to be substantially exposed at a ratio of 0.1% by weight or more. Can be put to practical use.
As a silver or copper supporting means suitable for the present invention, a silver nitrate solution previously diluted to a required dilution ratio is used for supporting silver, and copper sulfate is further used for supporting copper. By immersing the granular material in these solutions to sufficiently infiltrate the silver nitrate solution or the copper sulfate solution, and then neutralizing the nitric acid or sulfuric acid in the alkaline solution. Thus, the present invention carrying silver or copper is formed.
[0016]
【The invention's effect】
As described above, according to the present invention, the waste water sludge generated in large quantities is reduced to approximately 1/8 to 1/10 only by firing at a temperature of 300 to 800 ° C., and has a very large contact surface area. The calcined sludge lump is formed, and the calcined sludge lump is crushed to an appropriate size and secondarily fired at a temperature of 900 to 1100 ° C., so that residual carbides are burned out and silicon oxide is melted. Along with this, not only toughening and hardening are achieved, but also a small amount of composition components are fixed and insolubilized, so that a highly safe granular material free from the risk of secondary pollution is formed.
And since silver or copper is uniformly supported on the surface of the granular material or the porous inner surface, it is simply immersed in a flow path such as circulating water or middle water in which fungi and algae are mixed. It has many features such as anti-dynamic and anti-algae properties are effectively exhibited, and anti-bacterial and anti-algae properties are maintained for a long time by being supported on the porous inner surface. It can be said that it is an antibacterial and alga-proof granular material.

Claims (1)

Wastewater sludge discharged during wastewater treatment of domestic wastewater or general industrial wastewater is calcined at a temperature of 300 to 800 ° C. to form a porous calcined sludge mass, which is crushed to a required size, and thus 900 to 900 Carbide is burned out and hardened by secondary firing at a temperature of 1100 ° C., and silver or copper is uniformly supported on the surface and porous inner surface at a ratio of at least 0.1% by weight. Antibacterial and anti-algae granular material.