JPH08238483A - Production of seterilizing purifying agent - Google Patents

Abstract

PURPOSE: To easily obtain a sterilizing purifying agent by a method wherein a silver nitrate soln. and an ascorbic acid soln. are successively added to coral sand under stirring to deposit silver oxide on the surface of coral sand and aq. hydrogen peroxide is added to this coral sand to convert silver oxide to metal silver. CONSTITUTION: An aq. silver nitrate soln. and an aq. ascorbic acid soln. are successively added to coral sand under stirring to deposit silver oxide on the surface of coral sand. Aq. hydrogen peroxide with a concn. of 5% is added to and mixed with this coral sand under stirring to reduce deposited silver oxide to metal silver. This coral sand is drawn up from a reactor to be dehydrated and washed until silver nitrate becomes 5ppm or less and the washed one is dried to obtain a sterilizing purifying agent wherein silver is deposited on the surface of coral sand in an amt. near to a theoretical value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a sterilizing agent, and more particularly to a method for producing a sterilizing agent which is useful as a filter medium for drinking water in which coral sand is impregnated with silver.

[0002]

2. Description of the Related Art It is already well known that a material such as activated carbon, pumice, coral sand or the like having silver adhering to the surface thereof is used as a bactericide for water treatment. The method for producing a sterilizing purification agent using coral sand is roughly classified into a physical impregnation method and a chemical impregnation method. This physical impregnation method is to impregnate silver on the surface of the coral sand by a so-called silver mirror reaction without chemically reacting the coral sand as a base material, and the chemical impregnation method involves soaking the coral sand in a silver nitrate solution for a long time. , A method of reducing silver carbonate (Ag ₂ Co ₃ ) generated by the substitution reaction with a reducing agent and attaching silver to the surface of coral sand.

[0003]

However, when carrying out this silver mirror reaction, a silver-ammonium complex salt solution is prepared from a silver nitrate solution and aqueous ammonia, and this solution and coral sand are mixed and a reducing agent is added while heating. Since it is a method of impregnating silver on the surface of coral sand, it has the disadvantage that ammonia must be used and that heating equipment must be installed. It takes a long time to immerse sand for 24 hours or more to generate silver carbonate on the surface of coral sand, and depending on the type of reducing agent, silver carbonate can reduce only black silver oxide. .

That is, this physical impregnation method requires a heating facility and requires a high cost for this heat source, and there is a problem of odor during heating. The chemical impregnation method involves a reaction between coral sand and a silver nitrate solution. It requires a long time, and depending on the type of reducing agent, it cannot completely reduce silver.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a method for producing a sterilizing purification agent which solves the disadvantages and problems of the conventional method, which comprises adding a silver nitrate solution to coral sand, Ascorbic acid solution is added to the above to impregnate silver oxide on the surface of coral sand, and then hydrogen peroxide solution is added to this to make silver oxide metallic silver.

That is, as a result of various studies on the method of easily adhering silver to coral sand, the present inventors have found that when a nitrate solution is added to coral sand and an ascorbic acid solution is added thereto, the surface of the coral sand is instantaneously added. Since black silver oxide is attached to, silver oxide was added to this silver oxide, and it was found that this silver oxide was reduced to silver and this silver was attached to coral sand. The present invention has been completed by confirming that the desired sterilizing cleaning agent can be easily obtained. This will be described in more detail below.

[0007]

In the method for producing the sterilizing agent according to the present invention, the silver nitrate solution is first added to the coral sand, which is added to the coral sand while stirring the silver nitrate solution in which silver nitrate is dissolved in water. Good. The coral sand to which this silver nitrate solution was added does not need to be left for a long time, and when the ascorbic acid solution was added to it, this ascorbic acid was a substance with a strong reducing power, so that it immediately reacted with silver nitrate. Since silver nitrate is silver oxide (Ag ₂ O), the silver oxide formed here is attached to the surface of the coral sand.

Then, when hydrogen peroxide is added thereto, the hydrogen peroxide also has a reducing property. Therefore, this silver oxide is converted to the following formula Ag ₂ O + H ₂ O. ₂ → 2Ag + H ₂ O + O ₂ ↑ is reduced to silver, and this silver is attached to the surface of the coral sand to serve as a sterilizing purification agent, which eliminates the need for heating equipment and therefore the cost of the heat source. Without the above disadvantage, and without the problem of odor such as ammonia odor,
The advantage is that the desired sterilizing purification agent can be obtained easily in a short time and at low cost. However, according to this, since coral sand is porous, the part where silver does not adhere is given. Calcium and other minerals are present in the product, and a sterilizing purifying agent is provided in which calcium and other minerals are eluted to become weakly alkaline.

[0009]

EXAMPLES Next, examples and comparative examples of the present invention will be described. Example 1 To 100 g of coral sand (CaCO ₃ ), a silver nitrate solution prepared by dissolving 2.4 g of silver nitrate in 70 ml of water was added with stirring, and then 15 ml of a solution of 1 g of ascorbic acid dissolved in water was added with stirring. As a result, silver nitrate instantly became black silver oxide and was attached to the coral sand.

Next, when 15 ml of hydrogen peroxide solution having a concentration of 5% was added to and mixed with this coral sand while stirring, silver oxide was instantly reduced to silver and attached to the surface of the coral sand. dried pulled up from the reactor, nitrate (NO ₃ ^-) is washed with water until 5ppm or less, and dried to give sterilizing purifying agent are as shown in Table 1, impregnation of silver is below the When the number of Escherichia coli for each sensitization time for 50 ml of Escherichia coli test bacterial solution was examined using this sterilizing agent, the results shown in Table 2 below were obtained. When the number of mixed bacteria for each sensitization time for 50 ml of the mixed bacterial solution of various bacteria was examined, the results shown in Table 3 below were obtained. The control examples in Tables 2 and 3 show the results of the comparative examples in which this purifying agent was not used.

Example 2 A silver nitrate solution prepared by dissolving 12 g of silver nitrate in 350 ml of water was added to 500 g of coral sand (CaCO ₃ ) with stirring, and then 50 ml of a solution of 5 g of ascorbic acid in water was mixed with stirring. Then, silver nitrate instantly became black silver oxide and was impregnated on the coral sand. Then, when 50 ml of hydrogen peroxide solution having a concentration of 5% was mixed with stirring, silver oxide was reduced to silver and became coral sand. Since it was impregnated, it was dehydrated, washed with water and dried in the same manner as in Example 1. As a result, a sterilizing purifying agent having an impregnation ratio of silver as shown in Table 1 was obtained.

[0012]

[Table 1]

[Table 2]

[Table 3]

[0013]

INDUSTRIAL APPLICABILITY The present invention relates to a method for producing a sterilizing purifying agent in which coral sand is impregnated with silver. According to this method, silver oxide is instantly impregnated onto the surface of coral sand from a silver nitrate solution, and this oxidation is carried out. Since silver is instantly converted to silver, there is an advantage that a sterilizing purification agent in which silver is attached to the surface of coral sand in an amount close to the theoretical value can be obtained easily and at low cost.

Claims (1)

[Claims] 1. A silver nitrate solution is added to coral sand, an ascorbic acid solution is added thereto to attach silver oxide to the surface of the coral sand, and then hydrogen peroxide water is added thereto to add silver oxide. A method for producing a sterilizing purification agent, which comprises using metallic silver.