JPH01128905A - Molded composition for water treatment - Google Patents

Abstract

PURPOSE:To obtain the title composition suitable for sterilizing especially waste water, having increased elution rate and uniform solubility without swelling and collapsing, containing trichloroisocyanuric acid and orthoboric acid having specific particle diameter in a specific ratio. CONSTITUTION:The titled composition contains trichloroisocyanuric acid having 400-3,000mu average particle diameter and orthoboric acid having 100-2,000mu in the weight ratio of 100:8-60 (preferably 100:10-50) and subjected to pressure molding under 100-1,000kg/cm<2>. The composition is suitable for sterilizing waste water of septic tank, ordinary drain or industrial drain in flow channel thereof, neither swells nor collapses even in immersion in water, gradually dissolves from the surface and shows uniform solubility. The composition will not evolve an irritating gas such as chlorine or nitrogen chloride during preservation, especially during use in a wet state.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a water treatment tablet that sterilizes water by releasing active chlorine. More specifically, it relates to a molding composition for water treatment containing trichloroisocyanuric acid as a main component, which is suitable for sterilizing wastewater such as septic tank wastewater, general wastewater, industrial wastewater, etc. and has excellent solubility. It is.

(Prior Art and Problems) Conventionally, highly bleached powder that releases active chlorine, dichloroisocyanuric acid or its salts, trichloroisocyanuric acid, etc. have been widely used for water sterilization, membrane thinning, etc. Highly bleached powder has high solubility, but is highly hygroscopic and has low storage stability. It also has the disadvantage of containing large amounts of calcium hydroxide and calcium carbonate, which are poorly soluble in water. Potassium dichloroisocyanurate and sodium dichloroisocyanurate have high solubility in water and have higher storage stability than highly bleached powder, but they are expensive to produce and have a lower effective chlorine content than trichloroisocyanuric acid, which will be described later. Also, there is a drawback that moldability is low.

Trichloroisocyanuric acid (hereinafter referred to as TCCA) has an effective chlorine content of 90%, which is the highest among solid chlorine agents, and is a solid chlorine agent with excellent storage stability and easy handling. Therefore, it can be easily used for purposes such as sterilization, bleaching, oxidation, decolorization, and deodorization, so it can be used as a water treatment agent for sterilization, membrane thinning, and various purposes of swimming pool water, septic tank wastewater, other circulating water, water storage factory wastewater, etc. It is widely used as However, T
CCA has the drawbacks of low solubility in water and slow dissolution rate. The solubility of TCCA in water is 1.2% at a water temperature of 20°C, but when the water temperature is low, the -layer solubility decreases, and it cannot be sufficiently effective as a water treatment agent in winter. There is. Despite this low solubility, TCCA is widely used as a disinfectant for pool water and as a treatment agent for wastewater. This is T
This is because CCA has advantages such as being easy to handle.
Even if the dissolution rate is slow and it dissolves gradually, there is no problem in sterilizing stagnant water systems such as pools.

Tablets made by adding a small amount of orthoboric acid powder to TCCA as a lubricant or mold release agent are commercially available for wastewater treatment, but these tablets are slightly less active chlorine elution than TCCA tablets alone. Although it is large, the elution of active chlorine is delayed at low water temperatures in winter, making it insufficient.

Several suggestions have been made to increase the solubility of TCCA. For example, in Japanese Patent Application Laid-open No. 51-139628, TC
It has been proposed that 1-lium dichloroisocyanurate or the like be added to CA and then compressed to form tablets. Furthermore, JP-A-54-160730 proposes adding an alkali metal salt of isocyanuric acid to TCCA and then molding the mixture into tablets. Tablets according to these proposals are used for sterilizing pool water, etc., but these swell in water and immediately disperse, resulting in a high dissolution rate of active chlorine.

In other words, molded products such as swollen and dispersed granules and tablets, which are conventional measures against the low solubility of TCCA, are intended to supply active chlorine to the retained water system in a short period of time; It can be said that this has been achieved.

However, depending on these molded products, the purpose of constantly supplying active chlorine at a substantially constant concentration for sterilizing running water such as wastewater cannot be achieved.

For sterilization of running water, unlike when sterilizing stagnant water systems such as pool water and stored water, it is necessary to elute active chlorine through gradual dissolution from the surface of the molded product without the molded product swelling or dispersing. There is.

Of course, the solubility of TCCA must be increased.

In addition, in Tokkosho, J9-24974, 'j
TCCA compositions have been proposed in which CCA is rapidly dissolved. The composition is a composition obtained by mixing an alkali metal carbonate with a mixture of TC, CA and isocyanuric acid or an alkali metal salt of cyanuric acid, or a composition having an absolute density of 2.
．． It is a granular composition of 0 to 2.5 g/cm'. This composition has the following drawbacks.

(1) It absorbs moisture from the outside air, which not only increases the loss of available chlorine during storage, but also generates carbon dioxide, which poses a risk of rupturing the sealed packaging container.

(2) Especially during use, generation of harmful gases such as chlorine gas and chloramine gas is accelerated in water or when wet.

(3) The dissolution rate is too high because the granules swell, disintegrate, and are further dispersed in water. This is the biggest drawback.

All of these drawbacks are considered to be due to the inclusion of alkali metal carbonates. The granular composition disclosed in this publication has a relatively small diameter and is subject to swelling, disintegration, and dispersion. Even tablets formed into tablets immediately disintegrate and disperse in water, making it impossible to adjust the dissolution rate.

Further, although Japanese Patent Publication No. 39-24974 describes adding alkali metal phosphates, borates, silicates, etc. to the composition, the ratio of raw salt In to TCCA is extremely large. Moreover, the above-mentioned drawbacks cannot be overcome.

Japanese Patent Application Laid-Open No. 58-5990, which the present inventors have already filed
Publication No. 4 describes trichloroisocyanuric acid and isocyanuric acid, alkali metal phosphates, silicates or borates,
Alternatively, a molding composition for water treatment made of an alkaline earth metal oxide has been described, but although this molding composition exhibits uniform solubility and has an improved dissolution rate compared to conventional methods, the formulation becomes non-uniform. There is a problem with tablets breaking in water.

In this way, it has a high dissolution rate and swells even when immersed in water.
There is no molded product for water treatment whose main component is TCCA that gradually dissolves from the surface without disintegrating and exhibits uniform solubility.

The object of the present invention is to provide a molding composition for water treatment that can increase the dissolution rate without swelling or disintegrating when immersed in water, especially running water, exhibits uniform solubility, and can supply the active chlorine concentration necessary for sterilization. Our goal is to provide the following.

Another object of the present invention is to provide water treatment based on trichloroisocyanuric acid that is stable and safe and does not generate irritating gases such as chlorine and nitrogen chloride during storage and use, especially when used in humid conditions. The aim is to provide tablets for

(Means for Solving the Problems) As a result of studying tablets formed by adding orthoboric acid to TCCA, the present inventors found that the diameters of the particles of TCCA and orthoboric acid used during tableting exceeded a certain level. The present invention was completed based on the discovery that the above-mentioned problems could be solved by using a lubricant and using a larger amount of orthoboric acid than is normally used as a lubricant (5% or less).

That is, the present invention provides a molding composition for water treatment comprising trichloroisocyanuric acid and orthoboric acid with an average particle size of 4.
The present invention relates to a molding composition for water treatment, characterized in that it contains 8 to 60 parts by weight of orthoboric acid having an average particle diameter of 100 to 2000 μm per 100 parts by weight of trichloroisocyanuric acid having an average particle size of 00 to 3000 μm, and is pressurized.

If the average particle size of trichloroisocyanuric acid is less than 400 μm or the average particle size of orthoboric acid is less than 100 μm, the dissolution rate of the tablet will be extremely slow, and the elution of active chlorine from the molded product will be significantly reduced.

The average particle size of trichloroisocyanuric acid is 400-30
00μ is preferable, and the average particle diameter of orthoboric acid is 100~
2000μ is preferred. The average particle size of trichloroisocyanuric acid is 3000μ, and the particle size of orthoboric acid is 200μ.
If it exceeds 0μ, the resulting molded product will be non-uniform and the solubility of the molded product will not be constant, which is not preferable. The blending amount of orthoboric acid is 8 parts per 100 parts by weight of trichloroisocyanuric acid.
-60 parts by weight, preferably 10-50 parts by weight.

Pressure molding to form the water treatment molding composition of the present invention is pressure molding using a conventional dry or wet tabletting machine or other molding machine to form dosage forms such as fine particles, granules, pills, and tablets. means to do so.

The molding pressure is 100 to 1000 kg/cm".100
If it is less than 1000 kg/cm, it will easily disintegrate in water.
/cm", it is difficult to tablet. The size of the molded product is usually 20-100 mmφ, and the density is 1.5-1.9 g.
/c~3. If the density is less than 1.5 g/cm', it will easily disintegrate in water, and if it exceeds 1.9 g/cm', it will be difficult to tablet.

The molding composition of the invention can be used in any manner for water treatment. The molding composition of the present invention exhibits particularly excellent effects when used for treating running water.

That is, when placed immersed in water in the flow path of septic tank wastewater to be sterilized, other circulating water, factory wastewater, etc., the molding composition of the present invention does not disintegrate, and has a considerably high dissolution rate of active chlorine. Furthermore, active chlorine can be supplied to running water while maintaining its dissolution rate approximately constant for a long period of time. The amount of active chlorine released varies depending on the conditions of the flowing water and can be adjusted by the amount of the molding composition of the present invention immersed in the flowing water, but in general, the amount required for sterilization depends on the concentration of active chlorine in the flowing water. The amount is maintained at 5 to 15 ppm.

The molding composition of the present invention will be explained below along with Examples and Comparative Examples, but the molding composition of the present invention is not limited to these Examples.

First, a method for molding the molding composition of the present invention used in Examples,
The method for measuring the dissolution rate will be described, and Table 1 shows the particle size and water content of the raw materials used to manufacture the tablets.

[Forming method] After filling a mortar with a diameter of 35 mm with 30 g of the composition obtained by uniformly mixing the raw materials shown in Table 1, a pestle was placed on top of the composition, and a surface pressure of about 400 kg/cm2 was applied using a hydraulic press. Pressure is applied and compression molded to a diameter of approximately 35 mmφ and a thickness of 1 mm.
It was made into a tablet with a diameter of 9 mm and a density of 1.62 g/cm''.

[Method for measuring dissolution rate]

1 in an aquarium with length, width, and depth of 400 x 400 x 100 mm
Tap water (groundwater) at 7±1°C was continuously passed through at a rate of 31/min. The liquid level was kept constant by overflow.

4 meshes at a depth of 50mm below the liquid level (mesh opening 4.7m)
m) A large stainless steel wire gauze is provided, the tablets obtained by the above molding method are placed on it, and after 8 hours of water flow, the weight of the remaining tablets after drying with hot air is calculated. The active chlorine concentration was measured by the ortho-tolidine method.

Table-1 Particle size of tablet raw materials Examples 1 to 5 and Comparative Examples 1 to 11 Raw materials for trichloroisocyanuric acid (C) and (d) and orthoboric acid (c) and (d) shown in Table-1. The raw materials were compressed into tablets using the above-mentioned molding method, and the dissolved amount and active chlorine concentration were measured. The results are shown in Table-2. As shown in the evaluation results in Table 2, the molding composition of the present invention has an increased melting rate, and -i is the active chlorine concentration necessary for sterilizing running water.
~15 ppm.

(Margin below)

Claims (1)

[Claims] In a molding composition for water treatment consisting of trichloroisocyanuric acid and orthoboric acid, the average particle size is 400 to 3000.
1. A molding composition for water treatment, comprising 8 to 60 parts by weight of orthoboric acid having an average particle diameter of 100 to 2,000 μ per 100 parts by weight of trichloroisocyanuric acid having a particle size of 100 to 2,000 μ and pressurized.