JPS5838230B2 - Deodorizing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for deodorizing toilets, human waste treatment plants, industrial waste, and other odorous substances, and particularly relates to a method for deodorizing toilets, human waste treatment plants, industrial waste, and other odorous substances, and particularly relates to a method for deodorizing toilets, human waste treatment plants, industrial waste, and other odorous substances. The purpose is to provide an effective method for deodorizing objects.

Traditionally, silica gel, activated carbon, etc. made of solid fine particles have been widely used to deodorize odorous substances, but these methods rely on gaseous odorous compounds being captured by the deodorizing agent. It has been extremely difficult to deodorize extremely strong odors, to deodorize a large amount of odorous substances, to deodorize them quickly, etc. using conventional methods.

As a result of various studies aimed at improving the shortcomings of these conventional methods, the present inventors discovered that odor-bearing substances can be deodorized very effectively by incorporating a special silica sol or alumina sol, and have completed the present invention. did.

The present invention has a specific surface area of at least 20 m2/. !
i' or more, and is a deodorizing method characterized by including an active silica sol and/or alumina sol in a odorous substance using substantially non-agglomerated water and/or a water-soluble organic solvent as a dispersion medium.

An object of the present invention is to provide a method for rapidly deodorizing even a large amount of odoriferous substances in an extremely short period of time.

Unlike conventional methods that use solid deodorizers such as silica gel and activated carbon, the method of the present invention allows substantially unagglomerated silica or alumina particles with a high specific surface area to come into direct contact with the odor source as a liquid dispersion. By adsorbing substances and, in some cases, coating them, and in the case of odorous substances in liquids, in addition to these, it also has the effect of increasing the particle size of the liquid and reducing the diffusion rate of odorous substances. It is something.

In the present invention, the specific surface area of the silica sol and/or alumina sol is required to be 20 m'/g or more because this value is the lower limit for the deodorizing effect when added in liquid form, and the preferable range is 100 m'/g. This is due to the necessity.

Further, a more preferable range is 250 m2/g for silica sol.
The above is 110 rrL2/g or more for alumina sol, and a liquid silica sol or alumina sol with this activity shows a deodorizing effect in a larger amount and more quickly.

Activated silica sol that is not substantially agglomerated is referred to as the product name “
A typical example is the one commercially available as "Snowtex" (Nissan Kagaku K.K., registered trademark), but silica liquid obtained by removing the alkaline content from water glass is also particularly effective.

Similarly, as alumina sol, the product name is "Alumina sol"
(manufactured by Nissan Chemical KK) is commercially available.

Water is generally used as the dispersion medium in all cases, but methanol, ethanol, isopropanol, polyhydric alcohols, tetrahydrofuran, dimethylformamide, etc. alone or a mixture of these and water may also be used as the dispersion medium.

Among these, the specific surface area is 250 m27 g.
In the above, activated silica sol using water as a dispersion medium shows the most excellent effect.

The odoriferous substances targeted by the present invention include human waste, sludge, organic waste, etc., and the effect on human waste is particularly remarkable.

In order to carry out the present invention, the silica sol and/or alumina sol, etc. may be added to the S-odorous substance as is, or may be mixed and kneaded after addition, or may be mixed with other additives in advance,
This can be done by adding the odor to the odorous substance or adding the odor to the sol.

Addition can be carried out by adding at once, by spraying, or the like.

An addition method that forms a coating layer on the surface of the odorous substance is also suitable.

It is also possible to deodorize the sol by bubbling odor gas into the sol.

The concentration and amount added of activated silica sol and alumina sol vary depending on the target and are not constant, but silica sol with a concentration of 2% or more as SiO2 and 3% as Al203
An alumina sol having a concentration of at least 10% is preferable.

The specific surface area of the silica sol, alumina sol, etc. used in the present invention is determined by using the alumina sol as it is, and the silica sol by adjusting the pH to 3 with HNO3 and completely drying it in a dryer at 80°C or lower to form a powder of approximately 300 mesh. After that, B. E. T. Measured by method.

This will be explained below with reference to examples.

Example 1 All of the five normal ordained monks acknowledged that the toilet in a private residence had an odor.

The toilet tank has a specific surface area of 620 g/m2,
Aqueous silica sol 30 (Bi
When ' was added uniformly in the form of raindrops, 2 out of 5 people acknowledged that the odor was almost gone after 5 minutes, and all of them acknowledged that the odor had almost disappeared after 10 minutes.

On the other hand, as a comparative example, the specific surface area is 9 1 0 m27 &? When 40g of silica gel powder containing in29 5.0% was added in the same manner as above and the degree of odor was determined, 5 out of 5 people found that the odor had not decreased even after 10 minutes.
After 60 minutes, 1 out of 5 people admitted that the odor had decreased slightly.

As shown in the results, silica gel did not have the same quick effect and deodorizing ability as the above-mentioned silica gel.

Example 2 S as a silica sol with a specific surface area of 210 m2/g
A test was conducted in exactly the same manner as in Example 1 except that 200 g of in21 5 wt % aqueous silica sol was used.
After 10 minutes, 1 out of 5 people admitted that after 30 minutes, all 5 people admitted that the odor had almost completely disappeared.

Example 3 AI203 with a specific surface area of 130rrL2/g as a substitute for silica sol 4. Example 1 except that 500 g of alumina sol was used as a dispersion medium, and the dispersion medium was a mixed liquid of 5 wt % and a water: ethylene glycol weight ratio of 95:5.
When a test was conducted in the same manner as above, 1 out of 5 people admitted that the odor had almost disappeared after 10 minutes, and 3 out of 5 people after 30 minutes.

Example 4 A foul-smelling wastewater sludge (solid content approximately 5 parts) accumulated in the lower layer of a sedimentation tank was taken out, and the specific surface area was 5 parts based on this IOOKP.
S102 5.2wt% at 50 m2/g
Silica Sol 30K2 was added and stirred for 5 minutes using a stirrer.The odor gradually decreased over the course of 1 hour, and after 1 day it was noticed that the odor had decreased considerably.

Example 5 Al034.5wt with specific surface area 130 m2/g
%, and the weight ratio of water: ethylene glycol is 9
Alumina sol 251 using a 5:5 mixture as a dispersion medium has a specific surface area of 180 m2/g and a concentration of 26.3 wt% Sin.
The test was carried out in the same manner as in Example 1 except that a mixture of 200 g of aqueous silica sol was used. After 10 minutes, 1 out of 5 people said that there was no odor at all, and after 30 minutes, 3 out of 5 people said that there was almost no odor. I admitted that I had run out of time.

Claims (1)

[Claims] 1. An active silica sol and/or alumina sol having a specific surface area of at least 20 m'/9 or more and containing substantially non-agglomerated water and/or a water-soluble organic solvent as a dispersion medium. How to remove odors.