JPS5823160B2 - water treatment agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel water treatment agent, and particularly to a water treatment agent that exhibits excellent effects as a sludge dewatering agent.

Dirt generated when treating sewage or organic wastewater.

Sludge has poor dehydration properties and contains a lot of water, so it requires a lot of energy even if it is incinerated. Therefore, it is necessary to remove as much water as possible during the sludge dewatering process. Dehydrating agents are being researched and used.

For example, an inorganic flocculant such as polyaluminum chloride, aluminum sulfate, or ferric chloride is used in combination with lime as a dehydration aid.

However, this method generally requires a large amount of added drug;
Furthermore, when incinerated, it has poor flammability, requires a large amount of auxiliary fuel, and has a considerable ash content.

There are drawbacks such as the generation of large quantities.

Therefore, in recent years, various organic flocculants have been adopted in place of these inorganic flocculants.

However, although these organic flocculants are excellent in flocculating sludge, the flocs tend to collapse during the subsequent filtration treatment, clogging the furnace material, and in fact, sufficient filtration cannot be achieved with organic flocculants alone. Improving the dehydration rate is not easy.

For this reason, as a method of improving the dehydration rate of these organic flocculants, methods of adding and mixing sawdust, rice husk charcoal, etc. have been seen here and there, but at present, sufficient dehydration performance cannot be expected.

Therefore, the present inventors conducted research to obtain a dehydrating agent that has even better dehydrating properties without sacrificing the advantage that the method of using these sawdust and rice husks as a dehydrating aid facilitates the incineration of sludge cake. As a result, the present invention has been completed.

That is, the present invention relates to a water treatment agent obtained by graft polymerizing a water-soluble vinyl monomer to sawdust or rice husk.

The water-soluble vinyl hexamers used in the present invention include dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, their hydrochlorides, sulfates,
Examples include tertiary salts such as acetate, quaternary salts quaternized with methyl chloride, dimethyl sulfate or diethyl sulfate, acrylic acid, methacrylic acid or ester compounds thereof, acrylamide, methacrylamide, and the like.

On the other hand, the sawdust and rice husk used in the present invention are discarded as industrial waste, but it is desirable to use them after pulverization, and the degree of pulverization is not particularly limited, but it is preferably about 20 to 500 mesh.

In another embodiment, these may be used after being smoldered and carbonized.

The water treatment agent of the present invention is obtained by graft polymerizing a water-soluble vinyl monomer to the above-mentioned sawdust and rice husk, but the most surprising thing in the production of the water treatment agent of the present invention is that the sawdust or rice husk is Alternatively, graft polymerization can be carried out by simply mixing these smoked materials and leaving them to stand.

Normally, a catalyst, ultraviolet light, or radiation is used as a polymerization means to polymerize a water-soluble vinyl monomer, but in the present invention, these methods are not necessary and the water-soluble vinyl monomer is grafted onto sawdust or rice husk. Can be polymerized.

From this fact, it is presumed that sawdust or rice husk has some kind of radical generating function, but it is not certain.

For this reason, the water treatment agent of the present invention can be produced at a very low cost, but in order to increase the polymerization rate or take into consideration the use of existing equipment, it is possible to prevent the use of catalysts, ultraviolet rays, and radiation during polymerization. isn't it.

When using such a polymerization method, a well-known polymerization method may be followed, and there are no particular considerations.

Therefore, in the case where graft polymerization is carried out simply by mixing sawdust or rice husk with a water-soluble vinyl monomer, the appropriate concentration of mokummer is generally in the range of 20 to 90 parts.

Although there are no restrictions on the amount of sawdust or rice husk added, the degree of polymerization generally decreases as the ratio of sawdust or rice husk added to the monomer increases.

The reaction temperature is preferably 20 to 80°C.

The effects of the water treatment agent of the present invention will now be specifically explained as follows.

Specific Example 1 13:4 g of acrylamide, dimethylaminoethyl methacrylate methyl chloride salt, 27.
2&, 10 g of ion-exchanged water was taken and dissolved with stirring while purging with nitrogen, and the liquid temperature was set at 60°C.

Next, add 100g of sawdust of 200 mesh or less,
After stirring, polymerization was carried out for 10 hours.

This polymer was thoroughly washed with water at 60° C. and dried under reduced pressure to obtain 133 g of a graft polymer.

Next, this graft polymer was used to test the dewaterability of activated surplus sludge (suspended solid content: 2.3% by weight, pH: 7.4).

500rrL of the above sludge was taken into a beaker, and the graft polymer 2 was added to this suspended solid content (hereinafter abbreviated as SS).
The 1st suspension water is added to the 1st suspension water in terms of the polymer in the graft polymer.
Add in the proportion shown in the figure and add water to bring the total amount to 600.
After stirring at 20 Or, p, m for 10 minutes,
The Nutsche test was conducted under the conditions shown below.

[Nutsche test conditions]

Degree of vacuum: 400 mmHg Filtration area: 95c111 Furnace material: Toyo Roshi/I6.5A As a comparative example, the product name "Bless" manufactured by Stockhausen (Germany) is an acrylamide polymer that has excellent dehydration properties in place of Grarad polymer. Thor 4
A similar test was conducted using 33K'' and sawdust in the same ratio as the water treatment agent of the present invention, that is, at a ratio of 3:10.

The results are shown in FIG.

<Analytical values for Brestall 433> 0.5 coefficient Aqueous solution viscosity * 190Cp Cationation rate 41 coefficient *Viscosity is BH type viscometer / 1620-ter, 30r, p,
The measurement was carried out at 30°C.

As is clear from Figure 1, the water treatment agent of the present invention can greatly increase the dewatering filtration rate with a smaller amount added than in the conventional method, that is, when a polymer flocculant and sawdust, etc. are used separately. I can do it.

. The advantages of the water treatment agent of the present invention are as follows: (1) Good filtration and dehydration properties and high filtration speed.

◎The moisture content of the dehydrated cake decreases significantly.

◎Easy to incinerate. etc. can be mentioned.

Examples of the present invention are listed below and will be further explained.

Example 1 40 g of dimethylaminoethyl methacrylate methyl chloride salt and 10 g of ion-exchanged water were placed in a reaction vessel with a capacity of 500 ml and equipped with a stirrer, a nitrogen inlet tube, and a thermometer, and dissolved with stirring while purging with nitrogen. It was set at ℃.

Next, add 100g of rice husks of 300 mesh or less,
After stirring, polymerization was carried out for 10 hours.

This polymer was thoroughly washed with water at 60°C and dried under reduced pressure to obtain 120 g of a graft polymer.

When 37 ml of this graft polymer 2-ply 1-suspended water was added to 500 ml of activated surplus sludge used in Example 1 and a dewatering test was conducted, the filtration rate was 3.4°·kl/m''.
It was hr.

As a comparative example, the product name “Breastall 444K” (0
, 5% aqueous solution dust 550 cp1 cationization rate 100
%) The same ratio of rice hulls and the water treatment agent of the present invention, i.e. 3
: When used together at a ratio of 10, it is 0.7 kl/
It was m, hr.

) Example 2 In the reaction vessel used in Example 1, acrylamide 27.9 &
, 19.7 g of sodium acrylate (80% aqueous solution by weight),
10 g of ion-exchanged water was taken and dissolved with stirring while purging with nitrogen, and the liquid temperature was set at 60°C.

Next, add less than 300 mesh of sawdust,
After stirring, polymerization was carried out for 20 hours.

This polymer was thoroughly washed with water at 60° C. and dried under reduced pressure to obtain 132 g of a graft polymer.

This graft polymer and polyaluminum chloride (A120
A test was conducted in which oil-containing wastewater (oil content: 677 ppm, SS: 323 ppm) was treated using the following method.

200ml of polyaluminum chloride to 500ml of the above oil-containing wastewater
After adding 0 ppm and mixing for 2 minutes, 2.5 ml of the above graft polymer 2 weight suspension was further added and mixed.

Next, the generated scum was removed and the oil content was 8 ppm, SS6
．． 6 ppm treated water was obtained.

As a comparative example, a polymer flocculant (molecular weight 10 million, anionization ratio 30) produced using acrylamide and sodium acrylate instead of the graft polymer was used in combination with sawdust at a weight ratio of 3:10. As a result of the same test,
Treated water with an oil content of 26 ppm and 8832.5 ppm was obtained.

Example 3 Polymerization was carried out in the same manner as in Example 2, using rice husk charcoal instead of sawdust, to obtain 124 g of a graft polymer.

5.5 ml of this graft polymer 2 weight suspension was added and mixed with 500 ml of oil-containing wastewater used in Example 2 and treated in the same manner, resulting in an oil content of 71)I)m)S88.2
ppm treated water was obtained.

Example 4゜Acrylamide 13.4g1 was added to the reactor used in Example 1.
Dimethylamine methyl methacrylate methyl chloride salt 27
2 g and 10 g of ion-exchanged water were taken and dissolved with stirring while purging with nitrogen, and the liquid temperature was set at 60°C.

Next, 100g of rice husks weighing less than 200 medus and 2.2
-Azobis(2-amidinopropane) dihydrochloride 1% aqueous solution (2.0 rnl) was added, stirred, and then polymerized for 10 hours.

This polymer was thoroughly washed with water at 60°C and dried under reduced pressure to obtain graft polymer 128.

Specific example 1: 43 ml of this graft polymer 2 weight suspension
When a similar dewatering test was carried out by adding it to 500ml of activated surplus sludge used in
' It was m・hr.

As a comparative example, when the above-mentioned "Breastall 433K" and rice hulls were used together at a weight ratio of 3:10, the yield was 0.9 kl/m"·hr.

[Brief explanation of drawings]

FIG. 1 shows the experimental results of a specific example.

Claims (1)

[Claims] 1. A water treatment agent obtained by graft polymerizing a water-soluble vinyl monomer to sawdust or rice husk. “