JPS6178499A - Sludge dehydrating agent - Google Patents

Abstract

PURPOSE:To attain the uniformization of solubility, by containing a water-soluble powdery deodorant, a powdery high-molecular flocculant and a powdery cationic surfactant. CONSTITUTION:A water-soluble deodorant containing glyoxal, a powdery cationic surfactant such as benzalkonium chloride and a powdery high-molecular flocculant such as N-dialkylaminoalkyl (meth)acrylate are compounded in a wt. ratio of about 0.2-4:0.01-0.4:10.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a sludge dewatering agent.

For more information, see Powder stains containing water-soluble powder deodorizers. This relates to mud dehydrating agents.

^ [Problems to be solved by the prior art and the invention] Polymer flocculants are used as dehydrating agents for sewage and human waste @ j94 sludge and other organic sludge; When dehydrated, the sludge had a bad odor (not only caused environmental pollution but also made workability worse).

In order to solve this problem, it has been proposed to incorporate a deodorant into the sludge dewatering agent. For example, JP-A-56-76
No. 96 discloses a technical idea of blending an oily deodorant and a surfactant with a powdered polymer flocculant.

However, although this method of using oil-based deodorizers has excellent performance, when added to sludge, the deodorizer floats or settles and separates, and the deodorizing effect cannot be effectively achieved. was there. To prevent this, an emulsifier is added, but it is not always dispersed uniformly, resulting in a stable deodorizing effect! f. Yes, it was just one step.

On the other hand, if the deodorant is composed of a water-bathable base, it will not separate during dissolution (it is thought that the deodorizing effect will be more efficient).

For example, Japanese patent publication No. 50-3087 discloses a composition in which a polymer flocculant is dissolved in wood vinegar, which is a water-soluble deodorant.

However, with this alone, the deodorant migrates to the water side and is washed away, so it lacks sustainability and is unsuitable as a sludge dehydrating agent. It will no longer be possible to take advantage of its characteristics (such as ease of transportation and low logistics costs).

Historically, JP-A-58-112098 discloses a method in which a water-soluble deodorant is held in an insoluble carrier, and this carrier is dehydrated by adding sludge VC.

However, even with this method, when bathing island molecules and aggregating agents, the carrier separates and precipitates or floats, which not only makes it difficult to dissolve uniformly, but also clogs the drug injection piping. This was causing trouble for the staff, etc.

As described above, the sludge dehydrating agents including water-soluble deodorizers that have been proposed so far each have their own characteristics, and are far from being put to practical use.

[Means for resolving gaps in studying]

This invention was made in order to overcome the problems of the prior art, and includes a water-soluble powder deodorant obtained by powdering glyoxal, a powdered polymer flocculant, and a powdered cationic powder. It is a sludge dewatering agent containing a surfactant.

In order to make a water-bathable deodorant containing glyoxal, it is necessary to select a water-bathable medium for powdering glyoxal. Examples of water-soluble media include reactive compounds and carriers that release glyoxal again after dissolution, but especially ethylene glycol, polyvinyl alcohol, starch, and carboxymethyl cellulose (
CMC)) l! ! In this case, ethylene glycol is a reactive compound and reacts with glyoxal to form dihydroxydioxane. The remainder acts as a carrier. Both are substances that release glyoxal when they become a bath solution.

As a powdering method, add a predetermined amount of glyoxal to an aqueous solution containing a predetermined amount of a water-soluble medium, stir thoroughly, and react.
After being impregnated or supported, it may be powdered.

The powdered polymer flocculant used in this invention is preferably a cationic one, such as a homopolymer of N-dialkylaminoalkyl (meth)acrylate, a copolymer with other vinyl monomers, an acid adduct thereof, or Examples include quaternized products, Mannich modified products of polyacrylamide, Hofmann decomposition products, and chitosan. Will you use one of these when implementing it? It may be used alone or in combination of two or more bars.

The composition containing only the powdered deodorizing agent and powdered polymer flocculant described above has excellent immediate effect when added to sludge in the form of an aqueous solution, but as with the prior art described above, deodorizing is inevitable. The agent migrates into water, resulting in poor long-lasting effects. Therefore, in this invention, by further blending a specific surfactant which itself has a deodorizing effect, the deodorizing agent leaks to the water side and 7'cvk also reacts with the sludge and is adsorbed by the sludge. Thanks to the action of the surfactant, we were able to maintain the deodorizing effect even after that.

That is, in this invention, powdered cationic surfactant?
Further blending is an essential requirement.

As the powdered cationic surfactant, benzalkonium chloride represented by the following formula is suitable.

Hs R#'X alkyl having 8 to 18 carbon atoms Represents a mixture of groups.

This surfactant has a great deodorizing effect when used alone, but when used in combination with glyoxalt as in this invention, it has a much better deodorizing effect in terms of immediate effect and long-lasting effect than when each is used alone. Demonstrate.

This benzalkonium chloride is commercially available and readily available.

The present inventors used various surfactants themselves in order to exert a sustained deodorizing effect, but the anionic surfactant hg
Both J-magnetic and nonionic surfactants provided a significant difference in performance compared to the cationic surfactants used in this invention.

The blending ratio of the powder deodorant, powder cationic surfactant, and powder polymer flocculant is not particularly limited, but in practice it is 0.2 to 4:0.01 to 0.4:10 (weight ratio). degree.

As for the blending method, it is preferable to mix the deodorant and the surfactant and then mix the powdered polymer flocculant into this mixture, but the king may be mixed at the same time.

The sludge to which the sludge dewatering agent of this invention is applied is sewage,
Human waste and sludge discharged from various organic industrial wastewater treatment facilities, such as 1-, 2-, and 3-year sludge of human waste, anaerobic digested sludge, and mixtures thereof, human waste septic tank sludge, raw sewage sludge, digested sludge, and these Examples include mixed sludge from industrial wastewater, and surplus sludge from activated sludge treatment of industrial wastewater.

In addition, among these sludges, for sludge with a high pH such as digested sludge, it is recommended to add 1° of powdered acid to the composition of this invention to lower the pH of the sludge. Ru. Powdered acids used for this purpose include sodium hydrogen sulfate, sodium dihydrogen phosphate, borium, sulfamic acid, maleic acid, malic acid, malonic acid, conolic acid, tartaric acid, oxalic acid, citric acid, and fumaric acid. Illustrated.

The sludge dehydrating agent blended in this manner may be dissolved in water and added to the target sludge. All of the sludge dewatering agents of this invention are water-soluble powders, and when sufficiently stirred, they dissolve uniformly. Then, this solution is added to the sludge to be treated on a fixed plate, mixed and stirred to form flocs, and dehydrated using a known dehydrator such as a filter press, belt press, or centrifugal dehydrator.

[For production]

When the sludge dewatering agent of this invention is added to the sludge to be treated, it coagulates the sludge into flocs by the action of the polymer flocculant, and releases glyoxal from the water-soluble medium, which eliminates the bad odor of the sludge. . After that, although glyoxal leaks to the water side, the surfactant is further deposited on the sludge and floc, so the action of the surfactant itself allows it to stay in place for a long time.7-.

As described above, this sludge dewatering agent has many advantages compared to the conventional technology, and is of great practical benefit.

The present invention will now be further explained by presenting examples of the present invention.

〔Example〕 1 temple → total + Deodorizing paper St was conducted on raw sewage sludge.

The chemical used was a powdered deodorizer (a:b=
l:x) (A) and benzalkonium chloride) and a homopolymer of N-dimethylaminomethyl sodium methacrylate as a polymer flocculant in a total ratio of 25:5 to 0 (weight ratio). It is a dehydrating agent.

First, 881% of the sludge dehydrating agent was added to raw sludge, stirred to form flocs, and then dehydrated using a belt press dehydrator.

Next, add 5 grams of the resulting dehydration case dFff to a 5 g container.
00? The container was placed in a sealed state and allowed to stand at room temperature. And 2
After an hour, 12 hours, and 24 hours, the odor inside the container was sampled, and the odor concentration was measured using a three-point comparative odor bag method.

In addition, in the odor concentration measuring method based on nature, the practical range is narrowed down to 10,000 or less.

Also, for comparison, only ingredient A was used instead of the deodorant.
Only component B and as conventional technology, wood acetic acid oil C)
Similarly, test stabs were conducted using glyoxal 0 supported on silica.

The results are shown in the table.

From this result, the present invention has excellent fast-acting properties and
Even after 24 hours, we were still below our target of 10,000 tons.
It can be seen that the durability is also satisfactory.

〔Effect of the invention〕

The sludge dewatering agent of this invention is entirely composed of water-soluble powder, and has extremely good handling and transportability, as well as the deodorizing effect it exhibits when added to sludge compared to conventional technology. It is a highly practical sludge dewatering agent with excellent fast-acting and continuous injection.

Claims (1)

[Claims] 1) A sludge dehydrating agent characterized by containing a water-soluble powder deodorant obtained by powdering glyoxal, a powdered polymer flocculant, and a powdered cationic surfactant 2) Powder The sludge dehydrating agent according to claim 1, wherein the sludge dehydrating agent according to claim 1, is a cationic surfactant. 4) The sludge dewatering agent according to claim 1 or 2, in which is benzalkonium chloride; 4) any one of claims 1 to 3, in which the powdered polymer flocculant is cationic; Sludge dewatering agent described in