JPS61278348A - Treatment of adsorbent - Google Patents

Abstract

PURPOSE:To spread the titled adsorbent in which the eutrophicating ingredients such as nitrogen and phosphorus present in the excrement waste water is adsorbed onto the farmland, etc. and to utilize said adsorbent as the fertilizer ingredients of the plant by contacting said adsorbent composed of a specified part by weight of zeorite and the rest of clay which has been subjected to an aluminum treatment with the excrement waste water, etc. CONSTITUTION:The adsorbent composed of 10-90pts.wt. high nitrogen- adsorptive zeolite and the rest of clay whose phosphorus adsorbability is increased by being subjected to the aluminum treatment is contacted with the excrement waste water, domestic waste water, etc. to adsorb nitrogen and phosphorus. The aluminum treatment is the operation of allowing the fine precipitate of aluminum hydroxide to adhere onto the surface of the clay by adjusting pH of the clay-suspended solution in which aluminum-containing salts are dissolved. The treatment of the used adsorbent results in unnecessaries by spreading the desired adsorbent in which nitrogen and phosphorus are adsorbed onto the farmland, etc. as the fertilizer.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for treating an adsorbent, and particularly to a method for treating an adsorbent used as a fertilizer component.

(Prior Art) Currently, the water quality of rivers, lakes, and inland seas in Japan is deteriorating. The problems associated with the eutrophication of land and seawater are not only damaging fish and shellfish due to red tide and abnormal growth of algae, but are also threatening water supply sources. The cause of this eutrophication is said to be ammonia nitrogen and phosphate dissolved in water.

In addition, algae that have grown abnormally due to eutrophication die and are deposited on the lake or riverbed, and when they rot, they consume dissolved oxygen in the surface water, add BOD, and become a source of eutrophic nutrients. Unless they are removed, it seems impossible to break this vicious cycle.

The critical concentration for eutrophication of phosphorus and nitrogen is [lL]
o 2 ppm nitrogen is supposed to be 12 ppm.

Furthermore, the simultaneous presence of phosphorus and nitrogen is said to have a strong effect on the growth of algae.

The major sources of phosphorus and nitrogen are human waste, domestic wastewater, and salt runoff from farmland and forests. In addition, in areas where livestock farming is popular, this can become a major source of pollution.

Of the sources of phosphorus and nitrogen, human waste and domestic wastewater can be gradually eliminated through the use of substitutes such as phosphorus-free detergents and through equipment improvements such as the installation of sewers and sewage treatment plants. The current situation is that emissions are decreasing.

However, the current situation is that nothing is being done to prevent salt runoff from agricultural land, mountains, and forests, and in many cases, fertilizers applied to farmland that run off with rainwater and flow into rivers, lakes, etc.

Furthermore, the current situation is that human waste wastewater from small-scale livestock farms and small-scale domestic wastewater are discharged without any treatment.

(Problems to be Solved by the Invention) The present invention has been developed as a result of extensive research in consideration of the social situation described above, and has been developed to create a wastewater treatment adsorbent that causes less phosphorus and nitrogen component runoff and can be used as a fertilizer component. This paper proposes a processing method for

(Means for Solving the Problems) The present invention involves bringing 10 to 90 parts by weight of zeolite into contact with various types of wastewater, such as night soil wastewater or domestic wastewater, using an adsorbent consisting of clay treated with aluminum, and The present invention relates to a method for treating an adsorbent, which is characterized in that the adsorbent adsorbing eutrophic components such as nitrogen and phosphorus contained in the soil is sprayed onto fields, etc., and used as a fertilizer component for plants.

In the present invention, aluminum-treated clay with high phosphorus adsorption performance and zeolite with high nitrogen adsorption performance are brought into contact with wastewater containing nitrogen or phosphorus, such as livestock human waste wastewater or domestic wastewater, to adsorb it.

After adsorption, the above-mentioned clay or zeolite is sprayed on fields and used as a fertilizer component necessary for plants.

In order to adsorb this, a positive or negative ion adsorbent is required.

Zeolite is an aluminosilicate mainly composed of naturally occurring silica and alumina, and generally has a high cation exchange capacity. Although many types are known, mordenite or oblique butyrolite is common in Japan.

Clays are naturally occurring and usually have weak cation or anion adsorption properties, but their capacity is not large enough to be used as an adsorbent. Therefore, in the present invention, aluminum treatment is performed to positively charge the surface and increase anion adsorption.

Aluminum treatment involves dissolving an aluminum-containing salt such as aluminum chloride in a suspension of clay, adjusting the pH, and depositing fine precipitates of aluminum hydroxide on the surface of the particles. For example, AtC4tAl1(
S04) M compounds such as At(NO3)3 are dissolved in water at a ratio of 1 to 10 wt% to form an aqueous solution, and this aqueous solution is adjusted to p)(about 6 to 8. As a pH adjuster, hydrochloric acid.

(Sulfuric acid, nitric acid, etc. can also be used, as well as ammonia water, acidic soda, etc.) Disperse 10 to 100 parts by weight of clay to 500 parts by weight of water in this aqueous solution, stir for 5 to 60 minutes to form a uniform slurry, and then neutralize by adding acid or alkali to produce aluminum hydroxide. precipitates and adheres to the clay surface. Thereafter, after washing with water and drying, At treatment is performed.

The adsorbent prepared as described above is brought into contact with wastewater to adsorb phosphorus or nitrogen.

After using the adsorbent, it is sprayed on fields and used as a fertilizer containing phosphorus and nitrogen. This eliminates the need to worry about disposing of the adsorbent after use.

Furthermore, this adsorbent is expected to act as a soil conditioner in fields.

The soil conditions vary from place to place, and if the soil is rich in kaolin minerals, such as volcanic ash soil, sandy soil, or granite, the retention effect of the soil on phosphorus and nitrogen components will be small, so soil conditioners may be used. Zeolite is used as a material.

The present invention is a useful wastewater treatment method that uses an adsorbent to treat wastewater and at the same time uses the used adsorbent as fertilizer.

Hereinafter, the present invention will be explained according to examples.

(Example) Example 1 Zeolite produced in Itaya, Yamagata Prefecture and kaolinite clay of Aichi yarn amount treated with aluminum were used as an adsorbent.

The zeolite used was pulverized to less than &36 kg.

For aluminum treatment of kaolinitic clay, 100 parts by weight of the clay was dispersed in an aqueous solution of 10 parts by weight of aluminum chloride dissolved in 500 parts by weight of water, stirred for 24 hours, and then 3N hydroxide was added. After adjusting the pH to 5, the solution was washed, filtered, and dried.

Add phosphoric acid and ammonia water as a drainage simulating liquid, and
a degree 1000 ppI” F N'H4 concentration 100
A No. 0 ppm water solution was prepared.

The adsorption test was carried out using the adsorption test apparatus shown in FIG. In FIG. 1, 1 is an adsorption tower, 2 and 3 are respective adsorbent peds, 4 is a wastewater simulating liquid supply device, and 5 is an adsorption tower.
is a liquid receiver.

1 kg of zeolite, 1 kg of aluminum-treated clay
g was filled into adsorbent peds 2 and 3, respectively, and an adsorption test was conducted. The concentration of the effluent at the time when the simulated liquid was passed through S was 10 ppm for POney, and 10 ppm for NHjS.
However, adsorption by the adsorbent was observed, proving that the treatment method using this adsorbent is useful.

Next, by continuously supplying the simulated liquid and determining the adsorption capacity of the adsorbent at the time of breakthrough, it was found that zeolite was 2.5% of the total amount of zeolite, and aluminum-treated clay was 2.5% of the total amount of zeolite. In contrast, MC was hardly recognized.

Example 2 Zeolite from Tenei, Fukushima Prefecture and kaolinitic clay from Hiroshima, which was treated with aluminum, were used as adsorbents. The zeolite used was pulverized to 556 mm or less.

Aluminum treatment of kaolinitic clay involves dispersing 100 parts by weight of clay in an aqueous solution of 20 parts by weight of aluminum sulfate in 500 parts by weight of water, stirring for 24 hours, and then adjusting the pH to 5 by adding 3N sodium hydroxide. After that, wash 3
This was carried out by filtering and drying.

Phosphoric acid and aqueous ammonia were added as a drainage simulating liquid to give a Pony concentration of 500 ppm and an NH4 concentration of 500 ppm.
An aqueous solution was prepared.

The adsorption test was carried out using the adsorption test apparatus shown in FIG.

1 kg of zeolite, 9 clays with aluminum treatment 1
kg was filled into the positions of adsorbent peds 2 and 3, respectively, and an adsorption test was conducted.

Figure 2 shows the adsorption test results. The horizontal axis is the amount of liquid processed;
The vertical axis is po4 in the effluent. This is the NH4 concentration. In this test, it was found that it was possible to reduce the concentration by adsorption compared to the water amount of 40tXNI (4+) in the case of po4"- and SOt.

In addition, after the adsorption capacity of the adsorbent has broken through, the adsorption capacity after processing 100% from the beginning (i.e., when the concentration in the passing liquid reaches 500 ppm, which is the concentration of the stock solution), is the adsorption capacity of the zeolite. MC was 2.7%, and po4''-2.0% was found in the aluminum-treated clay.Also, almost no pony was observed in the zeolite, and almost no NH4 was observed in the aluminum-treated clay.

Since the adsorption capacity is constant for each adsorbent, the p
It can be seen that the amount of adsorbent may be changed in the range of 10 to 90 parts by weight of zeolite, which is the range of the present invention, and the remainder of aluminum-treated clay, depending on the ratio of the amounts of 1 and 1 present in the adsorption tower.

The adsorbent can be released by supplying water, etc., and if it is sprayed on fields, it will work as a fertilizer component. In addition, the zeolite contained in the present adsorbent has been used as an agricultural soil conditioner, and when sprayed on soil, it exhibits a soil improving effect for many years. 4. It is useful to spray pony adsorbed pony on fields, etc., and there is no need to worry about the treated area.

[Brief explanation of drawings]

FIG. 1 is a diagram schematically showing a test apparatus used in carrying out the present invention. FIG. 2 is a diagram showing the results of an adsorption test using an adsorbent. Sub-Agents 1) Meifuku Agent Ryo Hagiwara - Sub-Agent Atsuo Anzai Figure 1

Claims (1)

[Claims] An adsorbent consisting of 10 to 90 parts by weight of zeolite and the rest of the clay treated with aluminum is brought into contact with various types of wastewater such as night soil wastewater or domestic wastewater, and adsorbs eutrophic components such as nitrogen and phosphorus contained in the wastewater. A method for treating an adsorbent, which comprises spraying the adsorbent on a field or the like and using it as a fertilizer component for plants.