JPS6251654B2 - - Google Patents

Description

[Detailed description of the invention]

Industrial Application Fields The present invention is a novel composite adsorbent, more specifically, it exhibits excellent trapping effects on various metal ions, organic substances, nitrogen compounds, etc., and has mechanical strength and
This invention relates to a composite adsorbent that has excellent resistance to expansion and contraction, durability, etc., and can be manufactured at low cost. Industrial wastewater discharged from metal product manufacturing industries, chemical industries, etc. contains metal ions, organic substances, nitrogen compounds, etc., and since these have various effects on the human body, most of them are treated before being discharged. Complete removal is required. BACKGROUND ART Conventionally, as a means for removing these substances, adsorption treatment methods using, for example, ion exchange resins or activated carbon are known. However, although commercially available adsorbents such as ion-exchange resins and activated carbon are used as advanced treatment agents for wastewater, they are limited in the types of substances they can adsorb and are also expensive, so they can be used in high concentrations and in many types. It is unsuitable for treating wastewater containing pollutants. Therefore, in wastewater treatment, there has been a demand for the development of an inexpensive adsorbent that can simultaneously trap various pollutants such as metal ions, organic substances, and nitrogen compounds. Furthermore, conventional adsorbents are not necessarily satisfactory in terms of mechanical strength, resistance to expansion and contraction, durability, etc., and improvements in these have been desired. Problems to be Solved by the Invention The purpose of the present invention is to meet these demands, to exhibit excellent trapping effects on various metal ions, organic substances, nitrogen compounds, etc., and to have mechanical strength, expansion and contraction resistance, The object of the present invention is to provide a composite adsorbent that has excellent durability and can be manufactured at low cost. Means for Solving the Problems As a result of various studies, the present inventors found that by coating the surface of a finely powdered solid substance with a specific copolymer and then bonding amino alcohol molecules to this copolymer, We have discovered that the above object can be achieved, and based on this knowledge, we have completed the present invention. That is, in the present invention, on the surface of a finely powdered solid substance,
The present invention provides a composite adsorbent coated with a copolymer of an α,β-unsaturated carboxylic acid or its ester and a crosslinkable divinyl monomer, and bound to an amino alcohol. The fine powder solid substance used in the composite adsorbent of the present invention is an inorganic or organic solid substance with a large surface area, such as silica gel, synthetic zeolite, natural zeolite, molecular sieves, alumina, carbon black, etc. , activated carbon, cellulose, etc. These may be used alone or in combination of two or more. In addition, examples of the α,β-unsaturated carboxylic acid or its ester used to form the copolymer in the composite adsorbent include acrylic acid,
Methacrylic acid, crotonic acid, etc., or alkyl esters thereof such as methyl ester, ethyl ester, propyl ester, butyl ester, such as methyl acrylate, ethyl acrylate, propyl acrylate, methyl methacrylate, ethyl methacrylate, etc. Can be done. These may be used alone or in combination of two or more. On the other hand, examples of the crosslinkable divinyl monomer to be copolymerized with such α,β-unsaturated carboxylic acid or its ester include divinylbenzene,
Examples include aromatic divinyl compounds such as divinyltoluene and divinylnaphthalene, and aliphatic divinyl compounds such as ethylene glycol diacrylate and ethylene glycol dimethacrylate. The main purpose of these crosslinkable divinyl monomers is to crosslink the polymer formed by polymerizing the α,β-unsaturated carboxylic acid or its ester and improve its physical properties. is selected depending on the desired degree of crosslinking. In order to produce the composite adsorbent of the present invention, first, the surface of the fine powder solid substance is coated with a copolymer of an α,β-unsaturated carboxylic acid or its ester and a crosslinkable divinyl monomer. . This coating method includes, for example, a method in which the fine powder solid substance is suspended in a solution containing these monomers and a polymerization initiator and then copolymerized, or a method in which the fine powder solid substance is copolymerized with these monomers. Preferred is a method in which copolymerization is carried out in a non-medium by adsorbing an initiator. Next, amino alcohol is bonded to the copolymer thus coated on the surface of the finely powdered solid material. Examples of the amino alcohol include ethanolamine, diethanolamine, 2-aminopropan-1-ol, 1-aminopropan-
2,3-diol, 2-amino-1,3 dioxybutane, tris(oxymethyl)methylamine,
1,3-diaminopropan-2-ol, 1,3
Diaminopropan-3-ol, (2-oxyethyl)ethylenediamine, etc. are used. As a method for introducing such an amino alcohol into the copolymer, for example, amino alcohol is added to the total molar amount of α,β-unsaturated carboxylic acid units or ester units thereof contained in the copolymer.
A method is used in which the amount is used in a range of 0.1 to 100 times, preferably 1 to 10 times, and reacted with the copolymer.
At this time, in order to carry out the reaction effectively, an organic solvent which acts as a swelling agent for the copolymer and can dissolve the amino alcohol may be used. Examples of such organic solvents include dioxane, acetone, methyl ethyl ketone, benzene, toluene, N,N
-Dimethylformamide, etc. In this way, the carboxyl group or ester group of the copolymer coated on the surface of the fine powder solid material reacts with the amino group of the amino alcohol to form an acid amide or by performing a transesterification reaction. Amino alcohol is introduced into the copolymer to obtain the composite adsorbent of the present invention. Effects of the Invention The composite adsorbent of the present invention has a resin that strongly adheres to the surface of a finely powdered solid material, and has excellent mechanical strength, resistance to expansion and contraction, and durability. It is a new adsorbent with high practical value because it has both the adsorption ability of resin and has an excellent trapping effect on various metal ions, organic substances, nitrogen compounds, etc., and can be manufactured at low cost. be. Therefore, the adsorbent of the present invention can be suitably used for purifying industrial wastewater containing various metal ions, organic substances, nitrogen compounds, and the like. EXAMPLES Next, the present invention will be explained in more detail with reference to Examples. Example 1 A mixed monomer of α,β-unsaturated carboxylic acid or its ester and divinylbenzene as shown in the following table and azobisisobutyronitrile as a polymerization initiator were added to silica gel sized into 60 to 100 meshes. After adsorption, copolymerization was carried out at 80°C for 5 hours. Copolymer-coated silica gel 10 obtained by this reaction
A predetermined amount of amino alcohol as shown in the table was added to g, and the mixture was reacted at a predetermined temperature for a predetermined time using a solvent if necessary. The reaction product was washed with IN hydrochloric acid and water, and then purified by Soxhlet extraction with methanol. The results are summarized in the table. In the infrared reflection/reflection absorption spectra of these products, a new acid amide peak appears around 1650 cm ^-1 , and according to differential calorimetry analysis, the temperature is between 450 and 50°C.
A new exothermic peak and associated weight loss were observed in the vicinity. From these results, it was found that the increase in weight of the product was due to the reaction of the amino alcohol. All of these products rapidly adsorbed hexavalent chromium, copper, nickel, zinc, and lead. As an example, the results of the copper adsorption experiment of the product obtained in experiment number 1 in the table are shown in Figure 1 with curve A.
It was shown in In this adsorption experiment, 50ml of a solution with a copper concentration of 10mg/
Add 100 mg of the product to the solution, adjust the pH of the solution by stirring at room temperature, let it stand for 3 days, stir for 1 day, measure the equilibrium pH of the solution, and check the remaining copper in the solution. The concentration was determined. The pH of the solution was adjusted using dilute hydrochloric acid and dilute aqueous sodium hydroxide solution, and the concentration was corrected based on the volume added. This product forms a chelate with copper, and as can be seen from Figure 1, the product has a pH of 6 to 7.5. 85%~
99.8% of copper could be removed.

[Table] Example 2 A mixed monomer of methyl methacrylate and divinylbenzene (weight ratio 100:1) and azobisisobutyronitrile were adsorbed onto natural zeolite sized into 60 to 100 meshes, and then heated at 80°C. The reaction was carried out for 5 hours. This reaction reduces the copolymer content
A 25.2% by weight copolymer coated natural zeolite was obtained. Add 10 g of this product to 50 ml of N,N-dimethylformamide and swell the copolymer while stirring at room temperature, then add 19.2 g of 1,3 diaminopropan-2-ol and react at 175°C for 10 hours. I let it happen. After the reaction was completed, the product was purified in the same manner as in Example 1 to obtain 10.5 g of a reaction product. This product quickly adsorbs NH ⁺ ₄ , Zn ²⁺ , and Cr ⁶⁺ , and its adsorption capacity is 1.44 meq/g, respectively.
It showed 0.32 mmol/g and 0.28 mmol/g. In addition, a solution containing a pretreatment agent (COD
200 mg of the product was added to 50 ml of 150 mg/) and an adsorption experiment was carried out in the same manner as in Example 1.
Measure the COD value and show the results as curve B in Figure 2.
It was shown in For comparison, curve C shows the case where natural zeolite was used. As can be seen from Figure 2, the product showed a COD component removal rate of about 45% over a wide pH range, but the natural zeolite used as a raw material had low adsorption performance for COD components.
Almost no COD components were removed. Example 3 A mixed monomer of methyl methacrylate and divinylbenzene (weight ratio 100:5) and benzoyl peroxide were adsorbed onto activated carbon sized into 10 to 20 meshes, and then reacted at 100°C for 5 hours. This reaction yielded copolymer-coated activated carbon with a copolymer content of 15.0% by weight. 10g of this stuff is N,
After adding it to 50 ml of N-dimethylformamide and stirring at room temperature to swell the copolymer, 2-
(2-Aminoethylamino) Add ethanol
After reacting at 175°C for 7 hours, it was purified in the same manner as in Example 1 to obtain 10.7 g of a reaction product. Using 200 mg of this product, Cu ²⁺ , Pb ²⁺ and
Contains 10mg/each of Cr ⁶⁺ , COD value 150
Adsorption treatment of 50ml of Metsuki pretreatment solution of mg/PH
I went with 7.0. As a result, each removal rate is
Cu ²⁺ 95.4%, Pb ²⁺ 93.2%, Cr ⁶⁺ 90.6%,
The COD component was 48.6%, and it was possible to simultaneously remove the COD component and metal ions through adsorption treatment using this product.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between the equilibrium pH of the solution and the copper removal rate when the composite adsorbent of the present invention is added to a copper-containing solution, and FIG. It is a graph showing the relationship between the equilibrium pH of the solution and the removal rate of COD components when an adsorbent and natural zeolite are respectively added. In the graph, curve A and curve B are for the composite adsorbent of the present invention, and curve C is for natural zeolite.

Claims (1)

[Claims] 1. A composite adsorbent in which the surface of a finely powdered solid substance is coated with a copolymer of α,β-unsaturated carboxylic acid or its ester and a crosslinkable divinyl monomer, and an amino alcohol is bonded to the copolymer.