KR100340999B1 - Method of producing a composite inorganic coagulant by using slag - Google Patents

Abstract

Environmentally friendly complex inorganic coagulant for the purpose of economical reduction of plating wastewater, domestic wastewater, livestock wastewater, etc. in a short time by using steelmaking slag generated as current waste in the treatment of industrial wastewater containing heavy metal and organic matter The manufacturing method of is disclosed. The composite inorganic coagulant according to the present invention is a powder product obtained by coating 100% by weight of steelmaking slag 0.1 to 20% by weight of the spiculipoic acid derivative represented by the following general formula (I) and 0.01 to 1% by weight of the absorbent polymer alone or in combination. .

(Wherein R represents Na, Ca, Mg, Al, alkoxy group, benzoyl group, polyoxyethylene group, polyoxypropylene group)

Industrial wastewater containing heavy metals and organic matter, that is, plating wastewater, livestock wastewater, domestic wastewater, etc., is aggregated and sedimented within a short time to make the sludge hydrophobic by the spiricolic acid derivative so as not to be eluted again. It allows for biodegradation.

Description

Manufacturing method of composite inorganic coagulant using steel by-product slag, industrial by-products {Method of producing a composite inorganic coagulant by using slag}

The present invention relates to the production of a composite inorganic coagulant, and more particularly, a short time for plating wastewater, domestic wastewater, animal husbandry wastewater, etc. using steelmaking slag generated as current waste during the treatment of industrial wastewater containing heavy metals and organic substances. The present invention relates to a method for producing an environmentally friendly composite inorganic coagulant which can be harmless and economical.

In general, for the treatment of heavy metal-containing wastewater, it has been adopted to separate the heavy metal-containing sludge from water with various chemicals, polymer flocculant and the like, and to dehydrate and dry the landfill or incinerate with various dehydration apparatus.

However, air pollutants are generated due to sublimation of heavy metal oxides and harmful gases caused by organic substances during combustion, and in the case of landfills, residues are leaked by leachate to generate secondary pollution.

In order to solve this problem, a method of dispersing or solidifying metal oxides or hydroxides in wastewater containing harmful substances such as heavy metals is used, but this is also not perfect and has a disadvantage in that the adsorbed heavy metals are leaked again. .

Recently, with the natural and acrylic market leading the treatment of wastewater, considerable research and commercialization have been conducted on kitchen / chitosan-based flocculants. In addition, the development of inexpensive and improved quality products is being spurred, and in Japan, the United States, and Germany, there is an increasing tendency to use inexpensive minerals as raw materials.

For example, US Pat. No. 5,569,385 discloses a method for treating wastewater in a food processing plant using an inorganic coagulant, and US Pat. No. 5,531,907 discloses a method for treating agricultural wastewater using an inorganic coagulant. have.

However, at present, domestic coagulants are weak in terms of economics and efficiency, as well as technically, so most of them are produced by introducing foreign technology.

Therefore, through the development of a high value added flocculant, it is necessary not only to remove the suspended solids (SS) but also to remove the harmful heavy metals or the harmful organic substances present in the aqueous solution (waste water) to improve the value and shorten the overall treatment process. It is emerging.

The present invention has been made to solve the conventional problems and problems as described above, the object of the present invention is to use a steel coating slag generated by a large amount of waste mixed mixed coating of the spiculosporic acid derivatives, The present invention provides a method for preparing a complex inorganic coagulant which can remove heavy metals and organics at the same time and is economical and environmentally nontoxic.

In order to achieve the above object, the present invention,

To 100 wt% of steelmaking slag, 1 to 10 wt% of the spiculispolic acid derivative represented by the following general formula (I) and 0.01 to 1 wt% of the absorbent polymer are added alone or in combination, and 20 w% of the porous additive is mixed and added as necessary. It provides a method for producing a composite inorganic coagulant, characterized in that it is prepared by.

(Wherein R represents Na, Ca, Mg, Al, alkoxy group, benzoyl group, polyoxyethylene group, polyoxypropylene group)

The absorbent polymer consists of a polyacrylic acid or sodium salt substituent, a polymethacryl, and a copolymer or sodium salt substituent of maleic anhydride and acrylic acid thereof.

The porous additive consists of lime, silica, hydrotalcite or cray.

As mentioned above, according to the present invention, an economical and efficient composite inorganic coagulant is prepared by using steelmaking slag as waste. The composite inorganic flocculant thus prepared aggregates and precipitates wastewater, plating wastewater, and livestock wastewater containing toxic organic matter and heavy metals in a short time so as not to be eluted again.

Hereinafter, the manufacturing method of the composite inorganic coagulant which concerns on this invention is demonstrated in detail.

In general, agglomeration is one of water treatment technologies that purify water by injecting a flocculant into a colloidal substance suspended in water to change the attraction and repulsive force between particles to form flocs and to precipitate and remove the formed flocs.

At present, with the increase of population and the development of cities and industries, the generation of sewage and wastewater is deteriorating not only quantitatively but also qualitatively. Therefore, there is a need for the development of a solid stabilizer that is simple to treat and has little leakage of various harmful substances.

In the present invention, it is intended to broaden the scope of application to various wastewater and to remove various harmful substances, especially heavy metals and organic substances at the same time, while being simple and economical and non-toxic. In particular, the main challenge was to develop a wastewater treatment stabilizer mixed with a coating of spiculosporic acid derivative using steelmaking slag generated as a large amount of waste.

In other words, by using steelmaking slag, which is mainly composed of calcium oxide and silica kelp generated as waste, it induces coagulation and sedimentation of industrial wastewater, plating wastewater, and livestock wastewater containing heavy metals and organic matters in a short time and is environmentally nontoxic. It is intended to produce an affinity flocculant.

Natural steel slag contains a large amount of pH-enhancing materials such as calcium oxide and magnesium oxide, co-precipitating and reducing materials such as MnO, SiO2, S, FeO, and adsorbent materials such as Al2O3, Fe2O3, and FeOOH. It has a high value as a neutralizing material, has a high specific gravity of 3.66, and has a low absorption rate, which facilitates sedimentation and improves dehydration rate.

On the surface of the steelmaking slag, the spiculosporic acid derivative and the absorbent polymer were selectively coated or mixed.

That is, a composite inorganic coagulant was prepared by coating 1 to 10 wt% of the spiculispolic acid derivative on 100 wt% of the steelmaking slag.

In contrast, a composite inorganic flocculant was prepared by coating 0.01-1 wt% of the absorbent polymer with 100 wt% of the steelmaking slag.

On the other hand, 100wt% of steelmaking slag is mixed with 1 ~ 10wt% of spiculosporic acid derivative and 0.01 ~ 1wt% of absorbent polymer to facilitate the capture of heavy metals and organics at the same time, preventing re-dissolution and dewatering of sludge. Improved efficiency In addition, a porous additive 20w% is added to increase the effect, and the porous additives used are lime, silica, hydrotalcite, cray, and the like.

The type of spiculic acid derivatives used herein is the same as the following general formula (I), and the absorbent polymer is a polyacrylic acid or a sodium salt substituent, a polymethacryl and a copolymer of maleic anhydride and acrylic acid, or a sodium salt. Substituent and the like.

(Wherein R represents Na, Ca, Mg, Al, alkoxy group, benzoyl group, polyoxyethylene group, polyoxypropylene group)

Al ₂ O ₃ , Fe ₂ O ₃ , FeOOH, etc. in steelmaking slag have porous adsorptive properties to adsorb harmful substances such as heavy metals and organic substances, and CaO, MgO, etc. It precipitates and induces fine colloidal particles and heavy metal components in the waste liquid by the action and the like. In addition, the highly biodegradable spiculispolic acid derivatives and absorbent polymers are located on the surface of the toxic substances adsorbed, so as not to be eluted again, they are captured while being hydrophobic.

CaO + H2O → Ca (OH) 2

Mn ++ n (OH-) → M (OH) n (II)

Results and Discussion

100wt% of steelmaking slag of 200mesh or less, 1wt% of spiculipoic acid derivative and 1wt% of sodium salt of polyacrylic acid (molecular weight 30,000 or more) are mixed and added to 20wt% of quicklime (95% or more of CaO content) to make a treatment agent. The characteristics were considered.

First, the physical and chemical properties of the steelmaking slag, the main material of the manufactured product, and the risk characteristics of the environment were evaluated. As shown in Table 1, the major mineral content of steelmaking slag is composed of SiO ₂ , Fe ₂ O ₃ , CaO main components and a specific gravity of 3.66.

In addition, the dissolution test results of the risk characteristics evaluation for the environment of steelmaking slag are shown in Table 2 below. In general, tests for effluents assess the composition of the effluent, the amount of leachate, and the environment in which the effluent is eluted. Likewise, the hazard criteria are considered to be environmentally harmless when waste is used at an undetectable level.

Table 1. Chemical composition

(Unit: mg / L)

SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO K ₂ O Na ₂ O TiO ₂ Ig.loss Sum Steelmaking slag 22.3 8.7 23.3 20.7 4.5 0.1 0.8 0.6 19.0 100.0

Table 2. Dissolution test of steelmaking slag

(Unit: mg / L)

Item As Cr Mn Fe Cu Zn CD Pb Hg Elution Steel slag ND ND 3.6 ND ND 1.38 ND ND ND

Next, 0.5 wt% of the composite inorganic coagulant was added to the actual waste liquid containing heavy metal copper, cadmium, zinc and oil components, and the mixture was sufficiently stirred for 2 hours using Jar Tester to measure the heavy metal and TOC content of the filtrate. Tables 3 and 4 show.

Table 3. Heavy metal measurement result by treatment agent

(Unit: mg / L)

Treatment solution Post-treatment solution Treatment efficiency (%) Copper cadmium zinc Copper cadmium zinc Copper cadmium zinc Treatment 26.1 40.2 480.5 0.3 0.26 1.23 98.85 99.35 99.74

Table 4. TOC and SS measurement results by treatment agent

(Unit: mg / L)

Treatment solution Post-treatment solution Treatment efficiency (%) TOC SS TOC SS TOC SS Treatment 100.2 147.2 37.2 1.3 62.87 99.12

As mentioned above, the composite inorganic coagulant prepared according to the present invention can be applied to various wastewater, such as plating wastewater, industrial wastewater, wastewater by metal processing and cutting, livestock wastewater, and economical and excellent treatment effect. In particular, it can be usefully used for industrial wastewater containing a large amount of heavy metals and organics.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

Claims (6)

A method for producing a composite inorganic coagulant, characterized in that it is prepared by coating 1 to 10 wt% of the spiculispolic acid derivative represented by the following general formula (I) to 100 wt% of steelmaking slag. (Wherein R represents Na, Ca, Mg, Al, alkoxy group, benzoyl group, polyoxyethylene group, polyoxypropylene group) A method for producing a composite inorganic coagulant, characterized in that the coating is prepared by adding 0.01-1 wt% of an absorbent polymer to 100 wt% of steelmaking slag. A method for producing a composite inorganic coagulant, characterized in that it is prepared by mixing and adding 1-10 wt% of spiculispolic acid derivative represented by the following general formula (I) and 0.01-1 wt% of absorbent polymer to 100 wt% of steelmaking slag. (Wherein R represents Na, Ca, Mg, Al, alkoxy group, benzoyl group, polyoxyethylene group, polyoxypropylene group) A composite inorganic material, which is prepared by mixing and adding 1-10 wt% of spiculisporic acid derivatives represented by the following general formula (I), 0.01-1 wt% of absorbent polymer, and 20w% of porous additives to 100wt% of steelmaking slag. Method of producing flocculant. (Wherein R represents Na, Ca, Mg, Al, alkoxy group, benzoyl group, polyoxyethylene group, polyoxypropylene group) The method of claim 4, wherein the absorbent polymer comprises a polyacrylic acid or a sodium salt substituent, a polymethacryl and a copolymer of the maleic anhydride and acrylic acid, or a sodium salt substituent. 5. The method of claim 4, wherein the porous additive is made of lime, silica, hydrotalcite or cray.