KR100960151B1 - Coagulant composition and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A coagulant composition and a manufacturing method thereof are provided to efficiently be used in water treatment for four seasons, and to improve cohesion efficiency under different pH, and turbidity conditions etc. CONSTITUTION: A manufacturing method of a coagulant composition comprises the following steps: reacting and mixing aluminum hydroxide 80 ~ 120 parts by weight and hydrochloric acid 150 ~ 250 parts by weight; additionally reacting a mixture with sulfuric acid 2 ~ 3 parts by weight; additionally reacting the mixture with a calcium carbonate aqueous solution 75 ~ 85 parts by weight; and reacting the mixture with epichlorohydrindimethylamine polyamine solution 16 ~ 27 parts by weigh and an aqueous solution of sodium carbonate 140 ~ 180 parts by weight.

Description

Coagulant composition and manufacturing method thereof

The present invention relates to a flocculant composition containing polyaluminum calcium chloride in which an amine is mixed and a method for producing the same.

Coagulants are classified into inorganic coagulants and organic coagulants, and polymer coagulants among inorganic coagulants have been widely used because of their high cohesive efficiency and superior rate of precipitation of impurities compared to single molecule coagulants. In particular, aluminum flocculants, which can generate chemical variants for water treatment, are mainly used. Polymerized monomers are used to polymerize aluminum ions. Typical examples include aluminum sulfate (LAS), poly aluminum chloride (PAC), poly aluminum chloride silicate (PACS), and poly aluminum chloride calcium (PACC). .

However, when these aluminum inorganic coagulants are used alone, the effect of removing organic matters and improving turbidity is not sufficient, and it is reported that aluminum ions remaining after water treatment can cause brain diseases such as Alzheimer's disease. Problems have been raised.

In addition, the conventional inorganic coagulants have a problem that the efficiency of removing organic matters and stability of the flocculant are greatly reduced by high turbidity and pH and the stability of organic matter treatment efficiency and coagulant greatly depends. This problem is especially high in Korea when the water properties change with seasons, such as in Korea, between the November and March seasons, due to the formation of algae, and when the turbidity is reached between the June and September seasons. The fluctuations in efficiency are so great that it is necessary to develop a flocculant that is applied to water treatment for four seasons.

Therefore, the present inventors have improved the instability of the product, which is a disadvantage of the low-basic aluminum-based inorganic coagulant, which is a disadvantage of the low basic aluminum-based inorganic coagulant, and it is not suitable for the four seasons. It has been found that it can be applied to complete the present invention.

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According to another aspect of the present invention, the present invention comprises the steps of (a) reacting by mixing aluminum hydroxide (Al ₂ O ₃ ) and hydrochloric acid (HCl) and then further by adding sulfuric acid (H ₂ SO ₄ ), (b A) reacting the reactant of step (a) by mixing and stirring an aqueous solution of calcium carbonate (CaCO ₃ ); It is an object to provide a method for producing a flocculant comprising the step of adding and stirring.

According to another aspect of the present invention, an object of the present invention is to provide a polyaluminum calcium chloride mixed with an amine which is a flocculant for water treatment produced by the above method.

According to another aspect of the present invention, the present invention comprises the steps of (a) reacting by mixing aluminum hydroxide (Al ₂ O ₃ ) and hydrochloric acid (HCl) and then further by adding sulfuric acid (H ₂ SO ₄ ), (b A) reacting the reactant of step (a) by mixing and stirring an aqueous solution of calcium carbonate (CaCO ₃ ); It provides a method for producing a flocculant comprising the step of adding and stirring.

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Hereinafter, the present invention will be described in more detail.

The flocculant composition of this invention is characterized by being polyaluminum calcium chloride mixed with amine.

The polyaluminum calcium chloride mixed with the amine of the present invention is polymerized by adding the organic coagulant after high basicizing the polyaluminum chloride (PAC), and the coagulant for water treatment containing polyaluminum calcium chloride mixed with the amine is broad. It exhibits good cohesive performance in the range of pH, turbidity and water temperature. Unlike conventional aluminum sulphate (LAS) or polyaluminum chloride (PAC), it does not require a neutralizing agent, and the aluminum removal rate is also very good with an efficiency of 99% and shows stability over 6 months. The polyaluminum calcium chloride mixed with amine increases the adsorption activity by cross-adsorption of fine floc particles during water treatment, and has high coagulation efficiency due to the action of polymer chain and organic coagulant. The concentration of the polyaluminum calcium chloride mixed with the amine in the water treatment is preferably 30-70 ppm, more preferably 30-55 ppm, more preferably 40-55 ppm.

In one embodiment of the present invention, the cohesion of the polyaluminum chloride mixed with the amine at the pH of turbidity 8.2NTU and 9.00 was confirmed, and aluminum sulfate (LAS) and polyaluminum chloride (PAC) were 1.8 NTU and 1.3 NTU, respectively. On the other hand, polyaluminum calcium chloride mixed with the amine of the present invention exhibited 0.40 NTU, confirming excellent cohesion.

The present invention

(a) reacting by mixing aluminum hydroxide (Al ₂ O ₃ ) and hydrochloric acid (HCl) and then adding sulfuric acid (H ₂ SO ₄ ) to further react,

(b) reacting the reactant of step (a) with a mixture of calcium carbonate (CaCO ₃ ) solution and stirring the mixture;

(c) providing a method of preparing a flocculant comprising adding and stirring an aqueous solution of sodium carbonate and an aqueous solution of epichlorohydrin dimethylamine polyamine, which is a polyamine organic coagulant, to the reaction product of step (b).

Step (a) is a process of increasing polymerization degree and polymerizing through polycondensation reaction to improve cohesion and storage stability. Preferably, aluminum hydroxide (Al ₂ O ₃ ) is 80-120 parts by weight and hydrochloric acid (HCl) is 150 -250 parts by weight and sulfuric acid (H ₂ SO ₄ ) is 2-3 parts by weight.

[Al2 (OH) nCl6-n] m produced by the reaction of aluminum hydroxide (Al ₂ O ₃ ) and hydrochloric acid (HCl) has improved stability and cohesion through polycondensation with sulfuric acid (H ₂ SO ₄ ). Preferably, the sulfate ion is 0.2 to 3%, and any compound to which sulfuric acid ions such as sodium sulfate, aluminum sulfate (LAS) and magnesium sulfate are added, as well as sulfuric acid, may be used. More preferably, step (a) is reacted under conditions of a temperature of 130-190 ° C. and a pressure of 5 kg / cm 3, hydrochloric acid (HCl) and aluminum hydroxide (Al ₂ O ₃ ) for 3-7 hours, sulfuric acid is added to further 3 The reaction is stirred for -7 hours.

Step (b) is a process in which CO 2 is generated and the base is highly basicized (70% base) with the reaction of the aqueous solution of calcium carbonate and the reaction solution produced in step (a). Preferably, the aqueous solution of calcium carbonate is 75-85 parts by weight. Preferably it is stirred for 1-4 hours at a temperature of 50-70 ℃, more preferably at 60-150 ℃ 150-300rpm, and reacted using a high speed mixer for dissolution efficiency and homogenization of calcium carbonate, the reaction scheme is as follows.

[Al ₂ (OH) nCl _6-n-2K (SO ₄ ) _K ] + CaCO ₃ + H ₂ O

→ Al _x (OH) _y Cl _z (SO ₄ ) _K + CaCl ₂ ↓

Where n is 2.5-4.5 and 0 ≦ K ≦ 4.

In step (c) preferably the aqueous sodium carbonate solution is 140-180 parts by weight, and the polyamine-based organic coagulant epichlorohydrin dimethylamine polyamine aqueous solution is 16-27 parts by weight. More preferably, the temperature is stirred at 1500-200 rpm for 1-3 hours while maintaining the temperature of 30-80 ° C. The aqueous solution of sodium carbonate is for complete high basicization, and the aqueous solution of epichlorohydrin-dimethylamine polyamine, which is a polyamine organic coagulant, improves turbidity of treated water by mixing water and organic / inorganic flocculant and improves floc strength and adsorption activity. Increase and improve the compressibility of the sludge. In addition, by showing excellent flocculation efficiency even in a small amount, the amount of flocculant used during water purification is reduced, and the effect of broadening the flocculation range is brought.

Polyaluminum aluminum chloride mixed with amine, which is a flocculant for water treatment of the present invention, exhibits excellent flocculation function at various pH, turbidity, etc. with a small capacity, and in particular, existing aluminum sulfate (LAS) or polychloride at high pH and It is confirmed that it exhibits a higher efficiency of coagulation efficiency than a coagulant such as aluminum (PAC), and it can be used for water treatment for four seasons with stability even at a basicity of 70% or more.

In the following Preparation Examples and Examples, a method of preparing polyaluminum chloride mixed with an amine and a flocculant for water treatment have been disclosed, but are not limited thereto, and include a range of methods and ranges of use that can be easily considered by those skilled in the art. .

Preparation Example 1 Preparation of Polyaluminum Calcium Chloride Coagulant Mixed with Amines

After 200 kg of hydrochloric acid and 100 kg of aluminum hydroxide were stirred for 5 hours at a temperature of 160 ° C. and a pressure of 5 kg / cm 3, 2.5 kg of sulfuric acid was added so that 1% of sulfate ions were added, followed by an additional 2 hours at the same temperature and pressure. Stirred. Then, add an aqueous calcium carbonate solution (7 kg of calcium carbonate and 72 kg of water), stir at 200 rpm at 60 ° C. for 2 hours, an aqueous sodium carbonate solution (40 kg of sodium carbonate and 120 kg of water) and an aqueous solution of epichlorohydrin dimethylamine polyamine as a polyamine organic coagulant ( 1.5 kg of coagulant and 20 kg of water) were added thereto, and further stirred at 150-200 rpm at 50 ° C. for 2 hours to prepare a polyaluminum calcium chloride coagulant mixed with amine.

In order to confirm the coagulation efficacy of the polyaluminum calcium chloride coagulant mixed with the amine prepared according to Preparation Example 1, a coagulation agitation test (Jar Test) was performed under various conditions to be combined with aluminum sulfate (LAS) and polyaluminum chloride (PAC). Efficacy was compared.

Example  One.

The coagulation stirring test takes a sample at 5 cm from the bottom under conditions of 1 minute at 150 rpm for rapid stirring, 10 minutes at 50 rpm for slow stirring, and 1 minute at 20 rpm for 10 minutes, and the raw water is pH 9.00, turbidity 8.2 NTU, COD 13.80 It was carried out under the conditions of mg / L, water temperature of 14 ℃ and raw water alkalinity of 75 mg / L, 65 ppm of aluminum sulfate (LAS), 45 ppm of poly aluminum chloride (PAC) and 45 ppm of polyaluminum calcium chloride mixed with an amine.

As a result, when the polyaluminum chloride mixed with the amine of the present invention was used, the turbidity was measured at 0.4 NTU, which was much lower than that of aluminum sulfate (LAS) using about 1.5 times higher concentration, and the polyaluminum chloride measured at 1.3 NTU. The value of 0.9 was lower than that of (PAC), indicating that suspended solids removal efficiency was superior to that of conventional aluminum flocculant (Table 1).

Aluminum sulfate
(LAS) Poly Aluminum Chloride
(PAC) Polyaluminum calcium chloride mixed with amine Coagulant Input (ppm) 65 45 45 Treated Water Turbidity (NTU) 1.8 1.3 0.40 Treated Water pH 7.5 8.0 7.9 Treated water alkalinity (CaCO ₃ ) (ppm) 58 66 65

Example  2

The coagulation agitation test takes 1 minute at 150 rpm for rapid stirring, 10 minutes at 50 rpm for slow stirring, and 1 minute at 20 rpm for 5 minutes at the bottom under standing 10 minutes, and the raw water is pH 9.54, turbidity 7.41 NTU, water temperature 10 It was carried out under the conditions of ℃ and raw water alkalinity 70mg / L, amine-mixed polyaluminum calcium chloride 30, 35, 40, 45 and 50ppm, aluminum sulfate (LAS) and polyaluminum chloride (PAC) is 45, 50, 55 , 60, 65 and 70ppm was added to measure the water treatment function according to the flocculant concentration.

As a result, polyaluminum calcium chloride mixed with amines significantly reduced turbidity even when treated at relatively low concentrations. Aluminum sulfate (LAS) and polyaluminum chloride were measured at about 0.5 NTU at 50 ppm and at about 1.1 NTU at the same concentration. (PAC) showed more than twice the value, confirming the superior water treatment capacity (Fig. 1). In addition, when polyaluminum calcium chloride mixed with 50 ppm of amine, 70 ppm of aluminum sulfate (LAS) and polyaluminum chloride (PAC) was used, it showed a similar effect as about 0.5 NTU. When calcium aluminum chloride was used, it was shown that the same effect can be obtained at a very low concentration compared to the existing flocculant, and thus the excellent efficacy of the polyaluminum calcium chloride flocculant mixed with the amine of the present invention was confirmed.

Example  3

Samples were taken at 5 cm from the bottom under conditions of rapid stirring at 150 rpm for 1 minute, slow stirring at 50 rpm for 10 minutes and 20 rpm for 1 minute, and stationary for 10 minutes. Raw water was pH 7.8, turbidity 35 NTU, COD 13.80 mg / L, water temperature The turbidity was performed at 17 ° C. and raw water alkalinity of 27 mg / L, and 75 ppm of aluminum sulfate (LAS), 40 ppm of polyaluminum chloride (PAC), and 40 ppm of polyaluminum calcium chloride mixed with amine were added thereto.

As a result, the use of polyaluminum calcium chloride mixed with amine showed a very good coagulation effect than aluminum sulfate (LAS) measured at 2.62 NTU, and more than twice as low as the relatively effective poly aluminum chloride (PAC) at 0.73 NTU. The figures are shown (Table 2).

Aluminum sulfate
(LAS) Poly Aluminum Chloride
(PAC) Polyaluminum calcium chloride mixed with amine Coagulant Input (ppm) 75 40 40 Treated Water Turbidity (NTU) 2.62 1.9 0.73 Treated Water pH 5.6 7.1 6.8 Treated water alkalinity (CaCO ₃ ) (ppm) 7.3 20.8 18.6

1 is a graph showing the cohesion of polyaluminum chloride amine (polyaluminum chloride mixed with amine), polyaluminum chloride (PAC), and aluminum sulfate (LAS).

Claims (4)

delete (a) reacting by mixing aluminum hydroxide (Al ₂ O ₃ ) and hydrochloric acid (HCl); (b) further reacting by adding sulfuric acid (H ₂ SO ₄ ) after the reaction of step (a); (c) after the reaction of step (b), further reaction by adding calcium carbonate (CaCO ₃ ) solution; And (d) after the reaction of step (c), by further reacting by adding an aqueous solution of sodium carbonate and an aqueous solution of epichlorohydrin dimethylamine polyamine which is a polyamine-based organic coagulant; The method of claim 2, In step (a), aluminum hydroxide (Al ₂ O ₃ ) to 80 to 120 parts by weight, hydrochloric acid (HCl) is mixed to 150 to 250 parts by weight; Sulfuric acid (H ₂ SO ₄ ) is added in an amount of 2 to 3 parts by weight in step (b); Adding (c) 75 to 85 parts by weight of an aqueous solution of calcium carbonate (CaCO ₃ ); 140 to 180 parts by weight of the aqueous solution of sodium carbonate in step (d), 16 to 27 parts by weight of an aqueous solution of epichlorohydrin dimethylamine polyamine which is a polyamine-based organic coagulant. The method of claim 3, wherein In step (a), aluminum hydroxide (Al ₂ O ₃ ) and hydrochloric acid are reacted at 130 to 190 ° C. under a pressure of 4 to 6 kg / cm ³ for 3 to 7 hours; In step (b), sulfuric acid (H ₂ SO ₄ ) is added and further reacted for 3 to 7 hours; Adding the aqueous calcium carbonate solution in step (c) and reacting at 50 to 70 ° C. for 1 to 4 hours; The method of producing a flocculant composition, characterized in that in step (d) is added an aqueous solution of sodium carbonate and epichlorohydrin dimethylamine polyamine aqueous solution of polyamine organic coagulant for 1 to 3 hours at 30 to 80 ℃.

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