KR910002358B1 - Flocculating agents of kitonic acid copolymer - Google Patents

Abstract

The chitosan copolymer based-cohering agent is prepd. by graft copolymerization of chitosan, and acrylic acid or acryl amide in the presence of ceric ammonium nitrate as an initiator. The cohering agent has 3.17-4.42x105 of viscosity NVC. molecular weight. Pref. the reaction temp. is 30-55 C. The obtd. chitosan based cohering agent is useful for the treatment of waste water.

Description

Flocculant of chitosan copolymers and uses thereof

1 is a graph showing the IR spectra of polyacrylic acid (PAA), chitosan (A ₁ ) and chitosan (C) grafted with acrylic acid.

2 is a graph showing IR spectra of polyacrylamide (PAM), acrylamide-grafted chitosan (A ₂ ) and chitosan (C).

v) : PAA-1=4.25×10⁵, PAA-2=9.87×10⁵,A₁-4=4.35×10⁵)의 첨가량에 대한 침강속도를 나타내는 그래프.3 shows homopolymers of polyacrylic acid having different molecular weights and copolymers in which acrylic acid is grafted in a 0.4 wt% -kaolin suspension at pH 4.4 (viscosity average molecular weight (

v): Graph showing sedimentation rate with respect to addition amount of PAA-1 = 4.25 × 10 ⁵ , PAA-2 = 9.87 × 10 ⁵ , A ₁ -4 = 4.35 × 10 ⁵ ).

V) : PAA-1=4.25×10⁵, PAA-2=9.87×10⁵, A₁-4=4.35×10⁵)의 첨가량에 대한 투과도를 나타내는 그래프.4 shows homopolymers of polyacrylic acid having different molecular weights and copolymers in which acrylic acid is grafted in a 0.4 wt% -kaolin suspension at pH 4.4 (viscosity average molecular weight (

V): A graph showing the permeability with respect to the addition amount of PAA-1 = 4.25 × 10 ⁵ , PAA-2 = 9.87 × 10 ⁵ , A ₁ -4 = 4.35 × 10 ⁵ ).

5 is similar to FIG. 3, with a pH of 9.7.

6 is similar to FIG. 4, with a pH of 9.7.

v) : PAM-1=3.85×10⁵, PAM-2=10.21×10, A₂-4=4.12×10⁵)의 첨가량에 대한 침강속도를 나타내는 그래프.7 shows homopolymers of polyacrylamide and copolymers grafted with acrylamide in a 4% by weight kaolin suspension at pH 3.8 (viscosity average molecular weight

v): Graph showing sedimentation rate with respect to the addition amount of PAM-1 = 3.85 × 10 ⁵ , PAM-2 = 10.21 × 10, A ₂ -4 = 4.12 × 10 ⁵ ).

v) : PAM-1=3.85×10⁵, PAM-2=10.21×10⁵, A₂-4=4.12×10⁵)의 첨가량에 대한 투과도를 나타내는 그래프.FIG. 8 shows homopolymers of polyacrylamide and copolymers grafted with acrylamide in a 4 wt% -kaolin suspension at pH 3.8 (viscosity average molecular weight

v): PAM-1 = 3.85 × 10 ⁵ , PAM-2 = 10.21 × 10 ⁵ , A ₂ -4 = 4.12 × 10 ⁵ ) A graph showing the permeability with respect to the addition amount.

)의 산성 pH값에 대한 침강속도를 나타내는 그래프.Ninth turning 0.4 wt% - kaolin suspension (A applied _l -4 flocculant amount: 35.71mg /

Graph showing sedimentation rate versus acidic pH value of

)의 산성 pH값에 대한 투과도를 나타내는 그래프.Claim 10 degrees 0.4 wt% - kaolin suspension (A applied _l -4 flocculant amount: 35.71mg /

A graph showing the permeability to acidic pH value of).

), 가해진 Al₂(SO₄)₃의 량 : 0.8g/

)의 알칼리성 pH값에 대한 침강속도를 나타내는 그래프.Claim 11 degrees 0.4 wt% - kaolin suspension (A applied _l -4 flocculant amount: 35.71mg /

), Amount of Al ₂ (SO ₄ ) _{3 added} : 0.8 g /

Graph showing sedimentation rate with respect to alkaline pH value).

, 가해진 Al₂(SO₄)₃의 량 : 0.8g/

)의 알칼리성 pH값에 대한 투과도를 나타내는 그래프.Figure 12 shows 0.4% by weight kaolin suspension (amount of A _1-4 coagulant added: 35.71 mg /

, Amount of Al ₂ (SO ₄ ) _{3 added} : 0.8 g /

A graph showing the permeability to the alkaline pH value of).

)에 있어서의 pH값에 대한 침강속도를 나타내는 그래프.Figure 13 shows 4% by weight of kaolin suspension (amount of A _2-4 coagulant added: 50 mg /

Graph showing the sedimentation rate with respect to the pH value in).

FIG. 14 is a graph showing sedimentation rate and permeability with respect to the amount of A _2-4 coagulant added in a 4 wt% -kaolin suspension having various pH values, with dotted lines representing permeability and solid lines representing sedimentation rates.

v) : A_l-1=3.18×10⁵, A₁-2=3.52×10⁵, A₁-4=4.35×10⁵)의 첨가량에 대한 침강속도를 나타내는 그래프.FIG. 15 shows copolymers of grafted acrylic acid in a 0.4 wt% -kaolin suspension at pH 4.4 (viscosity average molecular weight

_{v): A l -1 = 3.18} × 10 5, A 1 -2 = 3.52 × 10 5, A 1 -4 = 4.35 × 10 5 a graph showing the sedimentation rate of the amount of).

v) : A_l-1=3.18×10⁵, A₁-2=3.52×10⁵, A₁-4=4.35×10⁵)의 첨가량에 대한 투과도를 나타내는 그래프.FIG. 16 shows copolymers of grafted acrylic acid in a 0.4 wt% kaolin suspension at pH 4.4 (viscosity average molecular weight

v): A _l -1 = 3.18 x 10 ⁵ , A ₁ -2 = 3.52 x 10 ⁵ , A ₁ -4 = 4.35 x 10 ⁵ ) A graph showing the permeability with respect to the addition amount.

FIG. 17 is similar to FIG. 15, with a pH value of 9.7.

FIG. 18 is similar to FIG. 16, with a pH value of 9.7.

v) : A₂-1=3.48×10⁵, A₂-2=3.68×10⁵, A₂-4=4.12×10⁵의 첨가량에 대한 침강속도를 나타내는 그래프.19 shows copolymer coagulants grafted with acrylamide in a 4 wt% kaolin suspension at pH 3.8 (viscosity average molecular weight

v): Graph showing sedimentation rate with respect to the amount of A ₂ -1 = 3.48 × 10 ⁵ , A ₂ -2 = 3.68 × 10 ⁵ , and A ₂ -4 = 4.12 × 10 ⁵ .

v) : A₂-1=3.48×10⁵, A₂-2=3.68×10⁵, A₂-4=4.12×10⁵의 첨가량에 대한 투과도를 나타내는 그래프.FIG. 20 shows copolymer coagulants grafted with acrylamide in a 4 wt% -kaolin suspension at pH 3.8 (viscosity average molecular weight

v): A graph showing the permeability with respect to the addition amount of A ₂ -1 = 3.48 × 10 ⁵ , A ₂ -2 = 3.68 × 10 ⁵ , A ₂ -4 = 4.12 × 10 ⁵ .

The present invention relates to a novel chitosan-based copolymer flocculant, and more particularly, to a novel chitosan-based copolymer flocculant and its use exhibiting cationic and anionic amphoteric aggregation properties. Due to the development of industry and the rapid increase of population, water pollution caused by various wastewaters is not only damaging to fisheries resources, but also reaching a serious condition that can not be used as living water or industrial water. In general, the treatment method of the dispersed particles in the solution differs depending on the type and size of the particles. Precipitable suspended solids having a particle diameter of 1 μm or more can be easily removed by precipitation, but colloidal materials of 1 μm or less are not separated by filtration or precipitation. Particularly, hydrophobic colloids have surface charges, so that the surface charges are agglomerated by adding salts and the like, and the hydrophilic clade particles form a drooping layer and are kept in a stable state.

Among flocculants currently used in wastewater treatment, most of them are polyacrylamide flocculants, polyacrylic acid flocculants or derivatives thereof. However, these flocculants are difficult to dissolve because they have a very large molecular weight and have a cohesive force, and the viscosity decreases to 1/3 by the molecular chain being cut by the dissolution operation by stirring, thereby degrading the performance as a flocculant. In order to solve such disadvantages, flocculants such as starch-acrylamide copolymers and cellulose-acrylamide copolymers having a relatively low molecular weight and superior effects than those of flocculants such as polyacrylamides have been prepared. It was not economical to use, and the coagulation effect as a coagulant was also unsatisfactory.

Recently, academic research is being conducted to make functional polymer materials that can be used by modifying discarded chitin without any special use. In particular, in the study of flocculants, chitosan alone has been applied or studied, and it has not been very satisfactory for wastewater treatment.

Therefore, the applicant can easily intercalate small molecules, especially colloidal materials of 1 μm or less that cannot be separated by filtration or sedimentation because the chitin (β-chitin) present in the cuttlefish bone is arranged in parallel. It has been used to produce a new flocculant.

An object of the present invention is to synthesize chitosan and acrylic acid in the presence of ceric ammonium nitrate (CAN) as an initiator using chitosan using chitin present in bone of cuttlefish to synthesize a flocculant of polymer material that can utilize waste resources. The acrylamide is reacted to prepare a chitosan copolymer coagulant.

Another object of the present invention is the use of the obtained chitosan copolymer coagulant for wastewater treatment.

Still another object of the present invention is to prepare a new coagulant in which the cationic coagulant possessed by chitosan, polyacrylamide (PAM), and polyacrylic acid (PAA) together have both positive and anionic coagulants.

In the present invention, chitosan used as a starting material is prepared by deacetylating chitin separated from cuttlefish bone by the Hackman method by Rigby method, and the acrylic acid monomer is manufactured by Japan Hayashi Pure Chemical. Co. The primary reagent was used by distillation under reduced pressure at 40 mmHg, 66.2 ° C., and the acrylamide monomer was used after drying under reduced pressure by recrystallizing the primary reagent of the company in methanol twice.

Ceric ammonium nitrate (hereinafter referred to as "CAN"), a reaction initiator, was used in solution by dissolving 5.48 g of a first-class reagent of WaKo Company in 100 ml of 1N-HNO ₃ .

Particles used for the coagulation effect test in the present invention is Japan Hayashi Pure Chemical Co. Kaolin, a product, was dried at 100 ± 5 ° C. for 3 hours to use fine particles that passed through a 200 mesh sieve.

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

Example 1

Into a 300 ml four-necked flask equipped with nitrogen inlet tube, thermometer, stirrer, and cooler, put a certain amount of chitosan, acrylic acid monomer, and 150 ml of 15wt% -acetic acid solution in a water bath where the temperature is kept constant. Stirring for 1 hour.

After adding a certain amount of CAN solution to the stock solution, polymerization was carried out for a certain time. The obtained product was precipitated in about 10 times acetone, filtered using a glass filter, and dried under reduced pressure at 50 ° C. In order to remove the acrylic acid homopolymer contained in the dried product, the mixture was extracted by stirring with dioxane-water (volume ratio = 80:20) mixture for 4 hours, precipitated in acetone, and dried at 50 ° C. in a vacuum oven.

Polyacrylic acid was added to 160 ml of water, 83 ml of acrylic acid monomer, 0.2 g of potassium persulfate, 0.2 g of ammonium persulfate in 500 ml three-necked plaques, and then polymerized at 60 ° C. for a predetermined time, and then precipitated in acetone and dried under reduced pressure.

Example 2

250ml, device a N ₂ gas inlet tube, a thermometer, a stirrer, a condenser, four-necked flask, and the acrylic monomer, 15wt% of 4g chitosan and a predetermined amount - the N ₂ gas over the next 30 ℃ water bath was added to vinegar acid solution 150ml Swell by stirring for 1 hour while passing. 0.1 M-CAN was added to 7.87 × 10 ⁻⁵ M and reacted at 30 ° C. for 3 hours.

Distilled water was added to the obtained product to a solid content of about 5%, which was precipitated in acetone, filtered, and dried under reduced pressure at 50 ° C. In order to remove the acrylamide homopolymer contained in the dried product, the mixture was extracted by stirring with acetone-water (volume ratio = 40:60) mixture for 8 hours, precipitated in acetone, and dried under reduced pressure.

In addition, polyacrylamide was redox-polymerized at 70 ° C. for a predetermined time while injecting N ₂ gas into 20 ml of isopropyl alcohol, 180 ml of water, 20 g of acrylamide, and 0.4 g of potassium persulfate in a 300 ml four-necked flask. It precipitated in acetone and dried under reduced pressure.

Example 3-7

2 g of chitosan, CAN = 3.33 × 10 ^-3 M, l5wt% -vinegar acetic acid solution in 150 ml and the reaction of 3 hours at 30 ° C. while converting the concentration of acrylic acid to 0.093∼0.741M To prepare the grafted copolymer of the following Table l.

TABLE 1

Example 8-12

In a similar manner to Example 2, the concentration of 2 g of chitosan and CAN was constant at 7.87 × 10 ⁻⁵ M and 15 ml of 15 wt% vinegar solution, and the concentration of acrylamide was changed to 2.11 to 16.88 × 10 ⁻³ M. By reacting for 3 hours at ℃ to prepare a grafted copolymer of Table 2.

TABLE 2

The coagulants synthesized in the above examples were identified using IR spectrum. That is, in FIG. 1, in the case of chitosan (C), the amide characteristic band disappeared almost and -NH ₂ band appeared in the vicinity of 1590 cm ^-1 . In the case of polyacrylic acid (PAA), a strong absorption band of C = 0 was observed around 1700cm ^-1 , and in the case of grafted chitosan (A ₁ ), the absorption band near 1700cm ^-1 overlaps with the absorption band at 1590cm ^-1 . The phenomenon occurred and appeared as a broad band, it was confirmed that the acrylic acid was grafted to the chitosan skeleton.

In the case of polyacrylamide and grafted chitosan In the IR spectra of the polyacrylamide it has reached the appeared strong C = 0 absorption peak (Peak) at 1650cm ^-1, if the chitosan showed a strong absorption band standing 1590cm ^-1 . In the case of grafted chitosan, strong absorption peak appeared at 1650cm ^-1 , indicating that acrylamide was grafted to the chitosan polymer. The prepared flocculants obtained the weight increase rate and the graft% by the following equation.

v)를 구하였다.Where ΔW is the weight increase rate, Ø is the ratio of monomer grafted (%), Wp is the weight of the product, Wc is the initial weight of chitosan, Wg is the weight of grafted acrylic acid or acrylamide, Wa is added acrylic acid Or the weight of acrylamide. Molecular weight was measured by the following formula. In other words, 1 g / dl of chitosan and grafted chitosan in 0.2 M-acetic acid, 0.1 M-sodium chloride, and 4 M-urea in the same volume of mixed solution, and then using an Ubbelohde viscometer at an intrinsic viscosity [ η] and the viscosity average molecular weight (

v) was obtained.

v^0.71(dl/g, 25℃) ………………………………………………(3)[η] = 8.93 × 10 ^-4

v ^0.71 (dl / g, 25 ° C.). … … … … … … … … … … … … … … … … … (3)

The molecular weight of polyacrylic acid was made 0.5g / dl in 1.4-dioxane and calculated | required by the following formula.

v^0.50………………………………………………………………(4)[η] = 7.6 × 10 ^-4

v ^0.50 ... … … … … … … … … … … … … … … … … … … … … … … … (4)

v^0.37(dl/g, 30℃) ……………………………………………(5)[η] = 1.34 × 10 ^-3

v ^0.37 (dl / g, 30 ° C.). … … … … … … … … … … … … … … … … (5)

Regarding the measurement of the sedimentation rate, 25 ml of inner diameter of 17 mm and 180 mm in length are settled in a settling kaolin in a settling tube. After distilled water is added, shaken well and suspended. After shaking the sedimentation tube about 20 times strongly, set the sedimentation tube vertically and read the scale of the sedimentation interface at regular intervals to calculate the velocity of the initial constant velocity sedimentation section. In addition, in measuring the permeability of the supernatant, as in the method of measuring the sedimentation rate, after shaking the sedimentation tube about 20 times vigorously and standing vertically, the absorbance of the supernatant after standing for 10 minutes was measured using a spectrophotometer and the transmittance of distilled water was 500 at The permeability of each supernatant was obtained.

Coagulation Effect According to Coagulant Addition

3 and 4 are carried out with homopolymers of known polyacrylic acids (PAA-1 and PAA-2) having molecular weights of 4.25 × 10 ⁵ and 9.87 × 10 ⁵ , respectively, for 0.4 wt% kaolin suspension at pH 4.4 in the acidic zone. The graft copolymer (A _1-4 ) prepared in Example 5 (see Table 1) shows the coagulation effect according to the amount of coagulant added.

부터 70mg/

까지는 거의 직선적인 증가를 보여 주고 있다.In FIG. 3, the homopolymer PAA-1 having a molecular weight of 4.25 × 10 ⁵ was unable to determine the settling rate when the amount of flocculant was small and the amount of 8mg /

From 70mg /

Up to almost linear increase.

까지는 급격히 증가하다가 그 이상에서는 침강속도 증가가 둔화되어 거의 평행에 도달한다.In addition, the PAA-2 homopolymer having a molecular weight of 9.87 × 10 ⁵ can be measured in all ranges and the amount of addition was 35 mg /

The rate increases sharply, but above that, the rate of settling slows down to near parallel.

In the present invention, that is, the graft copolymer A _1-4 synthesized in Example 5 is about 1/2 of the molecular weight of the homopolymer PAA-2 and shows almost the same value as PAA-1, but the sedimentation rate is the best result. Is showing. This phenomenon not only ionizes free amino groups in chitosan to positive charges in acidic solutions, but also acts much stronger than PAA-1 or PAA-2, homopolymers without hydroxyl and carboxyl groups in the molecule. This is because the coverage ratio θ is greater than the linear structure PAA-1,2 and the charge of the coagulant adhered to the particles lowers the zeta potential value (Z).

까지는 투과도가 약간 증가하다가 그 이상에서는 서서히 감소하는 경향을 보이고 있다. 이러한 이유는 선상중합체인 응집제의 경우 분자량이 어느 한계점 이하의 경우에는 콜로이드성 분자입자에 응집제분자가 과잉 흡착되어서 오히려 친수성을 갖는 응집제입자가 분산을 초래하게 되어 투과도가 저하하기 때문이다.In FIG. 4, the homopolymer PAA-1 having a small molecular weight has a coagulant added amount of 35 mg /

Until now, the transmittance is slightly increased but above that, it tends to decrease gradually. This is because, in the case of the coagulant which is a linear polymer, when the molecular weight is below a certain threshold, the coagulant molecule is excessively adsorbed to the colloidal molecular particles, so that the coagulant particles having hydrophilicity cause dispersion and the permeability decreases.

까지는 투과도가 급속히 증가하다가 그 이상에서는 증가폭이 둔화되는 경향이 있다. 본 발명에 따른 응집제인 A₁-4의 경우에는 거의 일정하게 좋은 투과도를 보여주고 있다.In the case of PAA-2, the amount of flocculant added is 25 mg /

The transmittance tends to increase rapidly until the increase is slowed. In the case of A _1-4 , the flocculant according to the present invention, the permeability is almost constant.

의 Al₂(SO₄)₃를 첨가한 후 pH 9.7에서 응집제의 투입량을 0.8mg/

부터 180mg/

까지 변화시키면서 침강속도와 투과도를 측정한 결과를 제5도 및 6도에 나타내었다.This tendency of the coagulant PAA-2 is a PAA-l flocculant no more large molecular weight distribution by over adsorption and θ values of Rigi around within the molecule for A ₁ -4 (-NH ₃ ^+1), and the Z It seems to be because price and the like work greatly. In addition, in the alkaline region of the 0.4 wt% kaolin suspension, PAA-1, PAA-2, and A _1-4 alone did not show aggregation, and in order to increase the aggregation effect, 0.08 g /

Of Al ₂ (SO ₄ ) ₃ was added at a pH of 9.7.

From 180mg /

The results of measuring the sedimentation velocity and permeability with varying to 5 are shown in FIGS. 5 and 6.

정도 첨가했을때, 가장 좋은 침강속도를 보이고 있으며 그 이상에서는 거의 일정한 값을 보이고 있다. 또 침강속도를 PAA-1, PAA-2, A₁-4의 순이며 이러한 경향은 키토산에 그라프트된 아크릴산이 PAA-1이나 PAA-2처럼 카르복실기가 -하전으로 전리하여 분자내의 아미노기 및 수산기와 함께 강한 흡착작용을 할 뿐만 아니라 분기상 구조탓으로 피복율 θ값을 크게하기 때문인 것으로 보아진다.5 shows that the settling rate is 70 mg / g in all cases of monopolymers (PAA-1 and PAA-2) or grafted copolymers (A _1-4 ).

When it is added, it shows the best sedimentation rate and above that it shows almost constant value. The sedimentation rate is in the order of PAA-1, PAA-2, A _1-4 , and this tendency is that the acrylic acid grafted to chitosan, like PAA-1 or PAA-2, is isolated by the carboxyl group to -charge, so that amino and hydroxyl groups in the molecule It is believed that not only does it have a strong adsorption effect but also increases the coverage ratio? Due to the branched structure.

In FIG. 6, the permeability of A _1-4 was the highest, followed by PAA-2 and PAA-1. In this case, the coagulant of the homopolymer and the graft copolymer showed a significant difference in permeability. Indicates.

로 변화시키면서 침강속도와 투과율을 구한 결과를 제7도 및 8도에 나타내었다.This tendency indicates that in the alkaline region of pH 9.7, colloidal molecular particles of kaolin and Al ³⁺ first form flocculation by electrostatic attraction, and then the agglomeration forms flocculation molecules and flocculation. In the case of PAA of the linear polymer in which the functional group of the -COOH group functions, the permeability is excessively adsorbed to the dispersed particles, so that the permeability is dispersed in the suspension due to the specificity of the linear polymer. On the other hand, 4wt% - a flocculating agent (A ₂ -4) prepared in Example 10, the present inventors with respect to the kaolin suspension 0.087~87mg /

The results of determining the sedimentation velocity and transmittance while changing to are shown in FIGS. 7 and 8.

까지는 침강속도가 서서히 증가하다가 그 이상에서는 급격히 증가하는 경향을 보이고 있으며 PAM-2와 A₂-4의 경우는 응집제 첨가량이 1.0mg/

까지는 침강속도가 증가하다가 그 이상에서는 거의 일정한 값을 보이고 있다. 이러한 경항을 PAM-2에 비하여 PAM-1은 분자량이 적어서 응집제의 양이 증가할수록 침강속도가 증가하는 것으로 생각되며, 분기상 공중합체인 A₂-4의 경우는 선상중합체인 PAM-2보다 분자량은 적지만 키토산분자내의 -NH₂,-OH그룹의 흡착에 의한 응집작용에 의하여 응집효과가 좋은 결과를 나타내고 있다고 볼수 있다.In FIG. 7, the known polyacrylamide homopolymers (PAA-1 and PAM-2) having molecular weights of 3.85 × 10 ⁵ and 10.21 × 10 ⁵ and the flocculant (A _2-4 ) prepared in Example 10 were prepared. As compared with each other, in the case of PAM-l, the amount of flocculant added was 0.870 mg /

The sedimentation rate gradually increased until then, but increased rapidly above that. In the case of PAM-2 and A ₂ -4, the amount of flocculant added was 1.0 mg /

The sedimentation rate increases until then, but above that, it is almost constant. The more this tendency as compared to the PAM-2 PAM-1 can write down the molecular weight increases the amount of the flocculant is thought to increase the settling velocity, when the gaseous minutes copolymer A ₂ -4 are more linear polymer of molecular weight of PAM-2 Although small, the coagulation effect by the adsorption of -NH ₂ and -OH groups in the chitosan molecule can be said to have a good result.

이하인 저농도에서는 응집제량의 증가에 따라 투과도가 증가하다가 포화치에 도단한 다음 응집제가 대량 첨가되었을 경우에는 입자표면이 과잉 흡착상태로 되어서 폴리아크릴아미드는 입자의 분산안정제로 작용하여 다시 투과도가 낮아지는 경향이 보이고 있다. 그러나, 그라프트된 키토산의 경우는 응집제의 첨가량이 0.522mg/

까지는 증가하다가 그 이상에서는 거의 일정한 값을 나타내고 있으며, 투과도의 우선순위를 보면 그라프트된 키토산(A₂-4) ＞PAM-2＞PAM-1의 순으로 좋은 것을 알수 있다.8, in the case of polyacrylamide (PAM), the amount of flocculant is 1.0 mg /

At low concentrations below, the permeability increases with increasing amount of flocculant, but when the coagulant is added to the saturation value, when the flocculant is added in a large amount, the surface of the particles becomes excessively adsorbed, and the polyacrylamide acts as a dispersion stabilizer of the particles, thereby decreasing the permeability. Is showing. However, in the case of grafted chitosan, the amount of flocculant added was 0.522 mg /

It is increasing until then, it shows a substantially constant value, and the priority of the permeability is good in the order of grafted chitosan (A ₂ -4)>PAM-2> PAM-1.

From these results, it can be seen that the greater the molecular weight, the smaller the molecular diameter, the larger the diameter of the molecule, and the cohesive force of the branched structure with -NH ₂ , -OH group than the linear structure.

flocculation effect according to pH

0.4 wt% kaolin suspension was diluted with dilute HCl or dilute NaOH solution without changing the pH from 0.6 to 12.5 (A ₁ -0) and the coagulant (A ₁ -4) in Example 5 of the present invention. The comparison result when put in is shown in 9, 10, 11, 12 degrees.

In the acidic region of 9 and 10 degrees, there is a significant difference between the case when the flocculant and the flocculant are not added. -NH ₂ functional groups within A ₁ -4 flocculant molecules cohesive effect is significant to the -NH ₃ ⁺ the action is kaolin, colloidal particles with a negative charge because the personnel tinged represents -NH ₃ ⁺ in the acid region. In the case of the A _1-4 coagulant, the permeability is almost constant, and the sedimentation rate decreases as the neutral gets closer to neutral, but after some time, the clade particles are almost aggregated.

In the alkaline region it was not all aggregated if incorrectly loaded when loaded only coagulant A ₁ -4, by the addition of an inorganic flocculant of Al ₂ (SO _{4) 3} After forming the colloidal particles and the charge of the kaolin re-A ₁ - The flocculation agent was added only to aggregate.

넣고 A₁-4응집제를 35.7mg/

로 일정하게 하였을 때를 비교한 그래프이다.Claim 11 and also 12 turns 0.8g of Al ₂ (SO ₄₎ when the insert ₃ and Al ₂ (SO _{4) 3} /

Add A _1-4 coagulant 35.7mg /

It is a graph comparing the time when it was set as constant.

In the case of A _1-4 coagulant, the sedimentation rate was highest near pH 10 and the permeability was good. However, above pH l0, the sedimentation rate decreases rapidly and the permeability decreases. This trend is Al ₂ (SO _{4) 3} Al ₃ ⁺ charge acts as a colloidal particle dispersion, because the Al ₃ ⁺ ph is combined with OH-, which in the suspension is in the higher Al (OH) ₃ which has It is thought that the interchange is lowered and eventually the cohesive characteristics are reduced.

넣고, A₁-4응집제를 35.7mg/

넣었을 때와 Al₂(SO₄)₃만을 0.8g/

넣을을 경우가 비슷한 경향을 나타내고 있다.The transmittance of FIG. 12 is 0.8 g / Al ₂ (SO ₄ ) ₃ .

35.7 mg / L of A _1-4 coagulant

0.8 g / of Al ₂ (SO ₄ ) ₃

If you put it is showing a similar trend.

In FIG. 11, the sedimentation rate is rapidly increased up to around pH 10 and rapidly decreased above that, while the permeability of FIG. 12 gradually increases up to around pH 10 and slowly decreases above it. In addition, in the case of A ₁ = 0 without a binder, it can be seen that the pH tends to increase rather than increase.

On the other hand, 4wt% - the results of investigation of influence of the pH at the time did not put the kaolin suspension was diluted HCl aqueous solution and dilute coagulant A ₂ -4 synthesized by changing the pH from 2.4 to 11.0 with NaOH solution and the coagulant of claim 13 also And 14 degrees.

첨가하였을 경우는 pH 2.0∼3.5부근에서 응집효과가 좋은 반면 pH가 점차적으로 증가할수록 응집력이 급격히 저하되는 것을 알수 있다. 또한 제14도에 나타낸 바와 같이 응집제의 첨가량이 50mg/

정도일때 높은 pH에서는 침강속도나 투과도를 측정할 수 없으며, 500mg/

이상의 높온 농도에서 비교적 높은 응집력을 나다내고 있는 것을 알수 있다. 또한, pH가 11에서 보다 8의 경우가 더 좋은 응집효과가 있는 것으로 나타났다. 이러한 경향은 키토산 분차자체의 2번 탄소에 있는 -NH₂가 산성에서는 -NH₃ ⁺로 존재하고 있어서 정전기적 인력에 의한 흡착응집이 pH가 높아질수록 둔화되는데 기인한 것으로 보며, 그라프트된 아크릴아미드가 높은 pH에서는 이온화되어 점착에 의한 응집이 둔화되는데 기인된다고 생각된다.In the Figure 13, and see that when A ₂ -4 hayeoteul the coagulant than when no addition of coagulant added is much good cohesion, A ₂ -4 a coagulant 50mg /

When added, the cohesive effect was good at pH 2.0-3.5, but the cohesive force rapidly decreased as the pH was gradually increased. In addition, as shown in FIG. 14, the addition amount of the flocculant was 50 mg /

At high pH, no sedimentation rate or permeability can be measured, and 500 mg /

It can be seen that the cohesive force is relatively high at the above high concentration. In addition, it was found that the case of 8 has a better flocculation effect than at pH 11. This tendency is attributed to the fact that -NH ₂ in the carbon number 2 of the chitosan sediment itself is -NH ₃ ⁺ in acid, so that the adsorption agglomeration by electrostatic attraction slows down as the pH increases. Is considered to be due to the ionization at a high pH to slow the aggregation due to adhesion.

Coagulation Effect According to Molecular Weight

Results of examining the cohesiveness of the graft copolymers having different molecular weights are shown in FIGS. 15, 16.17 and 18 degrees.

정도까지는 거의 직선적인 증가를 나타내다가 그 이상에서는 거의 일정한 값을 보여주고 있다. A₁-2응집제와 A₁-4응집제의 경우에는 첨가량이 증가할수록 계속적으로 완만한 증가를 보여주고 있다. 또한 제16도에서의 투과도는 모든 경우에 있어서 첨가량이 10mg/

이상에서는 95%정도의 우수한 특성을 나타내고 있다. 이러한 이유는 분기상 구조를 갖는 그라프트 공중합체의 분자거동에 의한 응집특성은 분자량의 크기에 따라 침강속도가 차이가 나지만 응집제첨가 l0분후에 측정한 응집특성에는 별다른 영향을 나타내지 않는 것으로 보인다.As shown in FIG. 15, in the acidic region of pH 4.4, the sedimentation rate of the A ₁ -1 coagulant having the smallest molecular weight was the slowest and the addition amount was 10 mg / g.

To the extent it shows a nearly linear increase and above that it shows a nearly constant value. In the case of A ₁ -2 and A ₁ -4 coagulants, the increase gradually increased as the amount added. In addition, the permeability in FIG. 16 shows that the addition amount in all cases is 10 mg /

In the above, the outstanding characteristic of about 95% is shown. For this reason, the flocculation characteristics of the graft copolymer having a branched structure due to the molecular behavior of the sedimentation rate is different depending on the size of the molecular weight, but it does not seem to have a significant effect on the flocculation characteristics measured after the addition of flocculant 10 minutes.

를 첨가할때까지는 급격한 증가를 보이다가 그 이상에서는 거의 평형에 도달하였다.In the case of claim 17, whereas in the alkaline region of 18 degrees to help _{pH 9.7 A l -l, A 1} -2 coagulant addition amount is more increased indicating a rapid increase, A ₁ -4 coagulant is 50mg /

The addition increased sharply until, and nearly reached equilibrium.

Also in FIG. 18, results similar to those in FIG. This tendency is consistent with Noda's theory that when the same amount of water-soluble coagulant having different molecular weights is added, the larger the molecular weight, that is, the larger the diameter of the coagulant particle molecule, the greater the cohesive force by adsorption or adhesion by the electrostatic attraction of the functional group. Doing.

까지는 증가하다가 그 이상에서는 거의 변화가 없으며, 합성한 응집제의 분자량이 큰 A₂-4응집제의 경우가 A₂-1, A₂-2응집제 보다 우수한 응집력을 나타내고 있어 알수 있다.On the other hand, the effect of the molecular weight of the grafted chitosan on the sedimentation rate or permeability of the supernatant is shown in Figure 19 and 20 degrees. For A ₂ -1, A ₂ -2 coagulant, as shown in Figure 19, but increased as the concentration of the coagulant increased in the case of A ₂ -4 coagulant the concentration of the coagulant 1.0mg /

By increasing while we can see here above in no little change, in the case of the large molecular weight of the synthetic flocculant A ₂ -4 aggregating agent exhibit excellent cohesive than A ₂ -1, A ₂ -2 coagulant.

In addition, as shown in FIG. 20, as the concentration of all the coagulant synthesized increases, the permeation rate is almost unchanged. The A _2-4 coagulant having a high molecular weight shows the best coagulation effect. This result is also consistent with the above nodiron.

As described above, the polymer coagulant can be prepared using chitin that has been discarded without any special use, and the coagulant can be used for wastewater treatment to have a considerable effect. Those skilled in the art will appreciate that the invention is not limited to the claims and there will be many variations.

Claims (4)

A chitosan copolymer coagulant obtained by graft copolymerizing acrylic acid or acrylamide to chitosan in the presence of ceric ammonium nitrate as an initiator. The chitosan copolymer coagulant according to claim 1, wherein the coagulant has a viscosity average molecular weight of 3.17 to 4.42 x 10 ⁵ . The chitosan copolymer coagulant according to claim 1, wherein the reaction temperature is 30 to 55 ° C. A method of using a flocculant using the chitosan copolymer coagulant obtained in claim 1 for wastewater treatment.

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