니켈 프탈로시아닌 염료 수용액의 전오존처리 및 흡착특성

배영한, 양종규*, 최정균*, 이성식

동아대학교 화학공학과

부산정보대학 환경화학계열*

Pre-ozonation and Adsorption Characteristics of Nickel Phthalocyanine Dye aqueous Solution

Young-Han Bae, Jong-Gyu Yang*, Jung-Gyun Choi*, Sung-Sik Lee

Department of Chemical Engineering. Dong-A University.

Dept. of Envir. & Chemi., Pusan College of Information Technology*

840 Hadan 2-dong, Saha-Gu, Pusan, KOREA

INTRODUCTION

Intensive industrial development without efficient wastewater and emission controls to protect the environment may lead to the accumulation of high amounts of heavy metals in water and soil. Metallophthalocyanine dyes exhibit properties such as superior light and wash-fastness but is highly toxic. Thus, the removal and recovery of nickel phthalocyanine (NiPc) from wastewater are important problems, due to the difficulty in treating them by the usual method. Especially, efficient adsorption of nickel ion and organic from NiPc dye solution may be conditional on a cooperative effect of various parameters, namely a physical and chemical properties of the molecule itself, interaction of the central nickel ion with the surrounding organic of the phthalocyanine molecule, and between ion-exchanger and adsorbates.

In this present work, from this point of view, the effective removal of nickel and organic from NiPc dye solution was investigated by adsorption method with various adsorbents. And the effect of pre-ozonation on adsorbability was studied.

2. EXPERIMENTAL

2.1. Material

Fig 1. The structure of nickel

phthalocyanine

Anion exchange resin of styrene system (AES) by Mitsubishi Chemie, strong basic anion exchange resin (SBA) by Mitsubishi Chemie, high silica zeolite (HSZ) by Toyo Chemie and granular activated carbon (GAC) by Calgon Ltd were used as adsorbent.

Nickel(Ⅱ) phthalocyanine tetrasulfonic acid tetrasodium salt which is produced by Fluka Chemie AG.(CH-9470 Buchs) was employed as adsorbate(Figure 1). And they were used without further purification.

2.2. Experimental

The equilibrium amounts adsorbed were determined by the so-called batch bottle technique and the concentration decay curves were obtained with a baffle basket agitator at 298K(Figure 2). For both experiments, total organic carbon analyzer (TOC, Model SHIMADZU TOC-5000) and atomic absorption spectrophotometer (AA, Model SHIMADZU, AA-6501F) determined the concentrations of total organic carbon (TOC) and metal ion. respectively.

Fig. 2. Scheme of experimental apparatus.

a: baffle b: basket c: paddle d: shaft

e: constant temperature batch f: ozonizer

Ozone was produced from an laboratory ozonizer (Model-OKANO WORKS. LTD-70530) is using air compressor.  The ozone-air mixture was introduced into reactor with NiPc dye aqueous solution through a 100-mash diffuser.

At desired time intervals (30min/L -solution), adsorbent after weighting was contacted with the pre-ozonated NiPc solution and The initial concentration of dissolved ozone was determined by the indigo blue method.

3. RESULTS AND DISCUSSION

3.1. Adsorption isotherms study

Figure 3 shows the relation between qe and Ni0 in NiPc and the adsorption capacity for nickel and TOC in dye wastewater onto various adsorbents.

Fig 3. Relation between amount adsorbed,

qe, and initial concentration CNi,o of

nickel in aqueous solution

From these constant value, the maximum adsorption capacities the adsorbents were evaluated as qmax = 2.3110, 1.7283, 1.3141 and 0.8100 [mg/g] for AES, SBA, HSZ and GAC, respectively. Preliminary experimental results showed that AES has superior simultaneous adsorptibility. But, GAC has little.

Frequently certain physical and chemical properties of compounds change upon ionization, which are related to pH. And this can affect adsorbability. Because the effect of ionization decrease as compounds become more complex. Therefore the change of pH is quite important.

Adsorption isotherm of nickel ion and TOC on AES was studied with varying pH values to determine the optimum pH range for their removal.  As the result, Figure 4 shown that the adsorbability of TOC and nickel in getting increase as pH value approach to pH 4.2 and pH 10.0, respectively.

Those pH change can not affect metal but TOC in NiPc dye. Because the structure of phthalocyanine dyes as neutral Hemoglobin is stable and is fixed the metals in the center of the structure.

Fig. 4. Adsorption isotherms of nickel ion and organic in NiPc with and without ozonation

3.2. Kinetics study

Figures 5 showed that the decay curve of nickel ion and TOC in NiPc dye solution by AES. From those figures, we obtained that the kinetic parameters on the AES with varying pH values and the results on the effective diffusivity for nickel ion and TOC in NiPC dye aqueous solution on AES system expressed in the form of De=1.76×exp[0.73×qe] and De=2.37×exp[0.04×qe].  It became clear that the diffusion was AES changed depending on the amount adsorbed.

Fig.4. The simultaneous decay curves of nickel and TOC in nickel phthalocyanine

dye solution on AES with and without pre-ozonation.

Open symbol : with pre-ozonation  Closed symbol : without pre-ozonation

4. CONCLUSIONS

The adsorption characteristics of NiPc dye solution and the effect of ozone on adsorbability were studied. From the decay curves and equilibrium data, equilibrium and kinetic parameters were determined.

1. The results show that anion exchange styrene system resin (AES) is a potential        adsorbent for nickel ion and TOC in NiPc dye solution.

2. The adsorption isotherms of NiPc dye solution are good fit to the Freundlich         and Toth isotherm equation.

3. The effective diffusivity(De) for nickel and TOC of NiPc is respectively 1.68         to 1.98 and 1.78 to 3.32 in range of pH6 to 10

4. Pre-ozonation can increase the adsortivity of nickel ion and organic.

5. LITERATURE CITED

1. Gworek, B. Environ. Pollut. 75, 269

2. J. Hoigne, and H. Bader, "Determination of Ozone in Water by the Indigo           Method: A Submitted Method", Ozone Sci.Eng, 4, 169 (1982)

3. S. S Lee, M. H Yu, K. C. Choi, D. U Choi, "Removal of Copper in Copper        Phthalocyanine Dye Solution by the Chelate Resin Particles", Korean Society of       Environ. Eng., 19, 12 (1997).

4. 東 國 茂, 染料含有排水□水環境□□影響, 水環境學會誌, Vol.20, No.4,2-6         (1997)