A CNT-TiO2 nano composite was prepared from titanium chloride (TiCl4) via sol-gel process using multi walled carbon nano tube (MWCNT) followed by calcination at 450℃. Spectral analysis revealed that the formed TiO2 resided on the carbon in anatase form. The effect of adsorption was investigated using aqueous solution of methylene blue and procion blue dye. The photochemical reaction of CNT-TiO2 composite in aqueous suspensions was studied under UV illumination in batch process. The reaction was investigated by monitoring the discoloration of the dyes employing UV-Visible spectro-photometeric technique as a function of irradiation time. The catalyst composites were found to be efficient for the photodegradation of the dye.

In order to investigate the effect of doping C, N, B and F elements on TiO2 for reducing the band gap, the heat treatment of TiO2 was carried out with tetraethylammonium tetrafluoroborate. Through XRD and XPS analysis, the C, N, B and F doped anatase TiO2 was confirmed. According to the increase of temperature during treatment, the particle size was increased due to aggregation of TiO2 with elements (B, C, N and F). To investigate the capacity of photocatalyst for degradation of dye under solar light, the degradation of acridine orange and methylene blue was conducted. The degradation of dyes was carried out successfully under solar light indicating the effect of doping elements (B, C, N and F) on TiO2 for reducing the band gap effectively.

The ability of cow dung ash without any pretreatment to remove color from textile dyes N Blue RGB, Green B and EOSIN YWS from aqueous solution has been investigated in this work. Cow dung ash, an ecofriendly and low cost adsorbent was prepared by burning cow dung cakes in the muffle furnace at 500℃. The adsorption was achieved under different pH and adsorbate concentration. The data was fitted to simple polynomial and the isotherms similar to Langmuir and Freundlich isotherms.

The use of low cost and ecofriendly adsorbent has been investigated as an alternative to the current expensive method of removing dyes from wastewater. Cow dung cakes were collected from the nearby village which was burnt in a muffle furnace at 500℃ to obtain the required ash. This paper deals with the removal of Reactive Blue 221, Acidoll Yellow 2GNL and Olive BGL which are mainly used in textile industry, from aqueous solution by cow dung ash without any pretreatment. The adsorption was achieved under different pH, adsorbate concentration and the applicability of Langmuir and Freundlich isotherms were examined.

This study was carried out to propose a simple method for the extraction of seven tar dyes such as tartrazine, sunset yellow FCF, amaranth, erythrosine, allura red, brilliant blue FCF and indigo carmine using aminopropyl amine cartridge and to determine the content of the dyes in candies, soft drinks, ice bars and okchuns produced in Korea. The tar dyes were simultaneously analyzed by reverse phase high performance liquid chromatography(HPLC). The recovery rates of the dyes ranged from 65.8% to 99.6%. The contents of the dyes in candies, soft drinks, ice bars and octhuns were N.D.-50.1 mg/kg, N.D.-49.9 mg/kg, N.D.-56.0 mg/kg and N.D.-867.3 mg/kg, respectively. The types of the dyes used most frequently for candies, soft drinks and ice bars were tartrazine, brilliant blue and amaranth, respectively. Of the samples, tartrazine was used frequently, and indigo carmine was not used at all.

국내 화장품 업계에서 실제 사용되고 있는 합성타르색소인 적색204호, 적색215호, 등색203호의 3가지 색소에 대하여 유전독성시험을 행하였다. Chinese hamster lung(CHL) 세포에서의 염 색체이상시험과 ddY마우스를 이용한 소핵시험 및 초파리 날개를 이용한 체세포돌연변이 재조합 시험을 실시하였다. 그 결과 염색체이상시험과 소핵시험에서는 적색204호, 적색215호, 등색203호에서는 유전독성을 나타내는 변이원으로서는 작용하지 않는 것으로 나타났고 초파리날개를 이용한 체세포돌연변이시험에서는 각각 100 ㎎/㎖에서 single small spot의 출현빈도가 p<0.05의 유의수준에서 대조군에 비해 증가양상을 보였고, twin spot의 빈도 수는 적색204호의 경우는 50 ㎎/㎖ 농도에서, 적색215호의 경우는 100 ㎎/㎖ 농도에서 p<0.05의 유의수준에서 증가양상을 보여 약한 돌연변이원성을 나타내었다.

The green synthesis of inorganic nanoparticles (NPs) using biomaterials has garnered considerable attention in recent years because of its eco-friendly, non-toxic, simple, and low-cost nature. In this study, we synthesized NPs of noble metals, such as Ag and Au using an aqueous extract of a marine seaweed, Ecklonia cava. The formation of AgNPs and AuNPs was confirmed by the presence of surface plasmon resonance peaks in UV-Vis absorption spectra at approximately 430 and 530 nm, respectively. Various properties of the NPs were evaluated using characterization techniques, such as dynamic light scattering, transmission electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis. Phytochemicals in the seaweed extract, such as phlorotannins, acted as both reducing and stabilizing agents for the growth of the NPs. The green-synthesized AgNPs and AuNPs were found to exhibit high catalytic activity for the decomposition of organic dyes, including azo dyes, methylene blue, rhodamine B, and methyl orange.

플루오레세인 구조를 갖는 잔틴계 염료의 형광안료로의 응용 가능성 및 제조되는 안료들의 광학 특성 조절 가능성을 확인하기 위하여 본 연구를 진행하였다. 안료 제조에는 수용성 잔틴계 염료인 eosin Y (D&C Red No.22), phloxine B (D&C Red No.28)를 주로 사용하였으며, 염료를 용매에 용해시켜 분체와 분산, 교반 하고 이를 건조시켜 분쇄함으로써 안료를 제조 하였고, 제조된 안료들에 대해서는 형광과 관련한 광학 특성을 측정하였다. 사용한 용매의 종류, 염료의 함량, 그리고 염료의 혼합 투입 비율에 따라서 안료의 광학적 특성이 변함을 관찰하였다. 실험 결과에 따르면, 분체에 흡착된 염료 중 일부분이 형광 발색을 하며, 나머지는 형광에 기여하지 않는 것으로 보인다. 안료를 구성하는 분체-염료계 내부의 결합 (혹은 상호작용) 세기와 그 특성을 파악하기 위한 안료 수세실험 결과, 안료 계 내에는 서로 다른 2개 이상의 상호작용이 존재하며, 그 중 하나는 용매-염료 상호작용보다 비교적 강하였다.

In this study, a metal-organic framework (MOF) material NH2-MIL-101(Fe) was synthesized using the solvothermal method, and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-visible spectrophotometry, field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and surface area measurements. The XRD pattern of the synthesized NH2-MIL-101(Fe) was similar to the previously reported patterns of MIL-101 type materials, which indicated the successful synthesis of NH2-MIL-101(Fe). The FT-IR spectrum showed the molecular structure and functional groups of the synthesized NH2-MIL-101(Fe). The UV-visible absorbance spectrum indicated that the synthesized material could be activated as a photocatalyst under visible light irradiation. FE-SEM and TEM images showed the formation of hexagonal microspindle structures in the synthesized NH2-MIL-101(Fe). Furthermore, the EDS spectrum indicated that the synthesized material consisted of Fe, N, O, and C elements. The synthesized NH2-MIL-101(Fe) was then employed as an adsorbent and photocatalyst for the removal of Indigo carmine and Rhodamine B from aqueous solutions. The initial 30 min of adsorption for Indigo carmine and Rhodamine B without light irradiation achieved removal efficiencies of 83.6% and 70.7%, respectively. The removal efficiencies thereafter gradually increased with visible light irradiation for 180 min, and the overall removal efficiencies for Indigo carmine and Rhodamine B were 94.2% and 83.5%, respectively. These results indicate that the synthesized MOF material can be effectively applied as an adsorbent and photocatalyst for the removal of dyes.

In this study, the reductive decolorization of three acid and basic dyes using modified zero-valent iron (i.e., acid-washed iron (Aw/Fe) and palladium coated iron (Pd/Fe)) at various pH conditions (pH 3 5) was experimentally investigated and the decolorization characteristics were evaluated by analyzing the absorbance spectra and reaction kinetics. In the case of acid dyes such as methyl orange and eriochrome black T, color removal efficiencies increased as initial pH of the dye solution decreased. However, the color removal of methylene blue, a basic dye, was not affected much by the initial pH and more than 70% of color was removed within 10 min. During the decolorization reaction, the absorbance of methyl orange (λmax = 464 nm) and eriochrome black T (λmax = 528 nm) decreased in the visible range but increased in the UV range. The absorbance of methylene blue (λmax = 664 nm) also decreased gradually in the visible range. Pseudo-zero order, pseudo-first order, and pseudo-second order kinetic models were used to analyze the reaction kinetics. The pseudo-second order kinetic model was found to be the best with good correlation. The decolorization reaction rate constants (k2) of methylene blue were relatively higher than those of methyl orange and eriochrome black T. The reaction rate constants of methyl orange and eriochrome black T increased with a decrease in the initial pH.