Factors and mass ratio analyses for Reactive Blue 19 dye decolorization using ozone: an experimental and analytical modelling approach / Análises de atributos e taxa mássica da descolorização do corante Azul Reativo 19 usando ozônio: modelagem experimental e analítica

ABSTRACT Dyes highly reduce sunlight penetration into the stream, and consequently affect photosynthesis and oxygen transfer into water bodies. An experimental and analytical modelling approach to Reactive Blue 19 (RB19) removal using ozone was carried out. For this purpose, factors and mass ratio analyses were assessed based on batch assays experiments. Removal efficiency increased from 64 to 94% when the dosage increased from 38.4 to 153.6 mg O3.L-1. Results showed that RB19 is more efficiently removed when initial pH is 7. The rate of RB19 removal decreased as the initial dye concentration increased. Kinetic studies showed that the ozonation of RB19 was a pseudo first-order reaction with respect to the dye, and the apparent rate constant declined logarithmically with the initial dye concentration. Mass ratio studies showed that, for the empirical analysis, the power law equation was adequate to describe mass ratio over time and the analytical analysis suggests that the process is influenced by mass transfer in the liquid film as well as in the bulk fluid.

RESUMO Os corantes reduzem significativamente a penetração da luz solar no corpo d'água e, consequentemente, afetam a fotossíntese e a transferência de oxigênio. Realizaram-se modelagens experimental e analítica da remoção do azul reativo 19 por ozônio. Para isso, avaliaram-se os atributos e a taxa mássica por ensaios em batelada. A eficiência de remoção foi de 64 para 94% quando a dose de ozônio aumentou de 38,4 para 153,6 mg O3.L-1. Os resultados mostraram que o azul reativo 19 é removido mais eficientemente em pH inicial da solução de 7. A taxa de remoção do azul reativo 19 reduziu à medida que a sua concentração inicial aumentou. Os estudos cinéticos mostraram que a ozonização do azul reativo 19 é uma reação de pseudoprimeira ordem em relação ao corante e a constante cinética aparente decai logaritmicamente com a concentração inicial de corante. A análise empírica indica que a taxa mássica ao longo do tempo pode ser descrita adequadamente por uma equação de potência, e os estudos analíticos sugerem que o processo é influenciado pela transferência de massa tanto no filme líquido quanto na massa líquida.

Synergistic activity of ofloxacin and ornidazole on biomedical fabrics against nosocomial pathogens.

Nosocomial infections in the hospitals disseminated from the cotton fabrics of health care professionals and patients leads to severe complications like respiratory, gastrointestinal and urinary tract infections. Since the hospital based textile materials like nylon and polyester has good surface properties, it can harbour large number of microorganisms. Hence in this study, two different antibacterial drugs showing synergistic properties were attached to different fabricsusing tocopherol acetate as a cross-linker with the aim that, treated fabric could act as barriers against transmission of challenge organisms. Inorder to decrease the drug resistant property of the nosocomial pathogens, a fluoroquinolone and a nitroimidazole compounds were mixed at suitable composition based on their synergistic behaviour. Both the compounds were modified to act as reactive dyes and were covalently bonded to the surface of nylon and polyester in order to impart antibacterial properties. The assay used for measuring antibacterial properties was based on the AATCC Test Method-100. The treated fabric was also subjected to multiple washings to determine its durability based on the AATCC Test Method-124. To determine the mode of action of these drugs, DNA of the drug exposed and unexposed challenge organisms were extracted and analysed by agarose gel electrophoresis. The difference in the number of viable bacteria after ‘0’ contact time and 18 hours contact time with treated fabrics were statistically calculated with P<0.05 considered significant.

Occupational Asthma Induced by the Reactive Dye Synozol Red-K 3BS

Various reactive dyes can elicit occupational asthma in exposed textile industry workers. To date, there has been no report of occupational asthma caused by the red dye Synozol Red-K 3BS (Red-K). Here, we report a 38-year-old male textile worker with occupational asthma and rhinitis induced by inhalation of Red-K. He showed positive responses to Red-K extract on skin-prick testing and serum specific IgE antibodies to Red-K-human serum albumin conjugate were detected using an enzyme-linked immunosorbent assay. A bronchoprovocation test with Red-K extract resulted in significant bronchoconstriction. These findings suggest that the inhalation of the reactive dye Red-K can induce IgE-mediated occupational asthma and rhinitis in exposed workers.

Reaction Kinetics of Monochlorotriazine Reactive Dyes with Neucleophilic Groups in Silk by High Performance Liquid Chromatography / 分析化学

Using Isopropyl amine (0.003 mol/L), p-methyl-phenol (0.03 mol/L) and methanol (1 mol/L) for simulating amino groups, phenol groups and hydroxyl groups in silk fibroin respectively, the reaction rate of different nucleophilic groups in silk with monochlorotriazine reactive dye was studied at various temperature and pH by high performance liquid chromatography. It was found that the overall reaction rate of dyes′ phenolysis was by far higher than that of ammonolysis and alcoholysis on the conditions of 70-95 ℃ and pH=8-10. The phenolysis overall reaction rates of C.I. reactive red 24 and C.I. reactive orange 2 were 8.5 and 12.5 times of their ammonolysis′, and 23 and 50 times of their alcoholysis′ in the term of pH 9 and 95 ℃. The phenolysis efficiencies of those two dyes were 47.4 and 96.3, the ammonolysis efficiencies were 4.6 and 6.9, and the isopropyl amine, p-methyl-phenol and methanol to simulate the silk fibroin, the reaction selectivity between the monochlorotriazine reactive dyes and nucleophilic groups in silk fibroin was investigated. It was deduced that monochlorotriazine reactive dyes are suitable for dyeing silk on the conditions of about 85 ℃ and pH=8-9, and under this condition, phenol groups are the major groups in silk dyeing with monochlorotriazine reactive dyes, amino groups are the minor groups, and the contributions of hydroxyl groups can be neglected.

A Case of Reactive Dye Induced Asthma in an Exposed Worker near a Dye Factory / 대한산업의학회지

OBJECTIVES: Reactive dye (RD) induced bronchial asthma is a well known form of occupational asthma. We report a case of occupational asthma due to RD in an exposed worker near a dye factory. METHODS: To evaluate the work-relatedness of bronchial asthma, we examined all possibilities by considering the working environment and performing a personal clinical survey, such as interview on the previous history of allergic diseases, clinical and immunological investigation including skin prick tests, bronchoprovocation tests, and serial peak expiratory flow rates (PEFR). RESULTS: Occupational asthma of internal origin was excluded by the characteristics of asthma, absence of occupational allergens, and negative PEFR result in the worker's own workplace. However, specific IgE and skin prick tests with reactive dye allergens were all strongly positive. RD challenge test showed maximal 34 % fall of FEV1 at 10 minutes of exposure (PD2 0: 2.11 mg/ml). CONCLUSIONS: We concluded that this case was an example of bronchial asthma by external occupational allergens. This case suggests that RD induced asthma may also occur in workers and inhabitants who have lived near a reactive dye manufacturing factory.

The prevalence of specific IgE and IgG to reactive dye-human serum albumin conjugate in workers of a dye factory and neighboring factories

Previous studies suggest that reactive dyes can induce IgE mediated bronchoconstrictions. To evaluate the significance of specific IgE and IgG antibodies in workers exposed to reactive dyes, we studied the prevalence of Black GR-specific IgG by enzyme linked immunosorbent assay, as well as Black GR-specific IgE by RAST, in 176 workers employed in 1 reactive dye factory and 4 neighboring factories. Six employees of reactive dye asthma who were working in factories near the reactive dye factories were noted. The prevalence of specific IgE antibodies in the neighboring factories was higher than in that of the reactive dye factory. The prevalence of specific IgG was highest in the reactive dye factory, and those of the neighboring factories were markedly lower. It was suggested that IgE mediated sensitization to reactive dye could have occurred in employees who were working in neighboring factories, and the prevalence of reactive dye-specific IgG antibody could be used as an in direct method of assessing the exposure of workers to reactive dye.

Health characteristics and symptom of workers in reactive dye industries / 예방의학회지

This study investigated the symptoms, medical and occupational history of 424 workers of 5 reactive dye Industries in the Inchon area in Korea. The study was performed on March 6 and July 19, 1989. The tests applied to the subjects were: serum total IgE, skin prick test with 7 inhalatory antigens, pulmonary function test, chest X-ray, methacholine test, and bronchoprovocation test. The workers were classified according to these tests into 4 groups (healthy, realitively healthy, need careful medical observation, and occupational asthma), and were compared in terms of the group characteristics and the symptom prevalence. The prevalence of occupational asthma of workers in reactive dye was 5.9%. Significant differences were observed among the 4 groups. The groups were significantly different in the variables of sex and duration of smoking among their general characteristics ; asthma, bronchitis, and other respiratory diseases with respect to their past medical history. This study suggests that we should pay special attention to the workers exposed to the risk of occupational asthma.

Reactive dye induced occupational asthma without nonspecific bronchial hyperreactivity

Current asthma is often excluded by the presence of normal bronchial hyperresponsiveness. We report two asthmatic patients with normal bronchial hyperresponsiveness and one asthmatic patient with mild bronchial hyperresponsiveness (methacholine PC20; 24 mg/ml) which was presumed to be caused by sensitization and exposure to Black GR, the most frequent sensitizer among reactive dyes. They all complained of lower respiratory symptoms after work as well as at the workstation. The bronchoprovocation test with Black GR revealed isolated immediate bronchoconstrictions in all 3 patients and all had high specific IgE antibodies to Black GR-human serum albumin conjugate. After one worker continued at work for 3 days, he experienced a marked drop of methacholine PC20, and it returned to the pre-exposure level during 1 week. The other patient whose initial methacholine challenge was negative developed bronchial hyperresponsiveness on the first day after the dye bronchoprovocation, and returned to normal bronchial hyperresponsiveness on the third day. These findings suggested that patients with occupational asthma caused by reactive dye may not always have bronchial hyperresponsiveness to methacholine, and the screening program utilizing methacholine challenges may not always identify these patients.