HONORS PROGRAM
Acid-Base Properties of Natural Adsorbents of Synthetic Dyes
Rada-Mayya Kostadinova
1. INTRODUCTION
Dyes are synthetic, water-soluble and dispersible organic compounds, which cause coloration of natural water bodies when released into the environment. They are widely used in industries such as dyestuff, textiles, rubber, leather, paper, plastics, cosmetics etc., to color their products and are invariably left in the industrial wastes. Synthetic dyes, suspended solids and dissolved organics are the main hazardous materials found in textile effluents. These materials can affect the physical and chemical properties of fresh water. In addition to the undesirable colors of textile effluents, some dyes may degrade to produce carcinogens and toxic products1. Furthermore, the colored effluents reduce light penetration and potentially prevent photosynthesis. Dyes even in very low concentrations affect the aquatic life and food chain2. Hence, the removal of dyes from process or waste effluents becomes environmentally important.
Because of the high degree of organics present in these molecules and the stability of modern dyes, conventional physicochemical and biological treatment methods are ineffective for their removal. Adsorption has been shown to be one of the most promising and extensively used methods for the removal of both inorganic and organic pollutants from contaminated water. Activated carbon is the most widely used adsorbent for this purpose because it has a high capacity for adsorption of organic matter and it is proven to be effective in treating textile wastes3. However, in view of high cost and associated problems of regeneration, there is a constant search for alternate low-cost adsorbents. Such alternatives...
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Most of the chemical based extraction processes for chitosan from grabs shells are involved with harsh chemicals with high concentration and temperature. For
Using the spectrophotometer, the absorption of each sample was measured by scanning the wavelengths. After calibrating the spectrophotometer with the blank test tube, each sample was placed into the spectrophotometer and read at 360nm. Observations were continued for each pigment sample increasing the wavelength by 20nm increments. Once these absorbance values were recorded, absorption spectra for each pigment were graphed.
In this case study, our concern goes for the chitosan nanoparticles; firstly nanoparticles are able to adsorb and/or encapsulate a drug, thus protecting it against chemical and enzymatic degradation. Furthermore the encapsulated drug may be prevented from crystallization, thus forming a solid solution. Depending on drug solubility in the carrier, a drug load varying from only a few percent up to 50%] Secondly, chitosan is ...
In this experiment, the chromatography of skittles and Crayola markers will be used to determine how the dyes that are used in the markers and candy of the same color compare to each other. By finding the chromatography of these substances, we will be able to determine whether the dyes used in these materials are the same or if they differ. We will also be able to determine if the dyes used in Crayola markers are safe to digest. My hypothesis is that the dyes used in Crayola markers and skittles of the same color will differ, but the dyes used in Crayola markers are not toxic. To better support this hypothesis, the process of chromatography and the toxicity of various dyes will need to be explained.
The latter embraced the salts of ferrous ammonium sulphate , manganous sulphate ans cobaltous sulphate. This pre-treatment process was carried out by impregnating the cellulose thiocarbonate fabric in a single metal salt solution at 30 0C for 30 min. , as described in the metathesis procedure. The pre-metallized cellulose thiocarbonate fabric was then grafted using moderate conditions included 4% MAA , 30 mmolL SPB , at 60 0C for 60 min. The results obtained are illustrated in Figure 5a-d. The data of this figure disclose (i) that the percentages graft yield (Fig. 5a) , grafting efficiency (Fig. 5b), and total conversion (Fig. 5c) enlarge by increasing the Fe2+ salt solution concentration and attain maximal at the FAS concentration corresponds to 0.2 mmol/L ; thereafter they decrease. The homopolymer (Fig. 5d) has an adverse deportment , (ii) that all polymer criteria slightly augment by heightening the Mn2+ salt solution concentration up to 0.02 mmolL ,then fall , (iii) that the Co2+ reductant ion fails to further improve the MAA grafting efficiency and graft yield. The %TC decreases by increasing the Co2+ salt solution concentration up to 0.06 mmolL , then increases. The lone prosperity of the Co2+ ion is the enhancement of MAA homopolymer
According to CSPI, Central For Science In The Public Interest, and several other resources these dyes have been linked to Cancer, Hyperactivity, and Allergic Reactions in humans. “Tests on lab animals of Blue 1, Blue 2, Green 3, Red 40, Yellow 5, and Yellow 6 showed signs of causing cancer or suffered from serious flaws, said the consumer group. Yellow 5 also caused mutations, an indication of possible carcinogenicity, in six of 11 tests.” These artificial colors were tested on lab animals and provided evidence that certain types of dyes when consumed by humans could produce harmful affects such as mutations or
Forensic analysis of dyed textile fibers. Anal Bioanal Chem. 2009Aug; 394(8):2009-18. Epub 2009 Jun 20.
Many industries like papers, textiles, gasoline, and leather are huge users of azo dyes which contains the largest group of substitute organic chemicals. The waste produced from these industries and resulting by-products have both metal ions and dyes. These waste products become hazardous when present in the surroundings. The insolvable dyes have low decomposability and only 45–47% dyes materials are known as biodegradable (Rauf and Ashraf., 2012)...
The experiment used Potassium permanganate (KMnO4), a purple substance; Potassium dichromate (K2Cr2O7), a yellow substance; and Methylene Blue, a blue substance. These substances have molecular weights, 158 g/mole, 294 g/mole and 374 g/mole. A petri dish containing agar-water gel with three wells was obtained as shown in Figure 1. Each well was labelled as potassium permanganate, potassium dichromate and methylene blue. One drop of every prepared substance was carefully placed into its respective wells in the agar-water gel using a dropper. The petri dish was immediately covered to avoid the possible effects of other foreign factors. The substances, each having specific colors, spread in the agar-water gel as shown in
All things, living or nonliving, consist of atoms and molecules. These particles are constantly in motion, and this continuous motion allows for the disbursement of molecules, or diffusion. The overall net movement of these molecules will go from areas of higher concentration, to areas of lower concentration. Therefore, following a concentration gradient (Martini). The rate of diffusion of these molecules, in accordance with Fick’s law of diffusion, is directly proportional to the concentration gradient present. However, the concentration gradient is not static and will change over time and with distance, therefore changing the rate of diffusion. It is hypothesized that the two solutions being tested, Methylene Blue and Potassium Permanganate, will begin their initial diffusion in the agar gel at a quick rate, and then progressively regress over the allotted time of 1 hour. Another factors other that will have an effect on rate of diffusion is molecular size. There is a substantial difference in molecular weight between Methylene Blue (320 g/mol) and Potassium Permanganate (158 g/mol). The combined molecules present in Potassium Permanganate are lighter than those in Methylene Blue, and therefore should allow it to diffuse more rapidly.
Kool-Aid, strawberry ice cream, and Doritos: What do these things have in common? Whether you realize it or not, many ordinary foods contain dyes. Some of the dyes are natural; others are synthetic. Is one better than the other?
This experiment demonstrated the ability of agarose gel electrophoresis to separate the mixture of dyes into their individual components by the application of a combination of dyes to the same sample well. The experiment effectively demonstrated that the dyes where different in structure, energy, and composition. Most of the dyes where negatively charged at neutral pHs and only one with positive charge. The positive charge one moved an opposite direction compared to the other dyes.
Vargas, F; & Lopez, O (2003). Natural colorants for food and nutraceutical uses. CRC Press, Boca Raton pp. 35-49, 257-277.
With the expansion of technology available to the textile industry emerged a growing want among those who produced the textiles for new colors. When this problem arose, textile producers called upon the chemistry industry to help lessen the need for textile producers to rely upon natural methods of bleaching such as sun, rain, sour milk, and urine (Britannica). While these methods had been practiced for centuries, the industry saw a definite want for a new and more efficient method of bleaching. From this point forth, chemistry’s role in the Industrial Revolution not only led to innovations in bleaching, but also led to great changes in the practice of chemistry, as we know it. In the mid-1700’s, a chemist named John Roebuck solved the problems of the textile industry with his invention of a new method for mass producing a chemical by-product known as sulfuric acid in lead chambers (Encarta 97). This discovery paved the way for sulfuric acid’s use in bleaching, and eventually led to the production of chlorine bleach, a common household product today.
...e industries, textile industries are considered as one of the major sources of wastewater in ASEAN countries. Dyes are also used in industries such as rubber, paper & pulp, dye & dye intermediate industries, pharmaceutical, tannery, food technology, hair coloring, plastic, cosmetic etc. There are more than 10,000 commercially available dyes with over 7x105 tones of dyestuff being produced annually across the world2.. The textile industry consumes more than 107 kg of dye per year of which 90% ending up on fabrics3. Of this total usage 10- 15% of the dye is lost during the dyeing process and released with the effluent. Colour is contributed by phenolic compounds such as tannins, lignins (2-3%) and organic colourants (3-4%) and with a maximum contributions from dye and dye intermediates which could be sulphur/ mordant/ reactive/ cationic/ dispersed/acid/azo vat dye4.