Search results for: anionic dyes

Authors: Harish Kuruva, Vedasri Bai Khavala, Tiju Thomas, K. Murugan, B. S. Murty

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Industries are growing day to day to increase the economy of the country. The biggest problem with industries is wastewater treatment. Releasing these wastewater directly into the river is more harmful to human life and a threat to aquatic life. These industrial effluents contain many dissolved solids, organic/inorganic compounds, salts, toxic metals, etc. Phenols, pesticides, dioxins, herbicides, pharmaceuticals, and textile dyes were the types of industrial effluents and more challenging to degrade eco-friendly. So many advanced techniques like electrochemical, oxidation process, and valorization have been applied for industrial wastewater treatment, but these are not cost-effective. Industrial effluent degradation is complicated compared to commercially available pollutants (dyes) like methylene blue, methylene orange, rhodamine B, etc. TiO₂ is one of the widely used photocatalysts which can degrade organic compounds using solar light and moisture available in the environment (organic compounds converted to CO₂ and H₂O). TiO₂ is widely studied in photocatalysis because of its low cost, non-toxic, high availability, and chemically and physically stable in the atmosphere. This study mainly focused on valorizing the mineralogical product TiO₂ (IREL, India). This mineralogical graded TiO₂ was characterized and compared with its structural and photocatalytic properties (industrial effluent degradation) with the commercially available Degussa P-25 TiO₂. It was testified that this mineralogical TiO₂ has the best photocatalytic properties (particle shape - spherical, size - 30±5 nm, surface area - 98.19 m²/g, bandgap - 3.2 eV, phase - 95% anatase, and 5% rutile). The industrial effluent was characterized by TDS (total dissolved solids), ICP-OES (inductively coupled plasma – optical emission spectroscopy), CHNS (Carbon, Hydrogen, Nitrogen, and sulfur) analyzer, and FT-IR (fourier-transform infrared spectroscopy). It was observed that it contains high sulfur (S=11.37±0.15%), organic compounds (C=4±0.1%, H=70.25±0.1%, N=10±0.1%), heavy metals, and other dissolved solids (60 g/L). However, the organo-sulfur industrial effluent was degraded by photocatalysis with the industrial mineralogical product TiO₂. In this study, the industrial effluent pH value (2.5 to 10), catalyst concentration (50 to 150 mg) were varied, and effluent concentration (0.5 Abs) and light exposure time (2 h) were maintained constant. The best degradation is about 80% of industrial effluent was achieved at pH 5 with a concentration of 150 mg - TiO₂. The FT-IR results and CHNS analyzer confirmed that the sulfur and organic compounds were degraded.

Keywords: wastewater treatment, industrial mineralogical product TiO₂, photocatalysis, organo-sulfur industrial effluent

Procedia PDF Downloads 87

Authors: Eun Ju Park, Wendy Rusli, He Tao, Alexander M. Van Herk, Sanggu Kim

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Hollow micro-/nano- structured materials have proven to be promising in wide range of applications, such as catalysis, drug delivery and controlled release, biotechnology, and personal and consumer care. Hollow sphere structures can be obtained through various templating approaches; colloid templates, emulsion templates, multi-surfactant templates, and single crystal templates. Vesicles are generally the self-directed assemblies of amphiphilic molecules including cationic, anionic, and cationic surfactants in aqueous solutions. The directed silica capsule formations were performed at the surface of dioctadecyldimethylammoniumbromide(DODAB) bilayer vesicles as soft template. The size of DODAB bilayer vesicles could be tuned by extrusion of a preheated dispersion of DODAB. The synthesized hollow silica particles were characterized by conventional TEM, cryo-TEM and SEM to determine the morphology and structure of particles and dynamic light scattering (DLS) method to measure the particle size and particle size distribution.

Keywords: characterization, DODAB, hollow silica particle, synthesis, vesicle

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Authors: V. Sivasubramanian, M. Jerold

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The advancement of adsorption is the development of nano-biocomposite for the sorption dyes and heavy metal ions. In fact, Nanoscale zerovalent iron (NZVI) is cost-effective reducing agent and a most reliable biosorbent for the dye biosorption. In this study, nano zero valent iron Sargassum swartzii (nZVI-SS) biocomposite, a novel marine algal based biosorbent, was used for the removal of simulated crystal violet (CV) in batch mode of operation. The Box-Behnen design (BBD) experimental results revealed the biosoprtion was maximum at pH 7.5, biosorbent dosage 0.1 g/L and initial CV concentration of 100 mg/L. Therefore, the result implies that nZVI-SS biocomposite is a cheap and most promising biosorbent for the removal of CV from wastewater.

Keywords: algae, biosorption, zero-valent, dye, waste water

Procedia PDF Downloads 206

Authors: Chand Pasha

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A Simple, accurate and precise spectrophotometric method for the quantitative analysis of determination of 5-aminosalicylic acid is described. This method is based on the reaction of 5-aminosalicylic acid with nitrite in acid medium to form diazonium ion, which is coupled with acetylacetone in basic medium to form azo dyes, which shows absorption maxima at 470 nm. The method obeys Beer’s law in the concentration range of 0.5-11.2 gml-1 of 5-aminosalicylic acid with acetylacetone. The molar absorptivity and Sandell’s sensitivity of 5-aminosalicylic acid -acetylacetone azo dye is 2.672 ×104 lmol-1cm-1, 5.731 × 10-3 gcm-2 respectively. The dye formed is stable for 10 hrs. The optimum reaction conditions and other analytical parameters are evaluated. Interference due to foreign organic compounds have been investigated. The method has been successfully applied to the determination of 5-aminosalicylic acid in pharmaceutical samples.

Keywords: spectrophotometry, diazotization, mesalazine, nitrite, acetylacetone

Procedia PDF Downloads 154

Authors: Reena Aggarwal

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The use of textile chemicals in the various pre and post-textile manufacturing processes has made the textile industry conscious of its negative contribution to environmental pollution. Popular environmentally friendly fibers such as recycled polyester and organic cotton have been now increasingly used by fabrics and apparel manufacturers. However, after these textiles or the finished apparel are manufactured, they have to be dyed in the same chemical dyes that are harmful and toxic to the environment. Dyeing is a major area of concern for the environment as well as for people who have chemical sensitivities as it may cause nausea, breathing difficulties, seizures, etc. Ayurvastra or herbal medical textiles are one step ahead of the organic lifestyle, which supports the core concept of holistic well-being and also eliminates the impact of harmful chemicals and pesticides. There is a wide range of herbs that can be used not only for dyeing but also for providing medicinal properties to the textiles like antibacterial, antifungal, antiseptic, antidepressant and for treating insomnia, skin diseases, etc. The concept of herbal dyeing of fabric is to manifest herbal essence in every aspect of clothing, i.e., from production to end-use, additionally to eliminate the impact of harmful chemical dyes and chemicals which are known to result in problems like skin rashes, headache, trouble concentrating, nausea, diarrhea, fatigue, muscle and joint pain, dizziness, difficulty breathing, irregular heartbeat and seizures. Herbal dyeing or finishing on textiles will give an extra edge to the textiles as it adds an extra function to the fabric. The herbal extracts can be applied to the textiles by a simple process like the pad dry cure method and mainly acts on the human body through the skin for aiding in the treatment of disease or managing the medical condition through its herbal properties. This paper, therefore, delves into producing Ayurvastra, which is a perfect amalgamation of cloth and wellness. The aim of the paper is to design and create herbal disposable and non-disposable medical textile products acting mainly topically (through the skin) for providing medicinal properties/managing medical conditions. Keeping that in mind, a range of antifungal socks and antibacterial napkins treated with turmeric and aloe vera were developed, which are recommended for the treatment of fungal and bacterial infections, respectively. Both Herbal Antifungal socks and Antibacterial napkins have proved to be efficient enough in managing and treating fungal and bacterial infections of the skin, respectively.

Keywords: ayurvastra, ayurveda, herbal, pandemic, sustainable

Procedia PDF Downloads 100

Authors: Salah A. Al-Garyani, Yousef Swesi

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Gas hydrates can be hazardous to upstream operations. On the other hand, the high gas storage capacity of hydrate may be utilized for natural gas storage and transport. Research on the promotion of hydrate formation, as related to natural gas storage and transport, has received relatively little attention. The primary objective of this study is to gain a better understanding of the effects of ionic surfactants, particularly their molecular structures and concentration, on the formation of tetrahydrofuran (THF) hydrate, which is often used as a model hydrate former for screening hydrate promoters or inhibitors. The surfactants studied were sodium n-dodecyl sulfate (SDS), sodium n-hexadecyl sulfate (SHS). Our results show that, at concentrations below the solubility limit, the induction time decreases with increasing surfactant concentration. At concentrations near or above the solubility, however, the surfactant concentration no longer has any effect on the induction time. These observations suggest that the effect of surfactant on THF hydrate formation is associated with surfactant monomers, not the formation of micelle as previously reported. The lowest induction time (141.25 ± 21 s, n = 4) was observed in a solution containing 7.5 mM SDS. The induction time decreases by a factor of three at concentrations near or above the solubility, compared to that without surfactant.

Keywords: tetrahydrofuran, hydrate, surfactant, induction time, monomers, micelle

Procedia PDF Downloads 384

Authors: Amira M. Hassanein, Nehal A. Salahuddin, Atsunori Matsuda, Toshiaki Hattori, Mona N. Elfiky

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New insights into the design of highly sensitive, carbon-based electrochemical sensors are presented in this work. This was achieved by exploring the interesting properties of conductive (Mg/Al) layered double hydroxide- Dodecyl Sulphate/Polypyrrole nanocomposites which were synthesized by in-situ polymerization of pyrrole during the assembly of (Mg/Al) layered double hydroxide, and by employing the anionic surfactant Dodecyl sulphate as a modifier. The morphology and surface area of the nanocomposites changed with the percentage of Pyrrole. Under optimal conditions, the modified carbon paste electrode successfully achieved detection limits of 0.057 and 0.134 nmol.L-1 of Terazosin hydrochloride in pharmaceutical formulation and spiked human serum fluid, respectively. Moreover, the sensors are highly stable, reusable, and free from interference by other commonly present excipients in drug formulations.

Keywords: layered double hydroxide, polypyrrole, terazosin hydrochloride, square-wave adsorptive anodic stripping voltammetry

Procedia PDF Downloads 191

Authors: R. Ahmadi, A. Khodadadi, M. Abdollahi

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The removal of copper from a dilute synthetic wastewater (10 mg/L) was studied by ion flotation at laboratory scale. Anionic sodium dodecyl sulfate (SDS) was used as a collector and ethanol as a frother. Different parameters such as pH, collector and frother concentrations, foam height and bubble size distribution (multi bubble ion flotation) were tested to determine the optimum flotation conditions in a Denver type flotation machine. To see into the effect of bubbles size distribution in this paper, a nano-micro bubble generator was designed. The nano and microbubbles that are generated in this way were combined with normal size bubbles generated mechanically. Under the optimum conditions (concentration of SDS: 192mg/l, ethanol: 0.5%v/v, pH value: 4 and froth height=12.5 cm) the best removal obtained for the system Cu/SDS with a dry foam (water recovery: 15.5%) was 85.6%. Coalescence of nano-microbubbles with bubbles of normal size belonging to mechanical flotation cell improved the removal of Cu to a maximum floatability of 92.8% and reduced the water recovery to a 13.1%.The flotation time decreased considerably at 37.5% when the multi bubble ion flotation was used.

Keywords: froth flotation, copper, water treatment, optimization, recycling

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Authors: G. Hodaifa, J. A. Páez, C. Agabo, E. Ramos, J. C. Gutiérrez, A. Rosal

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Currently, the continuous two-phase decanter process used for olive oil production is the more internationally widespread. The wastewaters generated from this industry (OMW) is a real environmental problem because of its high organic load. Among proposed treatments for these wastewaters, the advanced oxidation technologies (Fenton process, ozone, photoFenton, etc.) are the most favourable. The direct application of these processes is somewhat expensive. Therefore, the application of a previous stage based on a flocculation-sedimentation operation is of high importance. In this research five commercial flocculants (three cationic, and two anionic) have been used to achieve the separation of phases (liquid clarified-sludge). For each flocculant, different concentrations (0-1000 mg/L) have been studied. In these experiments, sludge volume formed over time and the final water quality were determined. The final removal percentages of total phenols (11.3-25.1%), COD (5.6-20.4%), total carbon (2.3-26.5%), total organic carbon (1.50-23.8%), total nitrogen (1.45-24.8%), and turbidity (27.9-61.4%) were obtained. Also, the variation on the electric conductivity reduction percentage (1-8%) was determined. Finally, the best flocculants with highest removal percentages have been determined (QG2001 and Flocudex CS49).

Keywords: flocculants, flocculation, olive oil mill wastewater, water quality

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Authors: Chand Pasha, Yasser Turki Alharbi, Krasamira Stancheva

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A simple spectrophotometric method for the determination of folic acid in pharmaceutical dosage samples was developed. The method is based on the diazotization reaction of thiourea with sodium nitrite in acidic medium yields diazonium compounds, which is then coupled with folic acid in basic medium yields yellow coloured azo dyes. Beer’s Lamberts law is observed in the range 0.5 – 16.2 μgmL-1 at a maximum wavelength of 416nm. The molar absorbtivity, sandells sensitivity, linear regression equation and detection limit and quantitation limit were found to be 5.695×104 L mol-1cm-1, 7.752×10-3 g cm-2, y= 0.092x - 0.018, 0.687 g mL-1 and 2.083 g mL-1. This method successfully determined Folate in Pharmaceutical formulations.

Keywords: folic acid determination, spectrophotometry, diazotization, thiourea, pharmaceutical dosage samples

Procedia PDF Downloads 38

Authors: Ticiane Rossi, Maurício C. Araújo, José O. Brito, Harold S. Freeman

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Natural dyes are gaining interest due their expected low risk to human health and to the environment. In this study, the wash fastness of a natural coloring matter from the liquid waste produced in the steam treatment of eucalyptus wood in textile fabrics was investigated. Specifically, eucalyptus wood extract was used to dye cotton, nylon and wool in an exhaust dyeing process without the addition of the traditional mordanting agents and then submitted to wash fastness analysis. The resulting dyed fabrics were evaluated for color fastness. It was found that wash fastness of dyed fabrics was very good to cotton and excellent to nylon and wool.

Keywords: eucalyptus, natural dye, textile fibers, wash fastness

Procedia PDF Downloads 583

Authors: A. Kesraoui, M. Seffen

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Applications of adsorption onto activated carbon for water treatment are well known. The process has been demonstrated to be widely effective for removing dissolved organic substances from wastewaters, but this treatment has a major drawback is the high operating cost. The main goal of our research work is to improve the retention capacity of Tunisian biomass for the depollution of industrial wastewater and retention of pollutants considered toxic. The biosorption process is based on the retention of molecules and ions onto a solid surface composed of biological materials. The evaluation of the potential use of these materials is important to propose as an alternative to the adsorption process generally expensive, used to remove organic compounds. Indeed, these materials are very abundant in nature and are low cost. Certainly, the biosorption process is effective to remove the pollutants, but it presents a slow kinetics. The improvement of the biosorption rates is a challenge to make this process competitive with respect to oxidation and adsorption onto lignocellulosic fibers. In this context, the alternating current appears as a new alternative, original and a very interesting phenomenon in the acceleration of chemical reactions. Our main goal is to increase the retention acceleration of dyes (indigo carmine, methylene blue) and phenol by using a new alternative: alternating current. The adsorption experiments have been performed in a batch reactor by adding some of the adsorbents in 150 mL of pollutants solution with the desired concentration and pH. The electrical part of the mounting comprises a current source which delivers an alternating current voltage of 2 to 15 V. It is connected to a voltmeter that allows us to read the voltage. In a 150 mL capacity cell, we plunged two zinc electrodes and the distance between two Zinc electrodes has been 4 cm. Thanks to alternating current, we have succeeded to improve the performance of activated carbon by increasing the speed of the indigo carmine adsorption process and reducing the treatment time. On the other hand, we have studied the influence of the alternating current on the biosorption rate of methylene blue onto Luffa cylindrica fibers and the hybrid material (Luffa cylindrica-ZnO). The results showed that the alternating current accelerated the biosorption rate of methylene blue onto the Luffa cylindrica and the Luffa cylindrica-ZnO hybrid material and increased the adsorbed amount of methylene blue on both adsorbents. In order to improve the removal of phenol, we performed the coupling between the alternating current and the biosorption onto two adsorbents: Luffa cylindrica and the hybrid material (Luffa cylindrica-ZnO). In fact, the alternating current has succeeded to improve the performance of adsorbents by increasing the speed of the adsorption process and the adsorption capacity and reduce the processing time.

Keywords: adsorption, alternating current, dyes, modeling

Procedia PDF Downloads 127

Authors: Samen Boota, Arslan Ishaq

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More than 4 billion tons of chicken feathers are wasted yearly worldwide which is not environmental friendly. In order to make use of these 4 billion tons of feathers it is necessary to incorporate them to the textile materials. The main objective of this study is to develop the winter wears with improved thermal comfort and mechanical properties. Chick feathers were blended with cotton fibers to spin them into yarn, weave them dye them using reactive dyes. The developed fabric was tested for thermal comfort, tensile and tears strength. The results were also compared with pure cotton fabric of similar GSM. It is observed from the results that chicken feathers and cotton blended fabric was improved thermal comfort and mechanical properties.

Keywords: Alambeta, compatibilizing, permeability, sliver

Procedia PDF Downloads 312

Authors: María Rojo Granados

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This work presents an empirical investigation of the performance of pink and purple petunia petals and orange and red geranium petals on a linen fabric using the Eco Print technique. This theoretical and practical approach represents an advance in the textile world towards sustainable dyeing and printing methods. It is understood that the possibility of mass printing or dyeing through these methods in fashion is complex, but it can be an approach toward a more sustainable industry. The research consists of twenty-two empirical tests where different processes and methods are applied and explained at different temperatures and using different mordants. The test results allow the selection of which printing and dyeing methods can be applied to the fashion industry in an environmentally consistent way.

Keywords: dyeing, empirical tests, petals, performance, printing, sustainably

Procedia PDF Downloads 69

Authors: Yu-Ting Chen, Shiao-Shing Chen, Hung-Te Hsu, Saikat Sinha Ray

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Forward osmosis (FO) is a crucial technology with low operating pressure and cost for water reuse and reclamation. In Taiwan, with the advance of science and technology, thin film transistor liquid crystal displays (TFT-LCD) based industries are growing exponentially. In the optoelectronic industry wastewater, the iodide is one of the valuable element; it is also used in the medical industry. In this study, it was intended to concentrate iodide by utilizing FO system and can be reused for TFT-LCD production. Cellulose triacetate (CTA) membranes were used for all these FO experiments, and potassium iodide solution was used as the feed solution. It has been found that EDTA-2Na as draw solution at pH 8 produced high water flux and minimized salt leakage. The result also demonstrated that EDTA-2Na of concentration 0.6M could achieve the highest water flux (6.69L/m2 h). Additionally, from the recovered iodide ion from pH 3-8, the I- species was found to be more than 99%, whereas I2 was measured to be less than 1%. When potassium iodide solution was used from low to high concentration (1000 ppm to 10000 ppm), the iodide rejection was found to be than more 90%. Since, CTA membrane is negatively charged and I- is anionic in nature, so it will from electrostatic repulsion and hence there will be higher rejection. The overall performance demonstrates that recovery of concentrated iodide using FO system is a promising technology.

Keywords: draw solution, EDTA-2Na, forward osmosis, potassium iodide

Procedia PDF Downloads 339

Authors: Djelloul Addad, Fatiha Belkhadem Mokhtari

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The objective of this work is to study the retention of methylene blue (MB) by biomass. The Biomass is characterized by X-ray diffraction (XRD), infrared absorption (IRTF). Results show that the biomass contains organic and mineral substances. The effect of certain physicochemical parameters on the adsorption of MB is studied (effect of the pH). This study shows that the increase in the initial concentration of MB leads to an increase in the adsorbed quantity. The adsorption efficiency of MB decreases with increasing biomass mass. The adsorption kinetics show that the adsorption is rapid, and the maximum amount is reached after 120 min of contact time. It is noted that the pH has no great influence on the adsorption. The isotherms are best modelled by the Langmuir model. The adsorption kinetics follow the pseudo-second-order model. The thermodynamic study of adsorption shows that the adsorption is spontaneous and exothermic.

Keywords: dyes, adsorption, biomass, methylene blue, langmuir

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Authors: M. Hoseinnezhad, K. Gharanjig

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Two organic dyes comprising carbazole as the electron donors and cyanoacetic acid moieties as the electron acceptors were synthesized. The organic dye was prepared by standard reaction from carbazole as the starting material. To this end, carbazole was reacted with bromobenzene and further oxidation and reacted with cyanoacetic acid. The obtained organic dye was purified and characterized using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (¹HNMR), carbon nuclear magnetic resonance (¹³CNMR) and elemental analysis. The influence of heteroatom on carbazole donors and cyno substitution on the acid acceptor is evidenced by spectral and electrochemical photovoltaic experiments. Finally, light fastness properties for organic dye were investigated.

Keywords: dye-sensitized solar cells, indoline dye, nanostructure, oxidation potential, solar energy

Procedia PDF Downloads 164

Authors: Dewi Selvia Fardhyanti, Astrilia Damayanti

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Coal tar is a liquid by-product of the process of coal gasification and carbonation, also in some industries such as steel, power plant, cement, and others. This liquid oil mixture contains various kinds of useful compounds such as aromatic compounds and phenolic compounds. These compounds are widely used as raw material for insecticides, dyes, medicines, perfumes, coloring matters, and many others. This research investigates thermodynamic modelling of liquid-liquid equilibria (LLE) in solvent extraction of o-Cresol from the coal tar. The equilibria are modeled by ternary components of Wohl, Van Laar, and Three-Suffix Margules models. The values of the parameters involved are obtained by curve-fitting to the experimental data. Based on the comparison between calculated and experimental data, it turns out that among the three models studied, the Three-Suffix Margules seems to be the best to predict the LLE of o-Cresol for those system.

Keywords: coal tar, o-Cresol, Wohl, Van Laar, three-suffix margules

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Authors: Pei Li, Chunyi Zhi

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Conversion-type lithium-ion batteries show great potential as high-energy-density, low-cost and sustainable alternatives to current transition-metal-based intercalation cells. Li-Cl₂/Li⁻I₂ conversion batteries, based on anionic redox reactions of Cl⁻/Cl⁰ or I⁻/I⁰, are highly attractive due to their superior voltage and capacity. However, a redox-active and reversible chlorine cathode has not been developed in organic electrolytes. And thermodynamic instability and shuttling issues of iodine cathodes have plagued the active iodine loading, capacity retention and cyclability. By reversible chemical bonds, we develop reversible chlorine redox reactions in organic electrolytes with interhalogen bonds between I and Cl for Li-I₂ batteries and develop a highly thermally stable I/I₃--bonded organic salts with iodine content up to 80% as cathode materials for the rechargeable Li-I₂ batteries. The demonstration of reversible chemical bonds enabled rechargeable Li-halogen batteries opens a new avenue to develop halogen compound cathodes.

Keywords: conversion-type, chlorine, halogen cathode, high energy density, iodine, interhalogen bond, lithium-ion batteries

Procedia PDF Downloads 48

Authors: Sylwia Krawiec, Joanna Cabaj, Karol Malecha

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Nowadays, progress in the field of the analytical methods is of great interest for reliable biological research and medical diagnostics. Classical techniques of chemical analysis, despite many advantages, do not permit to obtain immediate results or automatization of measurements. Chemical sensors have displaced the conventional analytical methods - sensors combine precision, sensitivity, fast response and the possibility of continuous-monitoring. Biosensor is a chemical sensor, which except of conventer also possess a biologically active material, which is the basis for the detection of specific chemicals in the sample. Each biosensor device mainly consists of two elements: a sensitive element, where is recognition of receptor-analyte, and a transducer element which receives the signal and converts it into a measurable signal. Through these two elements biosensors can be divided in two categories: due to the recognition element (e.g immunosensor) and due to the transducer (e.g optical sensor). Working of optical sensor is based on measurements of quantitative changes of parameters characterizing light radiation. The most often analyzed parameters include: amplitude (intensity), frequency or polarization. Changes in the optical properties one of the compound which reacts with biological material coated on the sensor is analyzed by a direct method, in an indirect method indicators are used, which changes the optical properties due to the transformation of the testing species. The most commonly used dyes in this method are: small molecules with an aromatic ring, like rhodamine, fluorescent proteins, for example green fluorescent protein (GFP), or nanoparticles such as quantum dots (QDs). Quantum dots have, in comparison with organic dyes, much better photoluminescent properties, better bioavailability and chemical inertness. These are semiconductor nanocrystals size of 2-10 nm. This very limited number of atoms and the ‘nano’-size gives QDs these highly fluorescent properties. Rapid and sensitive detection of dopamine is extremely important in modern medicine. Dopamine is very important neurotransmitter, which mainly occurs in the brain and central nervous system of mammals. Dopamine is responsible for the transmission information of moving through the nervous system and plays an important role in processes of learning or memory. Detection of dopamine is significant for diseases associated with the central nervous system such as Parkinson or schizophrenia. In developed optical biosensor for detection of dopamine, are used graphene quantum dots (GQDs). In such sensor dopamine molecules coats the GQD surface - in result occurs quenching of fluorescence due to Resonance Energy Transfer (FRET). Changes in fluorescence correspond to specific concentrations of the neurotransmitter in tested sample, so it is possible to accurately determine the concentration of dopamine in the sample.

Keywords: biosensor, dopamine, fluorescence, quantum dots

Procedia PDF Downloads 337

Authors: Han Longxiang

Abstract:

In the process of treating industrial oil wastewater with complex components, the traditional treatment methods (flotation, coagulation, microwave heating, etc.) often produce high operating costs, secondary pollution, and other problems. In order to solve these problems, the materials with high flux and stability applied to surfactant-stabilized emulsions separation have gained huge attention in the treatment of oily wastewater. Nevertheless, four stable oil-in-water emulsions can be formed due to different surfactants (surfactant-free, anionic surfactant, cationic surfactant, and non-ionic surfactant), and the previous advanced materials can only separate one or several of them, cannot effectively separate in one step. Herein, a facile synthesis method of graphene-based multilevel filter materials (GMFM) can efficiently separate the oil-in-water emulsions stabilized with different surfactants only through its gravity. The prepared materials with high stability of 20 cycles show a high flux of ~ 5000 L m-2 h-1 with a high separation efficiency of > 99.9 %. GMFM can effectively separate the emulsion stabilized by mixed surfactants and oily wastewater from factories. The results indicate that the GMFM has a wide range of applications in oil-in-water emulsions separation in industry and environmental science.

Keywords: emulsion, filtration, graphene, one-step

Procedia PDF Downloads 50

Authors: D. S. Fardhyanti, Megawati, W. B. Sediawan

Abstract:

Coal tar is a liquid by-product of the process of coal gasification and carbonation. This liquid oil mixture contains various kinds of useful compounds such as aromatic compounds and phenolic compounds. These compounds are widely used as raw material for insecticides, dyes, medicines, perfumes, coloring matters, and many others. This research investigates thermodynamic modelling of liquid-liquid equilibria (LLE) in the separation of phenol from the coal tar by solvent extraction. The equilibria are modeled by ternary components of Wohl, Van Laar, and Three-Suffix Margules models. The values of the parameters involved are obtained by curve-fitting to the experimental data. Based on the comparison between calculated and experimental data, it turns out that among the three models studied, the Three-Suffix Margules seems to be the best to predict the LLE of p-Cresol mixtures for those system.

Keywords: coal tar, phenol, Wohl, Van Laar, Three-Suffix Margules

Procedia PDF Downloads 228

Authors: Han Longxiang

Abstract:

In the process of treating industrial oily wastewater with complex components, the traditional treatment methods (flotation, coagulation, microwave heating, etc.) often produce high operating costs, secondary pollution, and other problems. In order to solve these problems, the materials with high flux and stability applied to surfactant-stabilized emulsions separation have gained huge attention in the treatment of oily wastewater. Nevertheless, four stable oil-in-water emulsions can be formed due to different surfactants (surfactant-free, anionic surfactant, cationic surfactant, and non-ionic surfactant), and the previous advanced materials can only separate one or several of them, cannot effectively separate in one step. Herein, a facile synthesis method of graphene-based multilevel filter materials (GMFM) which can efficiently separate the oil-in-water emulsions stabilized with different surfactants only through its gravity. The prepared materials with high stability of 20 cycles show a high flux of ~ 5000 L m-2 h-1 with a high separation efficiency of > 99.9 %. GMFM can effectively separate the emulsion stabilized by mixed surfactants and oily wastewater from factories. The results indicate that the GMFM have a wide range of applications in oil-in-water emulsions separation in industry and environmental science.

Keywords: emulsion, filtration, graphene, one-step

Procedia PDF Downloads 61

Authors: Hwei Voon Lee, N. Asikin-Mijana, Y. H. Taufiq-Yap, J. C. Juan, N. A. Rahman

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Cracking–Deoxygenation process is one of the important reaction pathways for the production of bio-fuel with desirable n-C17 hydrocarbon chain via removal of oxygen compounds. Calcium-based catalyst has attracted much attention in deoxygenation process due to its relatively high capacity in removing oxygenated compounds in the form of CO₂ and CO under decarboxylation and decarbonylation reaction, respectively. In the present study, deoxygenation of triolein was investigated using Ca(OH)₂ nanocatalyst derived from low cost natural waste shells. The Ca(OH)₂ nanocatalyst was prepared via integration techniques between surfactant treatment (anionic and non-ionic) and wet sonochemical effect. Results showed that sonochemically assisted surfactant treatment has successfully enhanced the physicochemical properties of Ca(OH)₂ nanocatalyst in terms of nanoparticle sizes (∼50 nm), high surface area(∼130 m²g⁻¹), large porosity (∼18.6 nm) and strong basic strength. The presence of superior properties from surfactant treated Ca(OH)₂ nanocatalysts rendered high deoxygenation degree, which is capable of producing high alkane and alkene selectivity in chain length of n-C17(high value of C17/(n-C17+ n-C18)ratio = 0.88). Furthermore, both Ca(OH)₂–EG and Ca(OH)₂–CTAB nanocatalysts showed high reactivity with 47.37% and 44.50%, respectively in total liquid hydrocarbon content of triolein conversion with high H/C and low O/C ratio.

Keywords: clamshell, cracking, decarboxylation-decarbonylation, hydrocarbon

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Authors: G. Swati, D. Haranath

Abstract:

Commercially available long afterglow /persistent phosphors are proprietary materials and hence the exact composition and phase responsible for their luminescent characteristics such as initial intensity and afterglow luminescence time are not known. Further to generate various emission colors, commercially available persistence phosphors are physically blended with fluorescent organic dyes such as rodhamine, kiton and methylene blue etc. Blending phosphors with organic dyes results into complete color coverage in visible spectra, however with time, such phosphors undergo thermal and photo-bleaching. This results in the loss of their true emission color. Hence, the current work is dedicated studies on inorganic based thermally and chemically stable primary color emitting nanophosphors namely SrAl2O4:Eu2+, Dy3+, (CaZn)TiO3:Pr3+, and Sr2MgSi2O7:Eu2+, Dy3+. SrAl2O4: Eu2+, Dy3+ phosphor exhibits a strong excitation in UV and visible region (280-470 nm) with a broad emission peak centered at 514 nm is the characteristic emission of parity allowed 4f65d1→4f7 transitions of Eu2+ (8S7/2→2D5/2). Sunlight excitable Sr2MgSi2O7:Eu2+,Dy3+ nanophosphors emits blue color (464 nm) with Commercial international de I’Eclairage (CIE) coordinates to be (0.15, 0.13) with a color purity of 74 % with afterglow time of > 5 hours for dark adapted human eyes. (CaZn)TiO3:Pr3+ phosphor system possess high color purity (98%) which emits intense, stable and narrow red emission at 612 nm due intra 4f transitions (1D2 → 3H4) with afterglow time of 0.5 hour. Unusual property of persistence luminescence of these nanophoshphors supersedes background effects without losing sensitive information these nanophosphors offer several advantages of visible light excitation, negligible substrate interference, high contrast bifurcation of ridge pattern, non-toxic nature revealing finger ridge details of the fingerprints. Both level 1 and level 2 features from a fingerprint can be studied which are useful for used classification, indexing, comparison and personal identification. facile methodology to extract high contrast fingerprints on non-porous and porous substrates using a chemically inert, visible light excitable, and nanosized phosphorescent label in the dark has been presented. The chemistry of non-covalent physisorption interaction between the long afterglow phosphor powder and sweat residue in fingerprints has been discussed in detail. Real-time fingerprint development on porous and non-porous substrates has also been performed. To conclude, apart from conventional dark vision applications, as prepared primary color emitting afterglow phosphors are potentional candidate for developing high contrast latent fingerprints.

Keywords: fingerprints, luminescence, persistent phosphors, rare earth

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Authors: Y. Kobayashi, T. Kurosaka, K. Yamamura, T. Yonezawa, K. Yamasaki

Abstract:

The present work reports an effect of surface- modification of indium tin oxide (ITO) particles with chemicals on their electronic conductivity properties. Examined chemicals were polyvinyl alcohol (nonionic polymer), poly(diallyl dimethyl ammonium chloride) (cationic polymer), poly(sodium 4-styrene-sulfonate) (anionic polymer), (2-aminopropyl) trimethoxy silane (APMS) (silane coupling agent with amino group), and (3-mercaptopropyl) trimethoxy silane (MPS) (silane coupling agent with thiol group). For all the examined chemicals, volume resistivities of surface-modified ITO particles did not increase much when they were aged in air at 80 ^oC, compared to a volume resistivity of un-surface-modified ITO particles. Increases in volume resistivities of ITO particles surface-modified with the silane coupling agents were smaller than those with the polymers, since hydrolysis of the silane coupling agents and condensation of generated silanol and OH groups on ITO particles took place to provide efficient immobilization of them on particles. The APMS gave an increase in volume resistivity smaller than the MPS, since a larger solubility in water of APMS providing a larger amount of APMS immobilized on particles.

Keywords: indium tin oxide, particles, surface-modification, volume resistivity

Procedia PDF Downloads 233

Authors: Andreas Aceranti, Simonetta Vernocchi, Marco Colorato, Ludwig Conistabile, Martina Falappi

Abstract:

This study was born out of the necessity to delve into and understand the intricate world of tattoos, a millenary art that lays its foundation, although sometimes complex, for effective non-verbal communication. What is most astonishing about a phenomenon such as irreversibly branding the skin, which at first glance may appear superficial, especially in the eyes of those who do not fully understand its meaning, is the fact that it is actually one of the most enduring forms of communication: body modification through tattoos or ornamental dyes indicated the wearer's membership in a particular ethnic group, social class or religious community. Even within crime-based aggregations, tattoos had (and still have) the purpose of conveying one's affiliation to a particular group, thus making one's criminal identity known. The profession of a language and cultural mediator teaches that it is essential to be able to read between the lines to grasp all those aspects that words alone do not convey. Tattooing, therefore, becomes a tool of analysis and a language that is not secondary to be taken into account for an in-depth reading of the reality that surrounds us and of cultures different from our own.

Keywords: tattoo, cultural tattoos, tattooing, non verbal communication

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Authors: Poojan Gharat, Haridas Pal, Sharmistha Dutta Choudhury

Abstract:

Tuning photophysical properties of guest dyes through host-guest interactions involving macrocyclic hosts are the attractive research areas since past few decades, as these changes can directly be implemented in chemical sensing, molecular recognition, fluorescence imaging and dye laser applications. Excited state intramolecular proton transfer (ESIPT) is an intramolecular prototautomerization process display by some specific dyes. The process is quite amenable to tunability by the presence of different macrocyclic hosts. The present study explores the interesting effect of p-sulfonatocalix[n]arene (SCXn) and cyclodextrin (CD) hosts on the excited-state prototautomeric equilibrium of Chrysazine (CZ), a model antitumour drug. CZ exists exclusively in its normal form (N) in the ground state. However, in the excited state, the excited N* form undergoes ESIPT along with its pre-existing intramolecular hydrogen bonds, giving the excited state prototautomer (T*). Accordingly, CZ shows a single absorption band due to N form, but two emission bands due to N* and T* forms. Facile prototautomerization of CZ is considerably inhibited when the dye gets bound to SCXn hosts. However, in spite of lower binding affinity, the inhibition is more profound with SCX6 host as compared to SCX4 host. For CD-CZ system, while prototautomerization process is hindered by the presence of β-CD, it remains unaffected in the presence of γCD. Reduction in the prototautomerization process of CZ by SCXn and βCD hosts is unusual, because T* form is less dipolar in nature than the N*, hence binding of CZ within relatively hydrophobic hosts cavities should have enhanced the prototautomerization process. At the same time, considering the similar chemical nature of two CD hosts, their effect on prototautomerization process of CZ would have also been similar. The atypical effects on the prototautomerization process of CZ by the studied hosts are suggested to arise due to the partial inclusion or external binding of CZ with the hosts. As a result, there is a strong possibility of intermolecular H-bonding interaction between CZ dye and the functional groups present at the portals of SCXn and βCD hosts. Formation of these intermolecular H-bonds effectively causes the pre-existing intramolecular H-bonding network within CZ molecule to become weak, and this consequently reduces the prototautomerization process for the dye. Our results suggest that rather than the binding affinity between the dye and host, it is the orientation of CZ in the case of SCXn-CZ complexes and the binding stoichiometry in the case of CD-CZ complexes that play the predominant role in influencing the prototautomeric equilibrium of the dye CZ. In the case of SCXn-CZ complexes, the results obtained through experimental findings are well supported by quantum chemical calculations. Similarly for CD-CZ systems, binding stoichiometries obtained through geometry optimization studies on the complexes between CZ and CD hosts correlate nicely with the experimental results. Formation of βCD-CZ complexes with 1:1 stoichiometry while formation of γCD-CZ complexes with 1:1, 1:2 and 2:2 stoichiometries are revealed from geometry optimization studies and these results are in good accordance with the observed effects by the βCD and γCD hosts on the ESIPT process of CZ dye.

Keywords: intermolecular proton transfer, macrocyclic hosts, quantum chemical studies, photophysical studies

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Authors: P. Gomathi Priya, M. E. Thenmozhi

Abstract:

Iron nanoparticles were used to cleanup effluents. This paper involves synthesis of iron nanoparticles chemically by sodium borohydride reduction of ammonium ferrous sulfate solution (FAS). Iron oxide nanoparticles have lesser efficiency of adsorption than Zero Valent Iron nanoparticles (nZVI). Glucosamine acts as a stabilizing agent and chelating agent to prevent Iron nanoparticles from oxidation. nZVI particles were characterized using Scanning Electron Microscopy (SEM). Thus, the synthesized nZVI was subjected to entrapment in biopolymer, viz. barium (Ba)-alginate beads. The beads were characterized using SEM. Batch dye degradation studies were conducted using Reactive black Water soluble Nontoxic Natural substances (WNN) dye which is one of the most hazardous dyes used in textile industries. Effect of contact time, effect of pH, initial dye concentration, adsorbent dosage, isotherm and kinetic studies were carried out.

Keywords: ammonium ferrous sulfate solution, barium, alginate beads, reactive black WNN dye, zero valent iron nanoparticles

Procedia PDF Downloads 299

Authors: S. Tartaya, R. Bagtache, A. M. Djaballah, M. Trari

Abstract:

Due to the increase in the trade of colored products and their applications in various fields such as cosmetic, food, textile, pharmaceutical industries, etc. Dyes constitute a large part of the contaminants in wastewater and cause serious damage in the environment and the aquatic system. Photocatalytic systems are highly efficient processes for treating wastewater in the presence of semiconductor photocatalysts. In this field, we report our contribution by synthesizing a potassium vanadium fluorophosphate compound KVPO4F (which is abbreviated KVPOF) by a simplified hydrothermal method at 180°C for 5 days. The as synthesized product has been characterized physically and photoelectrochemically. The indirect optical transition of 1.88 eV, determined from the diffuse reflectance, was assigned to the charge transfer. Moreover, the curve (C-2–E) of the KVPOF displayed n-type character of the semiconductor. Even more, interestingly, the photocatalytic performance was evaluated through the photo-degradation of cationic dye Methyl Violet (MV). An abatement of 61% was obtained after 6 h of irradiation under visible light.

Keywords: KVPO4F, photocatalysis, semiconductor, wastewater, environment

Procedia PDF Downloads 46