56 research outputs found

    Application of Titanium Dioxide in the Synthesis of Mesoporous Activated Carbon Derived from Agricultural Waste

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    Adsorption is an important technique that significances the characteristics of porous solid materials and fine powders. The importance of porous solid materials and fine powders has been recognized when porous coal used for various applications such as catalysis, separation, isolation, sensors, chromatography, etc. Herein, the synthesis of mesoporous activated carbon derived from agricultural waste using TiO2. The TiO2-modified carbon was characterized employing scanning electron microscope (SEM), attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, powder X-ray diffraction (pXRD), Brunauer–Emmett–Teller (BET) surface area analyzer and X-ray photoelectron spectroscopy (XPS). The obtained results suggested that the TiO2-modified carbon could be a potential material for various application like dye removal, metal removal and allied areas. This book chapter describes the commonly used classifications of porous bulk materials and also reported here the characterization of porous solid materials and fine powders with special reference to the evaluation of the surface area, pore size distribution and thermodynamic parameters of the different mesoporous material, at various scales of resolution using relevant techniques. These materials comprise several levels of structures that of the mesopores, micropores as well as macropores. The apparent topography analysis of these materials, of various pore diameters, synthesized in our laboratory has been determined at various scales with the help of various characterization techniques

    Application of Cellulose Derivatives in Mineral Processing

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    Cellulose derivatives (CDs) have been recognized as an anionic water-soluble, non-toxic, biocompatible and biodegradable polysaccharide. The CDs have been used as a viscosity regulator, thickening agent, sizing agent and coating agent and emulsion stabilizer, electrode binder in various industries. These characteristics properties of CDs are associated with hydroxyl groups/functionalized groups present in their structure. The CDs have significant advantages in various fields including several industrial applications such as mineral processing, palletisation process, oil drilling industrial applications due to their non-toxic and selective properties. Moreover, The CDs have been extensively used as a depressant, dispersant as well as flocculants in mineral processing from various ores. During the mineral processing like flotation of sulfide minerals highly toxic inorganic species were used as dispersant and depressant which ultimately cases environmental toxicity. Therefore, there is a current need to introduce CDs as various alternative nontoxic dispersant and flocculants. This chapter emphasized an overview of the application of CDs in mineral processing including the structure, properties of the commonly used minerals processing

    Removal of Arsenic - “A Silent Killer” in the Environment by Adsorption Methods

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    Water is one of the most essential requirements for living being to survive because 70–80% of the mass of most living bodies consists of water and various mineral and organic salts. Water is also most important component of our environment. Large amount of water is used in various industries or commercial level or domestic level and finally effluent water is loaded with large amount of pollutants such as organic chemicals (surfactants, dyes, phenols etc.), inorganic hazardous heavy metals (As in present case) microbes (bacteria, fungi etc.) pollutants particulate etc. Arsenic is a natural metalloid chemical that may be present in groundwater and surface water gets polluted, hence, aquatic life of plants and animals is disturbed and cause abnormal growth and various diseases, hence, short term or long term changes occurs in ecosystem. Hence, treatment of wastewater is essentially required before discharge effluent wastewater into ponds or lagoons, drains and rivers. Arsenic is one such element that contaminates the environment as reported in several countries. The largest population at risk is in Bangladesh followed by India (West Bengal). Arsenic is familiar as silent killer because dissolved in water, it is colorless, odorless, and tasteless, yet consumption of relatively small doses of this element in its most toxic forms can cause rapid and violent death. It is a human carcinogen in water over a wide range of pH values, having harmful effects on both human health and environment, even at low concentration. Because of this effect, the World Health Organization (WHO) and the US Environmental Protection Agency (USEPA) set the arsenic standard for drinking water at .010 ppm to protect consumers served by public water systems. Ingestion only poses health problems if a dangerous amount of arsenic enters the body. Then, it can lead to cancer, liver disease, coma, and death. There is no effective treatment for arsenic toxicity. Only the removal of arsenic from aqueous system can prevent the toxicity. A great deal of research over recent decades has been done to lower the concentration of arsenic in drinking water and still there is a need to develop ecofriendly techniques. Existing major arsenic removal technologies include oxidation, adsorption, precipitation, coagulation and membrane separation. This book chapter presents a systematic description of current status of research in the area of arsenic removal from contaminated water and comparison of all technologies available with more emphasis on adsorption

    Structure and Properties of Dyes and Pigments

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    Colour is one of the elements of nature that makes human life more aesthetic and fascinating in the world. Plants, animals, and minerals have been used as primary sources for colourants, dyes or pigments since ancient times. In our daily life, we know about many substances which have specific colours. These are the substances which are used as colourants i.e.; colour imparting species. Both dyes and pigments are coloured as they absorb only some wavelength of visible light. Their structures have Aryl rings that have delocalized electron systems. These structures are said to be responsible for the absorption of electromagnetic radiation that has varying wavelengths, based upon the energy of the electron clouds. Dyes are coloured organic compounds that are used to impart colour to various substrates, including paper, leather, fur, hair, drugs, cosmetics, waxes, greases, plastics and textile materials. A Dye is a coloured compound due to the presence of chromophore and its fixed property to the acid or basic groups such as OH, SO3H, NH2, NR2, etc. The polar auxochrome makes the dye water-soluble and binds the dye to the fabric by interaction with the oppositely charged groups of the fabric structure. Pigments are organic and inorganic compounds which are practically insoluble in medium in which they are incorporated. Dyes and pigments are the most important colourants used to add colour or to change the colour of something. They are widely used in the textile, pharmaceutical, food, cosmetics, plastics, paint, ink, photographic and paper industries. This chapter is devoted to the structure and properties of dyes and pigments

    Gallbladder reporting and data system (GB-RADS) for risk stratification of gallbladder wall thickening on ultrasonography:an international expert consensus

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    The Gallbladder Reporting and Data System (GB-RADS) ultrasound (US) risk stratification is proposed to improve consistency in US interpretations, reporting, and assessment of risk of malignancy in gallbladder wall thickening in non-acute setting. It was developed based on a systematic review of the literature and the consensus of an international multidisciplinary committee comprising expert radiologists, gastroenterologists, gastrointestinal surgeons, surgical oncologists, medical oncologists, and pathologists using modified Delphi method. For risk stratification, the GB-RADS system recommends six categories (GB-RADS 0–5) of gallbladder wall thickening with gradually increasing risk of malignancy. GB-RADS is based on gallbladder wall features on US including symmetry and extent (focal vs. circumferential) of involvement, layered appearance, intramural features (including intramural cysts and echogenic foci), and interface with the liver. GB-RADS represents the first collaborative effort at risk stratifying the gallbladder wall thickening. This concept is in line with the other US-based risk stratification systems which have been shown to increase the accuracy of detection of malignant lesions and improve management. Graphical abstract: [Figure not available: see fulltext.]

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Influence of humic acid on ionisation constants of sulphurous acid: Calcium sulphite precipitation during clarification of cane juice

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    150-153The presence of humic acid seems to decrease the rate of CaSO3 precipitation during clarification of cane juice in the sugar manufacturing. The first and second ionisation constants of H2SO3 were found to decrease by 8 and 13% at RT in presence of humic acid in solution, respectively. However, t h e first and second ionisation constants of the acid were affected in the range 19-16% respectively across the temperature range 50-90°C. In the presence of humic acid the activation energy was found to increase. The nature of positive slope of Arrhenius plot indicates the diffusion controlled reaction in the precipitation reaction which is consistent with low value of activation energy of ionisation of sulphurous acid

    <span style="font-size:15.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI;mso-bidi-font-weight:bold" lang="EN-GB">Adsorption behaviours of phenols onto high specific area activated carbon derived from <i style="mso-bidi-font-style:normal">Trapa bispinosa</i> </span>

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    11-19A low cost activated carbon derived from an aquatic plant Trapa bispinosa (TB) residue, has been characterized for the removal of phenol and its derivatives (p-chlorophenol and p-nitrophenol) from their aqueous solutions. The derived Trapa bispinosa husk (TBH) has micro porous and meso porous pore size distribution with high surface area (454 m2 g-1) and high carbon content (77%). The Langmuir, Freundlich, Redlich-Peterson and Temkin models have been applied to evaluate the adsorption parameters. The possible adsorption interactions have been discussed. The effects of pH, urea and ionic strength on the adsorption suggest that the adsorption of phenols is attributed to hydrogen bonding; however, hydrophobic interactions and charge transfer interactions are also believed to be responsible for the observed adsorption in the present case. The adsorption decreases in the order of p-chlorophenol > phenol > p-nitrophenol. Thermodynamic study demonstrates an endothermic nature of adsorption. Adsorption kinetics is examined using different kinetics model (Lagergren first order and pseudo second order). The best results have been achieved with the Langmuir isotherm equilibrium model and followed pseudo second order kinetics (R2 = 0.99). The TBH is found to be very effective for removal of phenols from their aqueous solutions

    Adsorption behaviours of phenols onto high specific area activated carbon derived from Trapa bispinosa

    No full text
    A low cost activated carbon derived from an aquatic plant Trapa bispinosa (TB) residue, has been characterized for the removal of phenol and its derivatives (p-chlorophenol and p-nitrophenol) from their aqueous solutions. The derived Trapa bispinosa husk (TBH) has micro porous and meso porous pore size distribution with high surface area (454 m2 g-1) and high carbon content (77%). The Langmuir, Freundlich, Redlich-Peterson and Temkin models have been applied to evaluate the adsorption parameters. The possible adsorption interactions have been discussed. The effects of pH, urea and ionic strength on the adsorption suggest that the adsorption of phenols is attributed to hydrogen bonding; however, hydrophobic interactions and charge transfer interactions are also believed to be responsible for the observed adsorption in the present case. The adsorption decreases in the order of p-chlorophenol &gt; phenol &gt; p-nitrophenol. Thermodynamic study demonstrates an endothermic nature of adsorption. Adsorption kinetics is examined using different kinetics model (Lagergren first order and pseudo second order). The best results have been achieved with the Langmuir isotherm equilibrium model and followed pseudo second order kinetics (R2 = 0.99). The TBH is found to be very effective for removal of phenols from their aqueous solutions
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