Yet shells harbour useful chemicals - protein, calcium carbonate and chitin, a polymer similar to cellulose, but which contains nitrogen (see 'Shell biorefinery'). The potential value of such shells ...for the chemical industry is being ignored. Scientists should work out sustainable ways to refine crustacean shells, and governments and industry should invest in using this abundant and cheap renewable resource.
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DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
Biogenic synthesis of nanoparticles: A review Sharma, Deepali; Kanchi, Suvardhan; Bisetty, Krishna
Arabian journal of chemistry,
December 2019, 2019-12-00, 2019-12-01, Volume:
12, Issue:
8
Journal Article
Peer reviewed
Open access
The nature acts like a large “bio-laboratory” comprising of plants, algae, fungi, yeast, etc. which are composed of biomolecules. These naturally occurring biomolecules have been identified to play ...an active role in the formation of nanoparticles with distinct shapes and sizes thereby acting as a driving force for the designing of greener, safe and environmentally benign protocols for the synthesis of nanoparticles. The present review targets the comparative biogenic synthesis and mechanisms of nanoparticles using algae and waste materials (agro waste in the presence of biomolecules). The use of waste materials not only reduces the cost of synthesis but also minimizes the need of using hazardous chemicals and stimulates ‘green synthesis’. It also focuses on the computational aspects of binding of biomolecules to nanoparticles and some of the applications of the biosynthesized nanoparticles in biomedical, catalysis and biosensors fields.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Anticipating the next century of wastewater treatment van Loosdrecht, Mark C. M.; Brdjanovic, Damir
Science (American Association for the Advancement of Science),
06/2014, Volume:
344, Issue:
6191
Journal Article
Peer reviewed
Advances in activated sludge sewage treatment can improve its energy use and resource recovery
Rapid urbanization and industrialization in the 19th century led to unhealthy environments and ...wide-spread epidemic diseases. In response, research was undertaken that led to the development of sanitation technology. Exactly 100 years since the activated sludge process was presented (
1
), it is still at the heart of current sewage treatment technology. Activated sludge is a mixture of inert solids from sewage combined with a microbial population growing on the biodegradable substrates present in the sewage. The settling and recycling of sludge inside treatment plants was the invention of Ardern and Lockett. The current demands from a rapidly growing human population and the need for a more sustainable society are pushing forward new developments for sewage handling. These developments have two main drivers: general process improvements and the contribution to the recycling of resources (
2
,
3
).
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
High performance carbonized bamboo fibers were synthesized for a wide range of temperature dependent energy storage applications. The structural and electrochemical properties of the carbonized ...bamboo fibers were studied for flexible supercapacitor applications. The galvanostatic charge-discharge studies on carbonized fibers exhibited specific capacity of ~510F/g at 0.4 A/g with energy density of 54 Wh/kg. Interestingly, the carbonized bamboo fibers displayed excellent charge storage stability without any appreciable degradation in charge storage capacity over 5,000 charge-discharge cycles. The symmetrical supercapacitor device fabricated using these carbonized bamboo fibers exhibited an areal capacitance of ~1.55 F/cm(2) at room temperature. In addition to high charge storage capacity and cyclic stability, the device showed excellent flexibility without any degradation to charge storage capacity on bending the electrode. The performance of the supercapacitor device exhibited ~65% improvement at 70 °C compare to that at 10 °C. Our studies suggest that carbonized bamboo fibers are promising candidates for stable, high performance and flexible supercapacitor devices.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
This review is an attempt to assess the adsorption performance of different green adsorbents derived from agricultural waste materials (AWMs) that were used for the elimination of bisphenol A (BPA) ...from aqueous matrices. Different processes including grafting, polymerization, activation and chemical treatment have been applied to functionalize and modify agricultural waste materials for the purposes of increasing their adsorptive performances toward BPA. The highest reported adsorption capacity of adsorbent from agricultural waste for the uptake of BPA is the highly microporous carbon adsorbent derived from Argan nut shell (1408 mg g−1). Hydrogen bonding, hydrophobic and π-π interactions were reported in most studies as the main mechanisms governing the adsorption of BPA onto agricultural waste adsorbents. Equilibrium isotherm and kinetic studies for the uptake of BPA onto agricultural waste adsorbents were best described by Langmuir/Freundlich model and pseudo-second order model, respectively. Despite the effective elimination of BPA by various agricultural waste adsorbents, an appropriate selection of elution solvent is important for effective desorption of BPA from spent adsorbent. To date, ethanol, diethyl ether-methanol, methanol-acetic acid, mineral acids and sodium hydroxide are the most eluents applied for desorption of BPA molecules loaded onto AW-adsorbents. Looking toward the future, studies on the agricultural waste adsorbents based on polymers, activated carbons, nanoparticles and highly microporous carbons should be mostly considered by the researchers toward removing BPA. These future studies should be performed both in laboratory, pilot and industrial scales, and also should report the sustainable techniques for disposal of the spent AW-adsorbents after lose their adsorption performance on BPA.
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•Agricultural waste adsorbents are very effective for removal of BPA.•Argan nut shell derived microporous carbon had highest qe (1408 mg g−1) for BPA.•Langmuir/Freundlich and pseudo-second order models are best to fit the results.•H-bonding, hydrophobic and π-π interactions are main mechanisms for BPA removal.•Future prospects of agricultural waste adsorbents for BPA removal were discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•A comprehensive review of geopolymer concrete.•Constituents of geopolymer concrete in detail.•Characterization of geopolymer concrete.•Properties of geopolymer ...concrete.•Environmental impact of geopolymer concrete.
The rise in population and improvement in the lifestyle of human beings has caused a rapid increase in energy demands for buildings in the present day. An upsurge in energy demand, lack of fossil fuels, and environmental issues provide a crucial motive to the development of sustainable and viable infrastructure. Geopolymer (GP) composite free from cement, made from various waste materials with a high amount of Al2SiO3 and Na2SiO3/NaOH (alkali-activated silica) is evolving as an eminent material for sustainability purposes. They are also preferred due to the lesser emission of greenhouse gases as compared to ordinary Portland cement (OPC). This paper aims at presenting a sustainable domain and state of the art review of GP composite. The properties of composites made from various geopolymeric waste binders are presented. Besides, the microstructure and chemical characterization of GP composites are also discussed. The durability of GP composite is also highlighted considering its deterioration in various aggressive environments. In the end, a global warming potential (GWP) assessment was conducted and the practical applications of GP composites in the building industry are also provided.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this study, we prepared a range of nanoporous carbon nano-adsorbents from crab shells (CSs) using KOH activation and evaluated their suitability for selective adsorption of CO2/CH4 gas mixtures. ...We employed various characterization techniques, including XRD, FT-IR, SEM, Raman, TGA, and BET analysis, to assess the properties of these nano-adsorbents. Our investigation includes the systematic study of various parameters, such as activation time, activation temperature, and the KOH to CS activating agent ratio. The nanoporous carbons were evaluated for their CO2 adsorption capabilities at 1–10 bar and 25 ℃ condition. The results demonstrated that the CS-2-2-900 sample, activated for 1 h at 900 ℃ with a 2:1 ratio of KOH to CS, exhibited the highest gas adsorption capacity, reaching 7.217 mmol/g at a pressure of 10 bar under room temperature conditions. Additionally, the synthesized CS-2-2-900 sample displayed excellent surface area (914.85 m2/g), a pore volume of 1.1 cm3/g, and an average pore diameter of 4.82 nm. Furthermore, we functionalized the CSs to enhance their selectivity for ammonia adsorption. Using the Myers and Pravnitz theory, we calculated that the FCS-2-2-900 sample exhibited the highest selectivity, reaching 18.99 at 25 ℃ under pressures of up to 10 bar. To gain a more comprehensive understanding of the interactions between the adsorbents and the adsorbed molecules, as well as to identify the active sites involved in the adsorption process, we employed density functional theory (DFT). Our DFT calculations revealed that pyrrolic nitrogen and carboxylic sites played a significant role in enhancing the separation of CO2 in binary mixtures. In summary, nanoporous carbons derived from crab shells outperformed those derived from other waste materials. These functionalized porous nanocarbons represent promising adsorbents for the selective adsorption of CO2 gas in CO2/CH4 mixtures due to their nitrogen content, high porosity, stability, and economic efficiency.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
In this contribution, authors present a review on the state-of-the-art in the utilization of industrial and agricultural waste materials for the development of metal–matrix composites (MMCs), ...providing, through the judicious analysis of an ample and varied references source – from the oldest to the newest ones – an insight into the challenges and opportunities for the exploitation to their full potential. In addition to its topicality, the novelty of this contribution lies in the presentation of key statistical, technical, and property-related information of a comprehensive variety of waste materials classed into two main groups, namely, fly ash reinforced MMCs and MMCs derived from other waste materials. Although fly ash has been exploited in a broad range of applications, the attention paid for its use in the development of MMCs seems to be insufficient. A purposely designed chart helped to pinpoint the more demanding and profitable applications of fly ash, and establish strategic opportunity areas. With the exception of the recent utilization of fly ash for the automotive industry, virtually no other waste material has been reused for a specific industrial application. In this context, by identifying five reasons for this observed delay, an essential goal of this review is to arouse the interest of academicians, scientists/technologists, and industrialists in the use of those materials for the fabrication of MMCs. In the case of agricultural materials, a twofold perspective may apply, because while on the one hand, certain chemical elements have to be removed for specific applications, on the other hand, recovery of certain elements might be more attractive. Based on the significant progress observed so far, in terms of scientific and technological research, a promising future can be anticipated. The proper use of industrial and agricultural waste materials entails knowledge generation as a prerequisite for incubation of pilot-plant and industrialization stages, culminating with all related benefits to society.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
Vicinal dibromides and dichlorides are important commodity chemicals and indispensable synthetic intermediates in modern chemistry that are traditionally synthesized using hazardous elemental ...chlorine and bromine. Meanwhile, the environmental persistence of halogenated pollutants necessitates improved approaches to accelerate their remediation. Here, we introduce an electrochemically assisted shuttle (
shuttle) paradigm for the facile and scalable interconversion of alkenes and vicinal dihalides, a class of reactions that can be used both to synthesize useful dihalogenated molecules from simple alkenes and to recycle waste material through
-dihalogenation. The reaction is demonstrated using 1,2-dibromoethane, as well as 1,1,1,2-tetrachloroethane or 1,2-dichloroethane, to dibrominate or dichlorinate, respectively, a wide range of alkenes in a simple setup with inexpensive graphite electrodes. Conversely, the hexachlorinated persistent pollutant lindane could be fully dechlorinated to benzene in soil samples using simple alkene acceptors.
Growing environmental concerns associated with the accumulation of plastic waste in the natural environment has incentivised considerable research into renewable alternatives, and more recently, ...alternative waste management strategies. This review aims to introduce poly (lactic acid) (PLA), a bioplastic, and recent research within the field. Attention will then shift to research surrounding plastic waste management. Various end-of-life (EOL) options available to plastics will be discussed more broadly, before presenting existing technologies, challenges and future opportunities exclusively for PLA. Herein, all waste management strategies presented for PLA are discussed within the context of industrial feasibility.
•The current and future prospects of bioplastics is discussed with emphasis on poly (lactic acid) (PLA).•The production of lactic acid and subsequent routes and mechanisms to PLA are presented with key PLA properties are outlined.•The end-of life options for plastics are discussed in the context of a circular economy.•Waste management strategies for PLA are discussed in greater detail with emphasis on chemical recycling techinqiues.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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