| 1. |
- Anandhakumari, Govindharaj, et al.
(författare)
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Synthesis of strontium oxide-zinc oxide nanocomposites by Co-precipitation method and its application for degradation of malachite green dye under direct sunlight
- 2023
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Ingår i: Heliyon. - : Elsevier BV. - 2405-8440. ; 9:10
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Tidskriftsartikel (refereegranskat)abstract
- Photocatalysts workable under direct sunlight are the safe and cost-effective option for water purification. The nanocomposites of strontium oxide and zinc oxide (SZ NCs) were synthesized using coprecipitation method. The respective precursors of SZ NCs were subjected to alkaline hydrolysis and subsequently thermally treated to yield SZ NCs. The SZ NCs with different ZnO composition was synthesized by varying the concentration of ZnO precursor from 0.2 to 1 M. The structural properties of SZ NCs evaluated using X-Ray diffraction (XRD), Thermogravimetric analysis (TGA), and Differential thermal analysis DTA). The optical properties of SZ NCs studied using ultraviolet–visible (UV–Vis) spectroscopic study. The trend observed in the intensity of XRD peaks indicated the occurrence of Zn doping in the crystalline lattice of SrO and the formation of SrO–ZnO composite. Upon incorporation of 1 M of ZnO precursor, the grain size of the SrO was decreased from 49.3 to 27.6 nm. The weight loss in the thermal analysis indicates the removal of carbonates from the sample upon heating and shows the formation of an oxide structure. UV–Vis spectra confirmed that the presence of SrO enhanced the sunlight absorption of SZ NCs. The increase in the composition of ZnO precursors increased the bandgap of SrO (2.09 eV) to the level of ZnO (3.14 eV). SZ NCs exhibited heterostructure morphology, where the nanosized domains with varying shapes (layered and rod-like) were observed. Under direct sunlight conditions, SZ NCs prepared using 1 M/0.6 M of SrO/ZnO precursors exhibited 15–20 % higher photocatalytic efficiency than neat SrO and ZnO. In precise, 1 mg of this SZ NC was degraded 98 % of malachite green dye dissolved in water (10 ppm) under direct sunlight. Additionally, the thermal stability results showed that 18 % decomposition was obtained due to the degradation impurities in SrO/ZnO catalysts and the XRD results revealed that no structural change is obtained in SrO/ZnO photocatalysts after stability test. The SZ NCs can be effectively used as safe and economic sunlight photocatalysts for water purification in remote areas without the electricity.
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| 2. |
- Chudasama, Nishith A., et al.
(författare)
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Preparation of seaweed polysaccharide based hydrophobic composite membranes for the separation of oil/water emulsion and protein
- 2022
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Ingår i: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 199, s. 36-41
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Tidskriftsartikel (refereegranskat)abstract
- Agarose is a seaweed-based polysaccharide and is widely used for the separation of nucleic acids in molecular biology. Cross-linked agarose beads are also used as solid-phase matrices in size exclusion chromatography for the separation of proteins. To find the application of agarose for the separation of oil/water emulsion and protein, herein hydrophobic derivative of the seaweed biopolymer [M-W (1.27 +/- 0.17) x 10(-5) g/mol; sulphate content (0.29 +/- 0.09) %, gel strength (2242 +/- 21) g/cm(2)] is prepared by reacting the biopolymer with stearic acid and was used to prepare a composite membrane on polyester fabric. The oil and BSA rejection performance of the composite membrane was greater than 98%. The rejection rate increased with the increase in polymer content in the respective membranes for both oil/water and protein separation. The composite membrane showed a stable oil/water emulsion and protein separation performance over a period of six hours. Due to the biodegradable nature of the major components of the membrane, it has the potential for industrial applications.
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| 3. |
- Ganesan, Sivarasan, et al.
(författare)
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Preparation and Characterization of Salsalate-Loaded Chitosan Nanoparticles : In Vitro Release and Antibacterial and Antibiofilm Activity
- 2022
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Ingår i: Marine Drugs. - : MDPI AG. - 1660-3397. ; 20:12
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Tidskriftsartikel (refereegranskat)abstract
- The controlled-release characteristic of drug delivery systems is utilized to increase the residence time of therapeutic agents in the human body. This study aimed to formulate and characterize salsalate (SSL)-loaded chitosan nanoparticles (CSNPs) prepared using the ionic gelation method and to assess their in vitro release and antibacterial and antibiofilm activities. The optimized CSNPs and CSNP-SSL formulation were characterized for particle size (156.4 +/- 12.7 nm and 132.8 +/- 17.4 nm), polydispersity index (0.489 +/- 0.011 and 0.236 +/- 132 0.021), zeta potential (68 +/- 16 mV and 37 +/- 11 mV), and entrapment efficiency (68.9 +/- 2.14%). Physicochemical features of these nanoparticles were characterized using UV-visible and Fourier transform infrared spectroscopy and X-ray diffraction pattern. Scanning electron microscopy studies indicated that CSNPs and CSNP-SSL were spherical in shape with a smooth surface and their particle size ranged between 200 and 500 nm. In vitro release profiles of the optimized formulations showed an initial burst followed by slow and sustained drug release after 18 h (64.2 +/- 3.2%) and 48 h (84.6 +/- 4.23%), respectively. Additionally, the CSNPs and CSNP-SSL nanoparticles showed a sustained antibacterial action against Staphylococcus aureus (15.7 +/- 0.1 and 19.1 +/- 1.2 mm) and Escherichia coli (17.5 +/- 0.8 and 21.6 +/- 1.7 243 mm). Interestingly, CSNP-SSL showed better capability (89.4 +/- 1.2% and 95.8 +/- 0.7%) than did CSNPs in inhibiting antibiofilm production by Enterobacter tabaci (E2) and Klebsiella quasipneumoniae (SC3). Therefore, CSNPs are a promising dosage form for sustained drug delivery and enhanced antibacterial and antibiofilm activity of SSL; these results could be translated into increased patient compliance.
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| 4. |
- Halakarni, Mahaveer A., et al.
(författare)
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Design of selective and self-cleaning iron aminoclay thin film nanocomposite membranes
- 2023
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Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 456
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Tidskriftsartikel (refereegranskat)abstract
- Selective separation using efficient high-performance nanofiltration membranes has the potential for widespread application in multiple fields, including dye desalination, industrial wastewater treatment, and resource recovery from different feed streams. This study focused on the design of selective and self-cleaning nanofiltration membranes by incorporating iron aminoclay nanoparticles in a piperazine-based polyamide active layer supported on an ultrafiltration PAN substrate. Fe-AC nanoparticles and thin film nanocomposites (TFNC) were characterized for their morphology, surface chemistry, roughness, and surface area. In terms of wettability/hydrophilicity, TFNC membranes with Fe-AC incorporated had the lowest contact angle of 33.5 degrees, while that of the pristine TFNC0 membrane was 60.5 degrees. They also had a higher surface negative zeta potential and smoother surface morphology. The TFNC membranes also exhibited higher water fluxes and enhanced selectivity towards molecular separation compared to the control membranes. The water flux of the optimized AC polyamide membrane, TFNC3, was 19.70 +/- 0.5 LMH (L. m- 2.h-1), while that of the pristine TFNC0 membrane was 4.85 +/- 0.6 LMH at 4 bar. 98.0-99.0 % rejection of model organic moieties was achieved at a constant flux (Congo red, Eriochrome Black T, methylene blue, Rhodamine 6G, and Crystal violet). When simulated wastewater was purified, the Fe-AC TFNC showed 98.0 % rejection of dyes and 20.0 % rejection of inorganic salts. In long-term filtration studies (>210 h) using simulated wastewater spiked with multiple foulants, >98.0 % rejection of organic matter and foulants was recorded with a stable long-term flux profile. A leaching study confirmed that the membranes were structurally stable, even after the self-cleaning process and at elevated temperatures, without any significant reduction in flux or rejection. Comparing the fouling performance between TFNC3 membranes and commercial reverse osmosis (RO) membranes, the FDR and Flux Recovery Ratio (FRR) values of commercial RO membranes were 58.0 % and 73.0 %, while those of TFNC3 were 47.0 % and 97.0 %, respectively. The results show that the membranes have lower fouling values and higher FRR values when iron clay is present. These results demonstrate the potential of the membranes for effective pre-treatment of various industrial wastewaters and selective separation.
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| 5. |
- Halakarni, Mahaveer A., et al.
(författare)
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Forward osmosis process for energy materials recovery from industrial wastewater with simultaneous recovery of reusable water : a sustainable approach
- 2023
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Ingår i: Materials Today Sustainability. - : Elsevier BV. - 2589-2347. ; 22
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a biopolymer-based forward osmosis (FO) membrane was used in combination with an easily recoverable and reusable draw solution (DS) for a simultaneous recovery of high-quality water and value-added products from industrial wastewater. Simultaneous wastewater dewatering resulted in a highly concentrated sludge that was reused as the electrode material. In this study, 86.92% dewatering was achieved using an easily recyclable mixture of ethylenediaminetetraacetic acid disodium (EDTA-2Na) with Triton X-100 micelles as the DS and a chitosan membrane with FO. The compatible membrane and the DS showed a flux of 5e6 L m-2 h-1 and a 0.008 +/- 0.002 mol m-2 h-1 reverse solute flux with a retention of >99.0% for all organic pollutants from the chosen real-world wastewater. The recovered DS after the third use showed a >83.57% and >78.84% constant flux retention for deionizedand tannery wastewater as feed. In long-term tests with simulated wastewaters containing various contaminants, they showed >99.0% retention of organics and modern foulants and long-term stability (96 h). At the end of the FO process, sludge with different concentrations of organic wastes was recovered. The recovered solid sludge was carbonized (800 0C) and used as the electrode material in a supercapacitor with a specific capacitance of 165 F/g at a current density of 0.5 A/g.
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| 6. |
- Hoogendoorn, Billy W., et al.
(författare)
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Formation of Different Zinc Oxide Crystal Morphologies Using Cellulose as Nucleation Agent in the Waste Valorization and Recycling of Zn-Ion Batteries
- 2023
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Ingår i: Rare Metal Technology 2023. - Cham : Springer.
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Konferensbidrag (refereegranskat)abstract
- The formation of zinc oxide particles of different hierarchical morphologies was investigated. By performing elemental analysis on samples extracted from the supernatant solution during precipitations yielding two distinctly different morphologies, the consumption of zinc ions was used to follow the liquid-to-solid phase formation. While a rapid Zn-ion consumption was synonymous with the formation of predominantly oxygen terminated flower-shaped ZnO-particles, with half of the zinc ions being precipitated during the first minute, less than 10% of the zinc ions were converted to sea urchin-shaped ZnO-particles (with mixed terminations) after 1 min of the reaction. The unique ZnO-particle morphologies may therefore be related to the precipitation rates, which can be further explored as a tool for understanding how ZnO-particles with differently facetted surfaces form. Interestingly, the different formation rates remained with identical patterns when 0.5 g/L cellulose (0.005 wt%) was added to the reactions as nucleating agent for improved yields. The controlled formation of specific functional ZnO-particle surfaces is an important method for recycling inexpensive zinc waste from batteries to high value materials useful in a variety of catalytic applications.
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| 7. |
- Kumar, Radhakrishnan Naresh, et al.
(författare)
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Old Landfill Leachate and Municipal Wastewater Co-Treatment by Sequencing Batch Reactor Combined with Coagulation-Flocculation Using Novel Flocculant
- 2023
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Ingår i: Sustainability. - : MDPI AG. - 2071-1050. ; 15:10
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Tidskriftsartikel (refereegranskat)abstract
- The use of novel flocculants in combination with a sequencing batch reactor (SBR) for the treatment of landfill leachate and municipal wastewater has been shown to be an effective method for reducing polluted effluents. Co-treatment of landfill leachate with a mixture of municipal wastewater was performed at 5%, 10%, 15% and 20% in SBR and effluent was treated by coagulation-flocculation. SBR with 6 d hydraulic retention time (HRT) and 30 d solids retention time (SRT) removed 58 to 70% COD, 86 to 93% ammonia, 76 to 83% nitrate and 69 to 95% phosphate. Coagulation-flocculation with different dosages of alum and ferric chloride with polyacrylamide grafted gum ghatti (GGI-g-PAM) as a novel flocculant was used for chemical oxygen demand (COD), turbidity, total suspended solids (TSS) and color removal. Maximum COD removal was at 20% leachate, which was 74% with alum at 2800 mg/L and 77% with ferric chloride at 470 mg/L. Alum and ferric chloride with GGI-g-PAM flocculant removed 96% and 82% of turbidity and 80% and 82% TSS, respectively. At 20% leachate, combined treatment with SBR and coagulation-flocculation resulted in the total removal of 89% COD, 83% ammonia, 82% nitrate 98% turbidity and 93% TSS with alum. The combined treatment with ferric chloride resulted in a removal of 90% COD, 86% ammonia, 83% nitrate, 98% turbidity and 94% TSS. Except for nitrate combined treatment with both the coagulants at 20% landfill leachate to municipal wastewater ratio removed COD, ammonia, phosphate and TSS to a level that met international standards for discharges to inland surface water. As such, the use of new flocculants with SBR can help reduce water pollution from landfill leachate and municipal wastewater. In addition to coagulation-flocculation, other physico-chemical processes can also be studied as post-treatment options for the co-treatment of wastewater mixture.
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| 8. |
- Paidi, Murali Krishna, et al.
(författare)
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3D Natural Mesoporous Biosilica-Embedded Polysulfone Made Ultrafiltration Membranes for Application in Separation Technology
- 2022
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Ingår i: Polymers. - : MDPI AG. - 2073-4360. ; 14:9
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Tidskriftsartikel (refereegranskat)abstract
- Diatoms are the most abundant photosynthetic microalgae found in all aquatic habitats. In the extant study, the spent biomass (after lipid extraction) of the centric marine diatom Thalassiosira lundiana CSIRCSMCRI 001 was subjected to acid digestion for the extraction of micro composite inorganic biosilica. Then, the resulting three-dimensional mesoporous biosilica material (diatomite) was used as a filler in polysulfone (PSF) membrane preparation by phase inversion. The fabricated PSF/diatomite composite membranes were characterized by SEM-EDX, TGA, and ATR-IR, and their performances were evaluated. The number of pores and pore size were increased on the membrane surface with increased diatomite in the composite membranes as compared to the control. The diatomite composite membranes had high hydrophilicity and thermal stability, lower surface roughness, and excellent water permeability. Membranes with high % diatomite, i.e., PSF/Dia(0.5), had a maximum water flux of 806.8 LMH (Liter/m(2)/h) at 20 psi operating pressure. High-diatomite content membranes also exhibited the highest rejection of BSA protein (98.5%) and rhodamine 6G (94.8%). Similarly, in biomedical rejection tests, the PSF/Dia(0.5) membrane exhibited a maximum rejection of ampicillin (75.84%) and neomycin (85.88%) at 20 Psi pressure. In conclusion, the mesoporous inorganic biosilica material was extracted from spent biomass of diatom and successfully used in filtration techniques. The results of this study could enhance the application of natural biogenic porous silica materials in wastewater treatment for water recycling.
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| 9. |
- Praveena, Rangasamy, et al.
(författare)
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Structural Activity and HAD Inhibition Efficiency of Pelargonidin and Its Glucoside—A Theoretical Approach
- 2022
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Ingår i: Molecules. - : MDPI. - 1431-5157 .- 1420-3049. ; 27:22
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Tidskriftsartikel (refereegranskat)abstract
- Anthocyanins are an important pharmaceutical ingredient possessing diet regulatory, antioxidant, anticancer, antidiabetic, anti-obesity, antimicrobial, and anti-inflammatory properties. Pelargonidin is an important anthocyanin-based orange-red flavonoid compound used in drugs for treating hypoglycemia, retinopathy, skeletal myopathy, etc. The main sources of pelargonidin are strawberries and food products with red pigmentation. There is a lack of evidence for supporting its use as an independent supplement. In the present study, pelargonidin and pelargonidin-3-O-glucoside are studied for their structural properties using quantum chemical calculations based on density functional theory. The results confirmed that the parent compound and its glycosylated derivative acted as good electron donors. Electrostatic potential, frontier molecular orbitals, and molecular descriptor analyses also substantiated their electron donating properties. Furthermore, based on the probability, a target prediction was performed for pelargonidin and pelargonidin-3-O-glucoside. Hydroxyacyl-coenzyme A dehydrogenase was chosen as an enzymatic target of interest, since the presence work focuses on glucuronidated compounds and their efficacy over diabetes. Possible interactions between these compounds and a target with nominable binding energies were also evaluated. Further, the structural stability of these two compounds were also analyzed using a molecular dynamics simulation.
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| 10. |
- Reddy, C. Nagendranatha, et al.
(författare)
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Review of microplastic degradation : Understanding metagenomic approaches for microplastic degrading organisms
- 2023
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Ingår i: Polymer testing. - : Elsevier BV. - 0142-9418 .- 1873-2348. ; 128, s. 108223-
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Forskningsöversikt (refereegranskat)abstract
- Environmental problems caused by plastic pollution are among the most pressing issues of our time. In recent years, metagenomics has become a powerful tool for understanding the microbial communities responsible for plastic biodegradation. In this review, recent developments and trends in metagenomics are discussed, and a comprehensive overview of the metagenomic methodology, analysis, and comparison of plastic-degrading bacteria is provided. In addition, the environmental consequences of plastic degradation are discussed, such as the impact on soil, water, and air quality, as well as the potential health risks posed by ingesting and inhaling microplastics. Possible solutions to the plastic degradation problem, such as using biodegradable materials and implementing recycling programs, are also explained. This review highlights the potential impact of metagenomics on the development of sustainable solutions to plastic pollution.
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