Synthesize rGO-Ag NPs nanocomposite by a simple physical method and applying in water treatment

2022 ◽  
Author(s):  
Rafal Al-Assaly ◽  
Amer Al-Nafiey
2019 ◽  
Vol 48 (5) ◽  
pp. 431-438 ◽  
Author(s):  
Margarita Ivanovna Skiba ◽  
Viktoria Vorobyova

Purpose This paper aims to propose a simple, eco-friendly method for obtaining colloidal solutions of silver nanoparticles (Ag NPs) by using of contact non-equilibrium low-temperature plasma in presents polysorbate-80 and to assess their antibacterial activity in composite materials (beads) for water treatment process. Design/methodology/approach Silver nanoparticles were prepared in aqueous AgNO3 solution by using of contact non-equilibrium low-temperature plasma in the present of nonionic surfactant polysorbate-80 (Tween 80) as capping agent. Ultraviolet–visible (UV) spectroscopy, X-ray diffraction and zeta potential analysis were used to study the formation and properties of silver nanoparticles. Findings The formation of silver colloidal solutions in the presence of capping agent under plasma discharge is characterized by the presence of peak λmax = 380 – 402 nm in the spectra. The addition of sodium alginate into the reaction mixture allows synthesizing stable colloidal silver solutions. The average size of formed silver particles is up to 50 nm. Ag NPs exhibited an excellent bactericidal activity against both gram-positive and gram- negative bacteria. Composite beads prepared using nonionic surfactant were found to be effective in disinfecting the Staphylococcus aureus to different extents. Research limitations/implications Further studies are necessary for confirmation of the practical application, especially of the toxicity of Ag NPs, as well as the sorption properties of the alginate beads with Ag NPs. Practical implications The method provides a simple and practical solution to improving the synthesis of colloidal solutions of Ag NPs for water treatment process. Originality/value Contact nonequilibrium low-temperature plasma can be used as an effective technique for synthesis of nanomaterials.


RSC Advances ◽  
2015 ◽  
Vol 5 (101) ◽  
pp. 83286-83294 ◽  
Author(s):  
Daisy Setyono ◽  
Suresh Valiyaveettil

Efficient extraction of Ag NPs and Au NPs using polyethyleneimine coated porous ethyl cellulose microcapsules.


2016 ◽  
Vol 842 ◽  
pp. 461-466
Author(s):  
Satriawan Dini Hariyanto ◽  
Tutik Sriani ◽  
Gunawan Setia Prihandana

Due to the increase of industrial activities both at local and national level, the quality of water in Indonesia is significantly degraded by time. Heavy metal wastes from industrial activities have become serious contaminants in the water. The contamination dangers human’s health since most people living near the river-bank still use the water to fulfill their daily needs. In this paper, we present the fabrication of Hydroxyapatite (HA) disc as a filtration medium in waste water treatment system. HA is one of biomaterial which can be derived from animal’s bone and is capable to absorb dangerous heavy-metal contaminants such as lead (Pb) in the water. Our produced HA was made by extracting cortical bovine bones into cortical bone HA powder. The cortical bovine bones were processed using physical method by heating the bones at 900oC to gained powder then followed by forming green bodies and sintering at 1000oC and 1400oC. Those powders were then pressed into a disc form and will be used as filtration media in HA modular purifier. SEM/EDX results show the disk surface has interconnected micropores and Ca/P ratio value on sintered HA disc at 1000oC and 1400oC are 2.20 and 1.85, respectively.


2004 ◽  
Vol 58 (7-8) ◽  
pp. 343-350 ◽  
Author(s):  
Vladana Rajakovic ◽  
Dejan Skala

An important step in waste water treatment is the removal of oil from an O/W emulsion and the separation of oil and water into two phases, a process usually called demulsification. Modern methods of oil removal from waste water were described in the present study. Typical demulsification techniques include thermal, electrical, chemical, acoustic, or mechanical methods of emulsion treatment. The freeze/thaw process was found to be very effective for demulsification. In the freeze/thaw process, water removal from the W/O emulsion depends on the initial oil content, freezing temperature, freezing time, thawing rate and temperature. The described method is a non-destructive and physical method of emulsion treatment and because there is no addition of chemical agents there is no problem of further waste water treatment, which usually exists when chemicals are applied for demulsification. Different methods for oil content determination in the O/W emulsion were also applied and compared in this study (gravimetric, volumetric, measurement of oxygen consumption and emulsion pH, IR analysis of the emulsion, electro analytical measurement).


2019 ◽  
Vol 16 (3(Suppl.)) ◽  
pp. 0689
Author(s):  
Mohammad Et al.

           Biosynthesis of nanoparticles has received considerable attention due to the growing need to develop environmentally benign nanoparticle synthesis processes that do not use toxic chemicals. Therefore, biosynthetic methods employing both biological agents such as bacteria and fungus or plant extracts have emerged as a simple and a viable alternative to chemical synthetic and physical method .It is well known that many microbes produce an organic material either intracellular or extracellular which is playing important role in the remediation of toxic metals through reduction of metal ions and acting as interesting Nano factories. As a result, in the present study Ag NPs were synthesized by two methods biosynthetic technique using supernatant of Corynebacterium glutamicum that isolated from soil and green synthesis method by using plant extracts of fresh green plants.Ag NPs which synthesized by two methods were investigated visually by monitoring the color shift of reaction mixture from pale yellow to brown color, UV-Visible spectrophotometer was used to measure maximum absorbance of synthesized Ag NPs. The nanoparticles synthesized from Corynebacterium glutamicum exhibited maximum antimicrobial activity against selected pathogenic and environmental strains more than Ag NPs synthesized by green synthesis method from Spinacia oleracea, Malva parviflora and Eruca sativa. plant extracts


2018 ◽  
Vol 30 (1) ◽  
pp. 91
Author(s):  
Muhammad T. Malik ◽  
Talal Tariq ◽  
Abid H. Khan ◽  
Hameed Ullah ◽  
Muhammad Imran ◽  
...  

Pakistan is the 6th largest producer of mangoes which are known world over for their superior traits but export of mangoes from Pakistan is quite limited due to post-harvest diseases like anthracnose and stem-end rot (SER) mainly caused by Colletotrichum gloeosporioides and Lasiodiplodia theobromae, respectively. These diseases are aggravating day by day due to environmental changes in mango producing region of Pakistan. Quarantine of mangoes through physical methods like Hot Water Treatment (HWT) is always preferred by the foreign markets because of its high effectiveness in reducing the post-harvest diseases. During 2012-13, keeping in view the importance of HWT, a comprehensive study was conducted to standardize the temperature and dip duration levels for HWT along with a fungicide named Nativo (Trifloxystrobin + Tebuconazole) @ 0.3g/L of water for mango Cvs. Sindhri, S.B. Chaunsa, Fajri and Sufaid Chaunsa using newly developed HWT facility at Agricultural Mechanization Research Institute, Multan for the control of post-harvest diseases with a little focus on other fruit quality parameters as well. HWT resulted in better marketability of fruits due to uniform peel color development and visual quality rating (VQR). Control of (SER) with either of both high levels of temperature (54°C) and dip duration (06minutes) simultaneously or any of one high level along was noted in all the tested varieties with 77.27 to 85.26% disease reduction in contrast to control of anthracnose which was effectively minimized with the range of 77.24 to 90.36% through low temperature (52°C) and low dip level (03minutes) in case of Sindhri and S.B. Chaunsa while 52°C for 06 minutes and 54°C for 06 minutes showed good performance in case of Cvs. Fajri and Sufaid Chaunsa, respectively. Surely, this study developed the understanding of mango industry stake holders with efficient use of safe and cheaper physical method i.e. HWT to control post-harvest diseases to enhance the mango export from Pakistan.


2020 ◽  
Vol 0 (2) ◽  
pp. 21-25
Author(s):  
Nikolay Dubenok ◽  
Andrey Novikov ◽  
Sergei Borodychev ◽  
Maria Lamskova

At the stage of water treatment for irrigation systems, the efficiency capture coarse and fine mechanical impurities, as well as oil products and organic compounds affects the reliability of the equipment of the irrigation network and the safety of energy exchange processes in irrigated agricultural landscapes. The violation of work irrigation system can cause disruptions in irrigation schedules of agricultural crops, crop shortages, degradation phenomena on the soil and ecological tension. For the combined irrigation system, a water treatment unit has been developed, representing a hydrocyclone apparatus with a pipe filter in the case. For the capacity of 250 m3/h the main geometrical dimensions of hydrocyclone have been calculated. To organize the capture petroleum products and organic compounds, it has been proposed a modernization of a hydrocyclone unit, consisting in dividing the cylindrical part of the apparatus into two section. The first is section is for input irrigation water, the second one is for additional drainage of clarified irrigation water after sorption purification by the filter, placed on the disk and installed coaxially with the drain pipe and the pipe filter.


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