scholarly journals Optimization of operational parameters for the treatment of roof-harvested rainwater with biologically synthesised nanosilver coated on sand

Author(s):  
Farhana Anoob ◽  
V. Meera

Abstract Rainwater is a major source of drinking water in developing countries. Roof-harvested rainwater is generally microbiologically contaminated and thus need to be treated effectively to meet drinking standards. Filtration of rainwater with silver nanoparticles coated on sand enhances the microbial removal efficiency. In this study, the filtration parameters of treating rainwater with biologically synthesized nanosilver coated sand are optimized. Of the various synthesis methods, the biological method of was chosen due to benefits such as cost-effectiveness and eco-friendly nature. Silver nanoparticles was synthesised using with papaya fruit extract and then coated on sand. The synthesized nanosilver coated sand was subjected to characterization methods such as Energy Dispersive Spectroscopy and X-Ray Diffraction analysis. With silver coated sand as control, multiple long duration tests were performed to treat rainwater with nanosilver coated sand to find the optimal values for filtration parameters such as filter bed depth and Empty Bed Contact Time (EBCT). The crystallite size of the nanosilver coated sand was found to be 43.8 nm. The optimal values for filter bed depth and EBCT was found to be 12 cm and 15minutes respectively. The rainwater treated with nanosilver coated sand met drinking water standards IS 10500: 2012 until the media got exhausted.

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2475
Author(s):  
Amirah Shafilla Mohamad Kasim ◽  
Arbakariya Bin Ariff ◽  
Rosfarizan Mohamad ◽  
Fadzlie Wong Faizal Wong

Silver nanoparticles (AgNPs) have been found to have extensive biomedical and biological applications. They can be synthesised using chemical and biological methods, and coated by polymer to enhance their stability. Hence, the changes in the physico-chemical characteristics of AgNPs must be scrutinised due to their importance for biological activity. The UV-Visible absorption spectra of polyethylene glycol (PEG) -coated AgNPs displayed a distinctive narrow peak compared to uncoated AgNPs. In addition, High-Resolution Transmission Electron Microscopy analysis revealed that the shapes of all AgNPs, were predominantly spherical, triangular, and rod-shaped. Fourier-Transform Infrared Spectroscopy analysis further confirmed the role of PEG molecules in the reduction and stabilisation of the AgNPs. Moreover, dynamic light scattering analysis also revealed that the polydispersity index values of PEG-coated AgNPs were lower than the uncoated AgNPs, implying a more uniform size distribution. Furthermore, the uncoated and PEG-coated biologically synthesised AgNPs demonstrated antagonisms activities towards tested pathogenic bacteria, whereas no antagonism activity was detected for the chemically synthesised AgNPs. Overall, generalisation on the interrelations of synthesis methods, PEG coating, characteristics, and antimicrobial activity of AgNPs were established in this study.


Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1525
Author(s):  
Sergey Vorobyev ◽  
Elena Vishnyakova ◽  
Maxim Likhatski ◽  
Alexander Romanchenko ◽  
Ivan Nemtsev ◽  
...  

Carey Lea silver hydrosol is a rare example of very concentrated colloidal solutions produced with citrate as only protective ligands, and prospective for a wide range of applications, whose properties have been insufficiently studied up to now. Herein, the reactivity of the immobilized silver nanoparticles toward oxidation, sulfidation, and sintering upon their interaction with hydrogen peroxide, sulfide ions, and chlorocomplexes of Au(III), Pd(II), and Pt(IV) was investigated using SEM and X-ray photoelectron spectroscopy (XPS). The reactions decreased the number of carboxylic groups of the citrate-derived capping and promoted coalescence of 7 nm Ag NPs into about 40 nm ones, excluding the interaction with hydrogen peroxide. The increased nanoparticles form loose submicrometer aggregates in the case of sulfide treatment, raspberry-like micrometer porous particles in the media containing Pd(II) chloride, and densely sintered particles in the reaction with inert H2PtCl6 complexes, probably via the formation of surface Ag-Pt alloys. The exposure of Ag NPs to HAuCl4 solution produced compact Ag films along with nanocrystals of Au metal and minor Ag and AgCl. The results are promising for chemical ambient temperature sintering and rendering silver-based nanomaterials, for example, for flexible electronics, catalysis, and other applications.


Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1936 ◽  
Author(s):  
M. A. Abu-Saied ◽  
Mohamed Elnouby ◽  
Tarek Taha ◽  
Muhammad El-shafeey ◽  
Ali G. Alshehri ◽  
...  

The wide distribution of infections-related pathogenic microbes is almost related to the contamination of food and/or drinking water. The current applied treatments face some limitations. In the current study, k-carrageenan polymer was used as supporting material for the proper/unreleased silver nanoparticles that showed strong antimicrobial activity against six pathogenic bacteria and yeast. The bio-extract of the pupa of green bottle fly was used as the main agent for the synthesis of silver nanoparticles. The qualitative investigation of biologically synthesized silver nanoparticles was determined using UV-Vis spectrophotometric analysis; however, the size of nanoparticles was in range of 30–100 nm, as confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and particle size analyzer. The proper integration of silver nanoparticles into the polymeric substrate was also characterized through fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), SEM, and tensile strength. The antimicrobial activity of k-carrageenan/silver nanoparticles against Gram positive, Gram negative, and yeast pathogens was highly effective. These results indicate the probable exploitation of the polymeric/nanoparticles composite as an extra stage in water purification systems in homes or even at water treatment plants.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2034
Author(s):  
Zubair Ahmed Ratan ◽  
Fazla Rabbi Mashrur ◽  
Anisha Parsub Chhoan ◽  
Sadi Md. Shahriar ◽  
Mohammad Faisal Haidere ◽  
...  

Since the early 1990s, nanotechnology has led to new horizons in nanomedicine, which encompasses all spheres of science including chemistry, material science, biology, and biotechnology. Emerging viral infections are creating severe hazards to public health worldwide, recently, COVID-19 has caused mass human casualties with significant economic impacts. Interestingly, silver nanoparticles (AgNPs) exhibited the potential to destroy viruses, bacteria, and fungi using various methods. However, developing safe and effective antiviral drugs is challenging, as viruses use host cells for replication. Designing drugs that do not harm host cells while targeting viruses is complicated. In recent years, the impact of AgNPs on viruses has been evaluated. Here, we discuss the potential role of silver nanoparticles as antiviral agents. In this review, we focus on the properties of AgNPs such as their characterization methods, antiviral activity, mechanisms, applications, and toxicity.


Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2400
Author(s):  
Afrah E. Mohammed ◽  
Lamya Ahmed Al-Keridis ◽  
Ishrat Rahman ◽  
Modhi O. Alotaibi ◽  
Rasha Saad Suliman ◽  
...  

The broad application of metal nanoparticles in different fields encourages scientists to find alternatives to conventional synthesis methods to reduce negative environmental impacts. Herein, we described a safe method for preparing silver nanoparticles (J-AgNPs) using Jatropha integerrima leaves extract as a reducing agent and further characterize its physiochemical and pharmacological properties to identify its therapeutic potential as a cytotoxic and antimicrobial agent. The biogenic synthesized J-AgNPs were physiochemically characterized by ultraviolet-visible spectroscopy, dynamic light scattering (DLS), transmission electron microscope (TEM), and energy-dispersive X-ray spectroscopy. HPLC-DAD, followed by LC/MS and the Fourier-transform infrared spectroscopy (FTIR), was applied to detect the biomolecules of J. integerrima involved in the fabrication of NPs. Furthermore, J-AgNPs and the ampicillin-nanocomposite conjugate were investigated for their potential antibacterial effects against four clinical isolates. Finally, cytotoxic effects were also investigated against cancer and normal cell lines, and their mechanism was assessed using TEM analysis and confocal laser scanning microscopy (LSM). Ag ions were reduced to spherical J-AgNPs, with a zeta potential of −34.7 mV as well as an average size of 91.2 and 22.8 nm as detected by DLS and TEM, respectively. HPLC GC/MC analysis identified five biomolecules, and FTIR suggested the presence of proteins besides polyphenolic molecules; together, these molecules could be responsible for the reduction and capping processes during NP formation. Additionally, J-AgNPs displayed a strong antibacterial effect, although the ampicillin conjugated form had a very weak antibacterial effect. Furthermore, the NPs caused a reduction in cell viability of all the treated cells by initiating ultrastructural changes and apoptosis, as identified by TEM and LSM analysis. Therefore, J-AgNPs can be formed using the leaf extract from the J. integerrima plant. Furthermore, J-AgNPs may serve as a candidate for further biochemical and pharmacological testing to identify its therapeutic value.


2018 ◽  
Vol 63 (1) ◽  
pp. 96-112 ◽  
Author(s):  
Barış Şimşek ◽  
İnci Sevgili ◽  
Özge Bildi Ceran ◽  
Haluk Korucu ◽  
Osman Nuri Şara

One of the ways of fully securing the presence of fresh water is water treatment process. Nanomaterials and nanotechnology offers an innovative solution for water treatment. In this study, physical, chemical and microbiological improvement rates of raw water were analyzed after filtration with graphene oxide. Graphene oxide's water treatment performance; silver nanoparticles, silver nanoparticles & graphene oxide composites that are commonly used in water treatment were compared with a traditional treatment method. When compared to the traditional method, there were improvements of 50 %, 40.7 %, 86.8 % and 45.5 % for color, TIC, TOC and hardness properties, respectively in water treatment by GO-based filtration with solid liquid ratio of 0.7 % (v/v). In water treatment with GO-Ag based filtration, 39.8 %, 69.8 %, 10.3 % and 28.6 % of improvements were obtained for TIC, TOC, hardness and LSI value compared to the conventional method. Both GO at 0.7 % (v/v) solid-liquid ratio and GO-Ag nanocomposites were successful in the number of total viable microorganisms and inhibiting microorganisms such as Escherichia coli fecal (gaita-infected), Salmonella typhi, Enterococcus faecalis, Pseudomona aeruginosa and Staphylococcus aureus. Among the studied parameters GO-Ag nanocomposites found to be the most suitable for drinking water treatment.


2013 ◽  
Vol 4 (2) ◽  
pp. 175-182 ◽  
Author(s):  
Rashmi R. Devi ◽  
Iohborlang M. Umlong ◽  
Bodhaditya Das ◽  
Kusum Borah ◽  
Ashim J. Thakur ◽  
...  

Author(s):  
Boguslaw Buszewski ◽  
Viorica Railean Plugaru ◽  
Pawel Pomastowski ◽  
Anatoli Sidorenco

Silver nanoparticles (AgNPs), as a material with attractive properties, has received interest worldwide by the implementation of synthesis particles at nano-size. AgNPs has triggered intense research on the production of nanoparticles using different synthesis methods due actual and future application. The increasing attention of AgNPs resulted in the growth and development of nanoparticles synthesis methods. Recently, various approaches, including chemical and biological, have been used for them preparation. In order to obtain information about size, shape, or optical properties of nanoparticles, a broad range of analytical methods—microscopy, spectroscopy, and spectrometry techniques—have been used. AgNPs exhibit attractive antimicrobial properties against bacteria (Gram-positive and Gram-negative), fungi, and show also selective toxicity toward normal and cancerous cells. This chapter reviewed the methods of AgNPs synthesis, their characteristics, antimicrobial activity, and cytotoxicity against normal and tumor cells.


Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 606 ◽  
Author(s):  
Aneta Wesołowska ◽  
Paula Jadczak ◽  
Danuta Kulpa ◽  
Włodzimierz Przewodowski

The aim of this study was to determine how the addition of gold and silver nanoparticles to culture media affects the composition of essential oils extracted from Lavandula angustifolia propagated on MS media with the addition of 10 and 50 mg·dm−3 of gold (24.2 ± 2.4 nm) and silver (27.5 ± 4.8 nm) nanocolloids. The oil extracted from the lavender tissues propagated on the medium with 10 mg·dm−3 AgNPs (silver nanoparticles) differed the most with respect to the control; oil-10 compounds were not found at all, and 13 others were detected which were not present in the control oil. The addition of AuNPs (gold nanoparticles) and AgNPs to the media resulted in a decrease of lower molecular weight compounds (e.g., α- and β-pinene, camphene, δ-3-carene, p-cymene, 1,8-cineole, trans-pinocarveol, camphoriborneol), which were replaced by those of a higher molecular weight (τ- and α-cadinol 9-cedranone, cadalene, α-bisabolol, cis-14-nor-muurol-5-en-4-one, (E,E)-farnesol).


Sign in / Sign up

Export Citation Format

Share Document