scholarly journals GREEN SYNTHESIS OF SILVER NANOPARTICLE USING GREEN TEA LEAVES EXTRACT FOR REMOVAL CIPROFLOXACIN (CIP) FROM AQUEOUS MEDIA

Author(s):  
Fatimah Q. Kadhim ◽  
Mohammed A. Atiya ◽  
Ahmed K. Hassan

This study examines the removal of ciprofloxacin in an aqueous solution using green tea silver nanoparticles (Ag-NPs). The synthesized Ag-NPs have been classified by the different techniques of SEM, AFM, BET, FTIR, and Zeta potential. Spherical nanoparticles with average sizes of 32 nm and a surface area of 1.2387m2/g are found to be silver nanoparticles. The results showed that the ciprofloxacin removal efficiency depends on the initial pH (2.5-10), CIP (2-15 mg/L), temperature (20-50°C), time (0-180 min), and Ag-NPs dosage (0.1-1g/L). Batch experiments revealed that the removal rate with ratio (1:1) (w/w) were 52%, and 79.8% of the 10 mg/L of CIP at 60, and 180 minutes, respectively with optimal pH=4. Kinetic models for adsorption and ciprofloxacin mechanism removal were also investigated, and kinetic analyzes showed adsorption to be a 3.8727kJ.mol-1 activation energy physical adsorption mechanism. The kinetic removal process, due to the low activation energy of 14.0606kJ.mol-1, is preferred the model of first-order after a physical diffusion-controlled reaction. Adsorption information from Langmuir, Freundlich, Temkin, and Dubinin models was followed, and the Dubinin isotherm model was the best-fitted model. the thermodynamic parameter ?G0 values at 20, 30, 40 and 50°C were (0.5163, -0.0691, -0.9589, -0.5927kJ/mol). The value of ?H0 and ?S0 were (12.713kJ/mol and 0.0422073kJ/mol.k) which indicated favorable and endothermic sorption. The presence and concentration of CIP in aqueous media were identified through UV analysis.

2021 ◽  
pp. 2832-2854
Author(s):  
Mohammed A. Atiya ◽  
Ahmed K. Hassan ◽  
Fatimah Q. Kadhim

     In the present investigation, the synthesis of copper nanoparticles from green tea was attempted and investigated for its capacity to adsorb drugs (Ciprofloxacin). The copper nanoparticles (Cu-NPs) were characterized by different techniques of analysis such as scanning electron microscopy (SEM) images, atomic force microscope (AFM),  blumenauer-emmer-teller (BET), fourier transform infrared (FTIR) spectroscopy, and zeta potentials techniques. Cu-NPs lie in the mesoporous material category with a diameter in the range of 2-50 nm. The aqueous solution was investigated for the removal of ciprofloxacin (CIP) with green tea-synthesized Cu-NPs. The results showed that ciprofloxacin efficiency depends on initial pH (2.5-10), CIP (2mg/L-15mg / L) dose, temperature (20 ° C-50 ° C); time (0-180 min) and Cu-NP dose (0.1g /L-1g /L). Spherical nanoparticles with an average size of 47nm and a surface area of 1.6562m2/g were synthesized. The batch experiment showed that 92% of CIP 0.01 mg/L were removed at a maximum adsorbent dose of 0.75 g/L, pH 4, 180 min, and an initial 1:1 rate (w / w) of CIP: Cu-NPs. Kinetic adsorption models and ciprofloxacin removal mechanisms were examined. The kinetic analysis showed that adsorption is a physical adsorption system with activation energy of 0.8409 kJ.mol-1. A pseudo-first-order model is preferred for the kinetic removal after the physically diffusing process due to the low activation energy of 13.221kJ.mol-1. On the other hand, Langmuir, Freundlich, Temkin, and Dubinin isotherm models were also studied; the equilibrium data were best fitted with Langmuir and Dubinin isotherm models with maximum adsorption capacity of 5.5279, and 1.1069 mg/g, respectively. The thermodynamic values of ∆G0 were -0.0166, -0.0691, -4.1084, and -0.7014 kJ/mol at 20, 30, 40, and 50 ° C, respectively. The values of ΔH0 and ΔS0 were 18.8603 kJ/mol and 0.0652kJ/mol.k, respectively. These values showed spontaneous and endothermic sorption. The presence of the CIP concentration in aqueous media was identified by UV-analysis.


Cellulose ◽  
2021 ◽  
Author(s):  
Nina Čuk ◽  
Martin Šala ◽  
Marija Gorjanc

Abstract The development of cellulose-based textiles that are functionalised with silver nanoparticles (AgNP), synthesised according to a green approach, and offer protection against ultraviolet (UV) radiation and pathogenic bacteria is very important today. In the present work we demonstrate the environmentally friendly approach to obtain such textile material by AgNP synthesis directly (in-situ) on cotton fabrics, using water extracts of plant food waste (green tea leaves, avocado seed and pomegranate peel) and alien invasive plants (Japanese knotweed rhizome, goldenrod flowers and staghorn sumac fruit) as reducing agents. The extracts were analysed for their total content of phenols and flavonoids and their antioxidant activity. The synthesised AgNP on cotton were round, of different size and amount depending on the reducing agent used. The highest amount of AgNP was found for samples where Japanese knotweed rhizome extract was used as reducing agent and the lowest where extracts of goldenrod flowers and green tea leaves were used. Regardless of the reducing agent used to form AgNP, all cotton samples showed excellent protection against E. coli and S. aureus bacteria and against UV radiation with UV protection factor values above 50. The best results for UV protection even after the twelve repetitive washing cycles were found for the sample functionalized with AgNP synthesised with an extract of the Japanese knotweed rhizome. Due to the presence of AgNP on cotton, the air permeability and thermal conductivity decreased. AgNP had no effect on the change in breaking strength or elongation of fabrics. Graphic abstract


2017 ◽  
Vol 6 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Wara Dyah Pita Rengga ◽  
Arie Yufitasari ◽  
Wismoyo Adi

The synthesis of silver nanoparticles with micro size is highly required in antibacterial fields. The biorefinery material is highly potential as a bioreductor which is applied in the synthesis of nanoparticles. The bioreductor is made from green tea leaves extraction using aquadest to extract its active substance, the catechin which is derived from polyphenol. The polyphenol can reduce the synthesis of silver nanoparticles naturally. The result of FTIR analysis from green tea leaves extract containing polyphenol shown in the uptake functional groups is -OH group located in 3425 cm-1, C=O group located in 1635 cm-1, C=C group located in 1527, and 1442 cm-1 , and C-O group located in 1234 cm-1. The precursors of AgNO3 was used as the main synthetic material. The synthetic condition was resulted from the reaction between the extraction of green tea extract and AgNO3 as the precursors in the variation of synthetizing time. The heating process during synthesizing is done in 50 ?C along with stirring to foster the creation of silver nanoparticles. The analysis result of XRD shows that silver nanoparticles has the diffraction peaks in the angle of 2 theta that are 44.08, 64.40, and 77.51. The types of silver nanoparticles is Ag0 nanoparticles with face-centered cubic crystal structure. Based on TEM analysis, the size and particle size distribution can be determined using image J. The distribution shows that the longer synthesizing time, the bigger nanoparticles produced. With synthesizing times at 24 hours, 6 hours, 3 hours, and 2 hours produce average particle size of 26.4 nm; 9.2 nm; 8.4 nm; and 7.4 nm respectively.


2021 ◽  
Author(s):  
Ola M. Gomaa ◽  
Amar Alrshim ◽  
Anindya Chanda

Abstract The present work aims to study the removal of Polyvinylpyrrolidone coated silver nanoparticles (PVP-Ag-NPs) using Aspergillus niger and depict the role of exopolysaccharides in the removal process. Our results show that the majority of PVP-Ag-NPs were attached to fungal pellets. About 74% and 88% PVP-Ag-NPs were removed when incubated with A. niger pellets and exopolysaccharide-induced A. niger pellets, respectively. Ionized Ag decreased by 553 and 1290 fold under the same conditions as compared to stock PVP-Ag-NP. PVP-Ag-PVP resulted in an increase in reactive oxygen species (ROS) in 24h. The UV-Visible spectrum shows the disappearance of Ag characteristic peak and the broadness of the spectrum suggested an increase in size. Dynamic Light Scattering results showed an increase in PVP-Ag-NPs size from 28.4 nm to 115.9 nm for A. niger pellets and 160.3 nm after removal by stress-induced A. niger pellets and further increased to 650.1 nm for in vitro EPS removal. Our findings show that EPS can be used for nanoparticle removal, by increasing the net size of nanoparticles in aqueous media, this will, in turn, facilitate its filtration through conventional filtration techniques commonly used at wastewater treatment plants.


2017 ◽  
Vol 53 (10) ◽  
pp. 3201-3209 ◽  
Author(s):  
Maryam Nakhjavani ◽  
V. Nikkhah ◽  
M. M. Sarafraz ◽  
Saeed Shoja ◽  
Marzieh Sarafraz

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2930 ◽  
Author(s):  
Agnieszka Tomczyk ◽  
Katarzyna Szewczuk-Karpisz ◽  
Zofia Sokołowska ◽  
Milena Kercheva ◽  
Emil Dimitrov

Due to the harmful effects of nanoparticles in the environment, their effective removal from aqueous media is of great importance. This paper described the research on the silver nanoparticles (Ag-NPs) sorption on biochars obtained from different feedstock types. The sorbents were produced through pyrolysis (double-barrel method) of the vineyard (BV), paulownia tree (BP), and tobacco (BT). BV exhibited the highest specific surface area, porosity, value of variable surface charge, and content of surface acidic functional groups among the used biochars. The pseudo-second order model best described the obtained adsorption kinetics, whereas the Freundlich model accounted for the registered adsorption data. The Ag-NPs removal was highly efficient in the case of BV, especially in the nanoparticle concentration range 50–500 mg/L. Thus, this biochar can be considered as an ecofriendly, effective, low-cost organic adsorbent, potentially used in the aqueous media purification.


2021 ◽  
Author(s):  
Ola M. Gomaa ◽  
Amar Elrshim ◽  
Anindya Chanda

Abstract The rapidly growing production and applications of Engineered Nanoparticles (ENPs) foresees a concomitant increase in the exposure of humans to their potential toxic effects through accidental release to the environment. Due to the limited and/or contaminated water resources, the need to re-use treated water has become imperative. The present work aims to study the removal of Polyvinylpyrrolidone coated silver nanoparticles (PVP-Ag-NPs) using Aspergillus niger and depict the role of exopolysaccharides in the removal process. Our results show that the majority of PVP-Ag-NPs were attached to fungal pellets. About 74% and 88% PVP-Ag-NPs were removed when incubated with A. niger pellets and exopolysaccharide-induced A. niger pellets, respectively. Ionized Ag decreased by 553 and 1290 fold under the same conditions as compared to stock PVP-Ag-NP. The increase in PVP-Ag-PVP concentrations resulted in an increase in reactive oxygen species (ROS) in 24h. The UV-Visible spectrum shows the disappearance of Ag characteristic peak and the broadness of the spectrum suggested an increase in size. Dynamic Light Scattering results showed an increase in PVP-Ag-NPs size from 28.4 nm to 115.9 nm for A. niger pellets and 160.3 nm after removal by stress-induced A. niger pellets and further increased to 650.1 nm for in vitro EPS removal. Our findings show that EPS can be used for nanoparticle removal, by increasing the net size of nanoparticles in aqueous media, this will, in turn, facilitate its filtration through conventional filtration techniques commonly used at wastewater treatment plants.


2019 ◽  
Vol 967 ◽  
pp. 161-167
Author(s):  
Hasri ◽  
Iwan Dini ◽  
Satria Putra Jaya Negara ◽  
Subaer

Silver nanoparticles act as anti-bacterial and anti-inflammatory. On the other hand, some plants contain reducing agents. Therefore, it is deemed necessary to know the potentiality of plant extracts such as green tea leaf extract on the synthesis of silver nanoparticles. The Methanol extract of green tea leaves serves as a reduction of AgNO3 solution. Determination of the optimum reaction time in forming nanosize using UV-Vis spectrophotometer every 30 minutes. Characterization of nanoparticles obtained using scanning electron microscopy (SEM) and particle size analyzer (PSA). The results showed that green tea leaf extract was able to reduce Ag + to silver nanoparticles at a reaction time of 90 minutes, the temperature of 70°C. Morphology is not uniform, tends to aggregate, and the size distribution of silver nanoparticles is 82.33-740.89 nm with an average diameter of 157.8 nm.


Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3800
Author(s):  
Rebaone Makaudi ◽  
Hugues Kamdem Paumo ◽  
Boniface Kamdem Pone ◽  
Lebogang Katata-Seru

This investigation reports the in situ growth of silver nanoparticles onto covalently bonded graphene oxide-chitosan, which serve as supported nanocatalysts for the NaBH4 reduction of 2,4-dinitrophenol in aqueous systems. Fumaryl chloride reacted with chitosan in an acidic environment to yield a tailored polymeric material. The latter was, in turn, treated with the pre-synthesised graphene oxide sheets under acidic conditions to generate the GO-functionalised membrane (GO-FL-CS). The adsorption of Ag+ from aqueous media by GO-FL-CS yielded a set of membranes that were decorated with silver nanoparticles (Ag NPs@GO-FL-CS) without any reducing agent. Various analytical tools were used to characterise these composites, including Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller surface area analysis, X-ray diffraction, scanning electron microscopy/energy-dispersive X-ray analysis, inductively coupled plasma-mass spectrometry, and transmission electron microscopy. The silver-loaded materials were further used for the remediation of 2,4-dinitrophenol from aqueous solutions under batch operation. The BET analysis revealed that the functionalisation of GO with chitosan and Ag NPs (average size 20–60 nm) resulted in a three-fold increased surface area. The optimised catalyst (Ag mass loading 16.95%) displayed remarkable activity with an apparent pseudo-first-order rate constant of 13.5 × 10−3 min−1. The cyclic voltammetry experiment was conducted to determine the nitro-conversion pathway. The reusability/stability test showed no significant reduction efficiency of this metal-laden composite over six cycles. Findings from the study revealed that Ag NPs@GO-FL-CS could be employed as a low-cost and recyclable catalyst to convert toxic nitroaromatics in wastewater.


2015 ◽  
Vol 8 (3) ◽  
pp. 2176-2188 ◽  
Author(s):  
Keisham Nanao Singh

This article reports on the Dielectric Relaxation Studies of two Liquid Crystalline compounds - 7O.4 and 7O.6 - doped with dodecanethiol capped Silver Nanoparticles. The liquid crystal molecules are aligned homeotropically using CTAB. The low frequency relaxation process occurring above 1 MHz is fitted to Cole-Cole formula using the software Dielectric Spectra fit. The effect of the Silver Nanoparticles on the molecular dipole dynamics are discussed in terms of the fitted relaxation times, Cole-Cole distribution parameter and activation energy. The study indicate a local molecular rearrangement of the liquid crystal molecules without affecting the order of the bulk liquid crystal molecules but these local molecules surrounding the Silver Nanoparticles do not contribute to the relaxation process in the studied frequency range. The observed effect on activation energy suggests a change in interaction between the nanoparticles/liquid crystal molecules.


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