scholarly journals Optimization and Application of Bioflocculant Passivated Copper Nanoparticles in the Wastewater Treatment

Author(s):  
Nkosinathi Goodman Dlamini ◽  
Albertus Kotze Basson ◽  
Viswanadha Srirama Rajasekhar Pullabhotla

Nanotechnology offers a great opportunity for efficient removal of pollutants and pathogenic microorganisms in water. Copper nanoparticles were synthesized using a polysaccharide bioflocculant and its flocculation, removal efficiency, and antimicrobial properties were evaluated. The synthesized nanoparticles were characterized using thermogravimetry, UV-Visible spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), powder X-ray diffraction, scanning electron microscope (SEM), and transmission electron microscope (TEM). The highest flocculation activity (FA) was achieved with the lowest concentration of copper nanoparticles (0.2 mg/mL) with 96% (FA) and the least flocculation activity was 80% at 1 mg/mL. The copper nanoparticles (CuNPs) work well without the addition of the cation as the flocculation activity was 96% and worked best at weak acidic, neutral, and alkaline pH with the optimal FA of 96% at pH 7. Furthermore, the nanoparticles were found to be thermostable with 91% FA at 100 °C. The synthesized copper nanoparticles are also high in removal efficiency of staining dyes, such as safranin (92%), carbol fuchsine (94%), malachite green (97%), and methylene blue (85%). The high removal efficiency of nutrients such as phosphate and total nitrogen in both domestic wastewater and Mzingazi river water was observed. In comparison to ciprofloxacin, CuNPs revealed some remarkable properties as they are able to kill both the Gram-positive and Gram-negative microorganisms.

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1125
Author(s):  
Nkosinathi Goodman Dlamini ◽  
Albertus Kotze Basson ◽  
Viswanadha Srirama Rajasekhar Pullabhotla

Nanotechnology addresses numerous environmental problems such as wastewater treatment. Ground water, surface water and wastewater that is contaminated by toxic organic, inorganic solutes and pathogenic microorganisms can now be treated through the application of nanotechnology. The study reports iron@copper (Fe@Cu) nanoparticles, iron nanoparticles (FeNPs) and copper nanoparticles (CuNPs) synthesized using a bioflocculant in a green approach technique. Characterization of the as-synthesized materials was achieved using analytical techniques such as Fourier transform-Infrared spectroscopy (FT-IR), Thermogravimetric analysis (TGA), Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), UV-Vis spectroscopy (UV-Vis) and X-ray diffraction (XRD). The presence of hydroxyl (–OH) and amine (–NH2) groups was shown by FT-IR spectroscopy studies and the as-synthesized material was shown to be thermostable. Elements such as oxygen, carbon, iron and copper were found to be abundant in Wt%. Absorption peaks were found between 200 and 390 nm wavelength and diffraction peaks at 2θ –29°, 33° and 35° for FeNPs, CuNPs and Fe@Cu, respectively. In their application, the effect of various parameters on the flocculation activity were evaluated. Both the CuNPs and (Fe@Cu) nanoparticles have shown the best flocculation activity at a concentration of 0.2 mg/mL with over 90% activity, while the dosage size with a concentration of 0.4 mg/mL was optimal for FeNPs. The FeNPs were found to be cation dependent, while CuNPs and Fe@Cu nanoparticles flocculate in the absence of a cation and flocculate both in acidic and alkaline pH. All the synthesized nanoparticles are thermostable and maintain flocculation activity above 80% at 100 °C. Both the Fe@Cu and CuNPs were found to be effective in removing dyes with the removal efficiency above 89% and were found to be effective in removal of chemical oxygen demand (COD) and biochemical oxygen demand (BOD) in Mzingazi river water and coal mine wastewater with over 80% removal efficiency. Moreover, the synthesized nanoparticles showed some remarkable antimicrobial properties when evaluated against Gram-positive and Gram-negative bacteria. The as-synthesized material was found to be safe to use at low concentration when verified against human embryonic cells (HEK293) and breast cancer cells (MCF7) and biodegradable.


2013 ◽  
Vol 734-737 ◽  
pp. 2528-2531
Author(s):  
Yu Mei Gong ◽  
Qing Liang ◽  
Jing Guo ◽  
Hong Zhang ◽  
Fu Cheng Guan

Anatase/brookite mixtured TiO2nanoparticles have been synthesized by using a two-step process through a chimie douce technique. The as-prepared powders were characterized by Fourier transform infrared (FT-IR) spectra, X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), and a nitrogen adsorption apparatus in multipoint Brunauer-Emmett-Teller (BET) method. The results indicated that the TiO2nanoparticles were composed of biphasial anatase/brookite mixtures, 38% anatase phase formed in quasi-spherical shape and 62% brookite phase formed in nanorod shape. The specific surface area, the average pore diameter, and the specific pore volume were 100.06 m2/g, 14.0 nm, and 0.561 cm3/g, respectively.


e-Polymers ◽  
2016 ◽  
Vol 16 (4) ◽  
pp. 313-322 ◽  
Author(s):  
Dun Chen ◽  
Tunsagnl Awut ◽  
Bin Liu ◽  
Yali Ma ◽  
Tao Wang ◽  
...  

AbstractFe3O4 nanoparticles (MNP) were coated with 3-aminopropyltriethoxy-silane (APTES), resulting in anchoring of primary amine groups on the surface of the particles, then four kinds of novel magnetic adsorbents (Fe3O4@SiO2-NH-HCGs) were formed by grafting of different heterocyclic groups (HCG) on amino groups via substitution reaction. These Fe3O4@SiO2-NH-HCGs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and energy disperse spectroscopy (EDS). The results confirmed the formation of Fe3O4@SiO2-NH-HCGs nanoparticles and the Fe3O4 core possessed superparamagnetism. Batch experiments were performed to evaluate adsorption conditions of Cu2+, Hg2+, Pb2+ and Cd2+. Under normal temperature and neutral condition, just 20 min, the removal efficiency of any Fe3O4@SiO2-NH-HCGs is more than 96%. In addition, these Fe3O4@SiO2-NH-HCGs have good stability and reusability. Their removal efficiency has no obvious decrease after being used seven times. After the experiments were finished, Fe3O4@SiO2-NH-HCGs were conveniently separated via an external magnetic field due to superparamagnetism. These results indicate that these Fe3O4@SiO2-NH-HCGs are potentially attractive materials for the removal of heavy metal ions from industrial wastewater.


2011 ◽  
Vol 299-300 ◽  
pp. 1020-1023 ◽  
Author(s):  
Ke Tang ◽  
Xin Hong

MFI-type(ZSM-5) zeolite nanocrystals with SiO2/Al2O3ratios of 100 has been synthesized through crystallization of gel in mesoporous system of carbon nanotubes(CNTS) with internal diameter of 20~30nm. Investigation by using X-ray diffraction (XRD), Fourier transform infrared (FT-IR), transmission electron microscope (TEM) and scanning electron microscope (SEM) shows that the nanocrystals possess the typical nanosized zeolites structural characteristics which is different from those of microsized zeolites. Compared with those of the corresponding sample synthesized in hydrothermal system, the bands of the nanosized sample are shifted slightly to lower or higher wavenumbers. The TEM images of the purified carbon nanotubes and nanosized ZSM-5 crystals after the removal of the carbon matrix suggest that clean and homogeneous carbon nanotubes have internal diameters of approximately 20~30 nm and the most crystal sizes are in the range 30~60nm. The SEM photograph verifies the existing of nanosized ZSM-5.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Kun Liu ◽  
Lianjie Zhu ◽  
Tengfei Jiang ◽  
Youguang Sun ◽  
Hongbin Li ◽  
...  

Mesoporous anatase TiO2micro-nanometer composite structure was synthesized by solvothermal method at 180°C, followed by calcination at 400°C for 2 h. The as-prepared TiO2was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and Fourier transform infrared spectrum (FT-IR). The specific surface area and pore size distribution were obtained from N2adsorption-desorption isotherm, and the optoelectric property of the mesoporous TiO2was studied by UV-Vis absorption spectrum and surface photovoltage spectra (SPS). The photocatalytic activity was evaluated by photodegradation of sole rhodamine B (RhB) and sole phenol aqueous solutions under simulated sunlight irradiation and compared with that of Degussa P-25 (P25) under the same conditions. The photodegradation preference of this mesoporous TiO2was also investigated for an RhB-phenol mixed solution. The results show that the TiO2composite structure consists of microspheres (∼0.5–2 μm in diameter) and irregular aggregates (several hundred nanometers) with rough surfaces and the average primary particle size is 10.2 nm. The photodegradation activities of this mesoporous TiO2on both RhB and phenol solutions are higher than those of P25. Moreover, this as-prepared TiO2exhibits photodegradation preference on RhB in the RhB-phenol mixture solution.


2014 ◽  
Vol 13 (03) ◽  
pp. 1450018 ◽  
Author(s):  
S. K. Kannan ◽  
M. Sundrarajan

In this study, the synthesis of a cerium oxide nanoparticle was carried out from Acalypha indica leaf extract. The synthesized nanoparticle was characterized by using X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX) and Transmission Electron Microscope (TEM) for structural confirmation. The studies clearly indicate that the synthesized CeO 2 nanoparticle is a crystalline material with particle size between 25–30 nm. Further analysis was carried out by Fourier Transform infrared spectroscopy (FT-IR), to provide evidence for the presence of Ce - O - Ce asymmetry stretching of the CeO 2 nanoparticle. Thermo Gravimetric and Differential Scanning Calorimetry analyses gave the thermal properties of cerium oxide nanoparticles. Antibacterial studies were conducted using the synthesized CeO 2. This result showed increasing rate of antibacterial behavior with gram positive and gram negative bacteria.


2021 ◽  
Author(s):  
Jia-Qi Di ◽  
Yu-Xuan Chen ◽  
Zhanhui Zhang

Abstract A simple calcination method has been developed to prepare potassium-doped carbon nitride (K-CN). The prepared K-CN was characterized and analyzed by fourier infrared spectroscopy (FT-IR), powder X-ray diffraction technology (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and other techniques. It has been proved to be a green and recyclable catalyst for Knoevenagel condensation of benzaldehydes with malononitrile. The reaction system has the characteristics of mild reaction conditions, simple operation, and environmental protection. The catalyst still maintains high catalytic activity and excellent chemical stability after being recycled for six times.


2021 ◽  
Author(s):  
Jayavel M ◽  
Venkatachalam J ◽  
RAMALAKSHMI N ◽  
SIVASANKARAN A

Abstract Functionalized metal oxide electrode material plays an important role in the energy application of the supercapacitor. In this work, the comparative study of super-capacitance performance of hafnium oxide (HfO2) and sulfonated hafnium oxide (S-HfO2) nanomaterials is reported. The HfO2 nanoparticles were synthesized by the precipitation method. Subsequently, the prepared HfO2 nanoparticles were functionalized using sulfuric acid (H2SO4). Further, the synthesized nanoparticles were characterized and confirmed by X-Ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, High-resolution transmission electron microscope (HR-TEM), Field-Emission scanning electron microscope (FE-SEM) and Energy Dispersive X-Ray spectroscopy (EDS) techniques. The electrochemical properties and ion transfer characteristics of the supercapacitor were investigated by the cyclic voltammeter (CV) and galvanostatic charge-discharge (GCD) experiments. Moreover, the internal resistances of the material (HfO2 and S-HfO2) were analysed using Electrochemical Impedance Spectroscopy


2013 ◽  
Vol 320 ◽  
pp. 114-118
Author(s):  
Li Zhong Bai ◽  
Dong Lin Zhao ◽  
Ji Ming Zhang ◽  
Feng Li

High quality graphene sheets (GSs) were prepared from natural graphite by oxidation, rapid thermal expansion and ultrasonic treatment. The morphology and structure of GSs were systematically investigated by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier tansform infrared spectroscopy (FT-IR) and Raman spectroscopy. It was found that the GSs electrode used in lithium-ion battery (LIB) exhibited a relatively high reversible capacity of 902 mA h/g at a current density of 50 mA/g. After 50 cycles, the reversible capacity was still kept at 734 mA h/g.


2021 ◽  
Author(s):  
Yan Chen ◽  
Yuemei Lan ◽  
Dong Wang ◽  
Guoxing Zhang ◽  
Wenlong Peng ◽  
...  

A series of Gd2-xMoO6:xEu3+(x=0.18-0.38) nanophosphors were synthesized by the solvothermal method. The properties of this nanophosphor were characterized by x-ray diffraction (XRD), transmission electron microscope (TEM), fluorescence spectra and diffuse...


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