Nik Rashida Nik Abdul Ghani; Siti Syakirah Sulaiman; Amina Tahreen; Mohammed Saedi Jami
Abstract
Arsenic contamination poses a major public health concern and harms the environment with its toxicity. Long term exposure to a high concentration of arsenic is harmful to human health as well as the environmental biodiversity. This study is aimed to fabricate and investigate the possibility of polyethersulfone-graphene ...
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Arsenic contamination poses a major public health concern and harms the environment with its toxicity. Long term exposure to a high concentration of arsenic is harmful to human health as well as the environmental biodiversity. This study is aimed to fabricate and investigate the possibility of polyethersulfone-graphene oxide-polyvinyl pyrrolidone (PES-GO-PVP) nanocomposite adsorptive membrane and use it to enhance the removal of arsenic from wastewater. The nanocomposite membrane in this study was fabricated via the non-solvent induced phase separation (NIPS) method with the addition of polyvinylpyrrolidone (PVP) as a pore-forming agent. Based on the characterization results of GO through Fourier-Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD) and Raman spectroscopy, the existence of high quantity of oxygen based functional groups with high degree of oxidation was observed, which indicated that the GO were well-synthesized. The characterization of the membrane indicated that the addition of GO and PVP could impact the membrane hydrophilicity and mechanical stability. Three adsorption parameters (initial concentration of arsenic, pH and contact time) were then optimized using a face-centred central composite design (FCCCD). The arsenic removal efficiency of 88.6 % was obtained with 55 mg/L of initial arsenic concentration, at pH 8 and 75 minutes of contact time between PES-GO-PVP membrane and the arsenic ion. The Langmuir isotherm model fitted the equilibrium data, describing the monolayer adsorption mechanism occurred on the surface of the membrane. Therefore, the results obtained in this study prove the suitability and promising potential of the nanocomposite membrane for effective removal of arsenic through adsorption.
Susarla Sastry
Abstract
Nanotechnology is getting an incredible drive due to the potential of manipulating metals into their nano size particles. The synthesis and characterization of nano particles using green technology have many applications. The wet chemical techniques used presently in the synthesis of nano particles are ...
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Nanotechnology is getting an incredible drive due to the potential of manipulating metals into their nano size particles. The synthesis and characterization of nano particles using green technology have many applications. The wet chemical techniques used presently in the synthesis of nano particles are deleterious along with flammable conditions. Silver nanoparticles have the capability of killing microbes in an effective manner. This paper explains about the green technology and pollution free methodology for synthesizing silver particles at nano scale using 1mM silver nitrate solution from the extracts of Carica papaya, Emblica officianalis, Azadirachta indica and Cocos nucifera. When the silver nanoparticles are synthesized the solution turns to brownish yellow colour. The tools used in the characterisation of silver nano particles are Ultra Violet - Visible absorption Spectroscopy and Field Emission Scanning Electron Microscopy. The solutions with silver nanoparticles showed the maximum absorption at 450 nm with Ultra Violet - Visible spectroscopy. It is found that C. Papaya and E. oficianalis showed the maximum absorbance of 0.578 and 0.59 respectively at 450 nm. The average range of the produced silver nano particles are analysed to be 5 – 70 nm with FESEM and the shape is examined to be spherical.