Fabrication of attapulgite/carbon composites from spent bleaching earth for the efficient adsorption of methylene blue

RSC Advances ◽  
2015 ◽  
Vol 5 (48) ◽  
pp. 38443-38451 ◽  
Author(s):  
Jie Tang ◽  
Bin Mu ◽  
Li Zong ◽  
Maosong Zheng ◽  
Aiqin Wang

In this work, one-dimensional attapulgite/carbon composites were prepared by a one-step carbonization process using the residual organic matter of spent bleaching earth as a low-cost available carbon precursor.

Author(s):  
An Nang Vu ◽  
Anh Mai Tran ◽  
Nghi Tuyet Nguyen ◽  
Duyen My Ngoc Lam ◽  
Phong Pham Nam Le ◽  
...  

In this work, nanohybrid of zinc oxide/ cellulose nanocrystals (ZnO/CNC) was successfully prepared by using a low cost and green method for photocatalytic degradation of methylene blue (MB). CNC had been derived through the hydrolysis reaction by citric/hydrochloric acid from the pure cellulose isolated from Vietnamese Nypa fruticans trunk. The obtained CNC with carboxyl groups could act as a stabilizing and supporting agent to anchor ZnO nanoparticles. The chemical and crystal structures, morphology, thermal and photocatalytic properties of the ZnO/CNC nanohybrid were characterized by FESEM, FTIR, XRD, FESEM, BET, EDX, TGA, DRS and photocatalytic tests. Analyses of FTIR spectra, XRD, and FESEM indicated that the ZnO nanocrystals with the size of 50 nm formed and loaded on the surface of CNC. The TGA analysis demonstrated that the ZnO loading sample (ZnO/CNC) had the thermal degradation onset temperature higher than that of neat CNC. ZnO/CNC cuold be absorpted ultraviolet light and have high value of specific surface area (SBET), based on the DRS spectra and the nitrogen adsorption – desorption isotherms analysis, respectively. ZnO/CNC displayed more photocatalytic activity than pure ZnO upon degradation of methylene blue due to strong interaction between the CNC and ZnO nanoparticles. The maximum degradation of MB was about 95% in 150 minutes for the ZnO/CNC.


2016 ◽  
Vol 74 (11) ◽  
pp. 2534-2540 ◽  
Author(s):  
Ali Belhaine ◽  
Mouffok Redouane Ghezzar ◽  
Fatiha Abdelmalek ◽  
Kamel Tayebi ◽  
Abdelhamid Ghomari ◽  
...  

This work is about the valorization of spent bleaching earth (SBE) at low cost from the AFIA oil refinery in Algeria's western region. The biowaste has been burned to eliminate the oil traces, then it has been valorized in two ways: (i) chemically, using phosphoric acid to obtain SBEC and (ii) thermally at 750 °C to create SBEH. The obtained materials were used for the first time as biosorbents in the wastewater treatment field. The three biomaterials show very interesting adsorption properties, with specific surfaces of 194.2, 784.6 and 888.5 m2 g−1 for SBE, SBEC and SBEH, respectively. The analysis has revealed that the obtained materials are alumino-silicates. The three biowastes have been used to remove methylene blue dye from water. The dye was totally eliminated by a physisorption mechanism in the presence of 1 g L−1 of each biowaste after 8, 10, 20 min of contact time. The highest correlation coefficient (R2 = 0.99) was related to the Langmuir isotherm, indicating a good fit with this model, and explaining the biosorption as a monolayer process. According to this model, the adsorption capacities were 123.3, 185.2 and 188.7 mg g−1 for SBE, SBEH and SBEC, respectively. This study shows that SBE can be used as an alternative to commercial adsorbents for dye removal from water.


2020 ◽  
Author(s):  
Baojian Xiong ◽  
Yue Li ◽  
Yin Wei ◽  
Søren Kramer ◽  
Zhong Lian

Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance and low cost of phenols. Here, we report a dual nickel/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryl triflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60 examples). Furthermore, it displays low sensitivity to steric effects demonstrated by the synthesis of a 2,2’disubstituted biaryl and a fully substituted aryl product. The widespread presence of phenols in natural products and pharmaceuticals allow for straightforward late-stage functionalization, illustrated with examples such as Ezetimibe and tyrosine. NMR spectroscopy and DFT calculations indicate that the nickel catalyst is responsible for activating the aryl triflate, while the palladium catalyst preferentially reacts with the aryl tosylate.


2020 ◽  
Vol 27 (10) ◽  
pp. 1616-1633 ◽  
Author(s):  
Oana Cristina Duta ◽  
Aurel Mihail Ţîţu ◽  
Alexandru Marin ◽  
Anton Ficai ◽  
Denisa Ficai ◽  
...  

Polymeric materials, due to their excellent physicochemical properties and versatility found applicability in multiples areas, including biomaterials used in tissue regeneration, prosthetics (hip, artificial valves), medical devices, controlled drug delivery systems, etc. Medical devices and their applications are very important in modern medicine and the need to develop new materials with improved properties or to improve the existent materials is increasing every day. Numerous reasearches are activated in this domain in order to obtain materials/surfaces that does not have drawbacks such as structural failure, calcifications, infections or thrombosis. One of the most used material is poly(vinylchloride) (PVC) due to its unique properties, availability and low cost. The most common method used for obtaining tubular devices that meet the requirements of medical use is the surface modification of polymers without changing their physical and mechanical properties, in bulk. PVC is a hydrophobic polymer and therefore many research studies were conducted in order to increase the hydrophilicity of the surface by chemical modification in order to improve biocompatibility, to enhance wettability, reduce friction or to make lubricious or antimicrobial coatings. Surface modification of PVC can be achieved by several strategies, in only one step or, in some cases, in two or more steps by applying several techniques consecutively to obtain the desired modification / performances. The most common processes used for modifying the surface of PVC devices are: plasma treatment, corona discharge, chemical grafting, electric discharge, vapour deposition of metals, flame treatment, direct chemical modification (oxidation, hydrolysis, etc.) or even some physical modification of the roughness of the surface.


2018 ◽  
Vol 74 (7) ◽  
pp. III_415-III_422
Author(s):  
Yasushi ISHIGURO ◽  
Guangyu CUI ◽  
Tomonari FUJISAWA ◽  
Katsuhito YASUFUKU ◽  
Shinya OKUMURA ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shella Permatasari Santoso ◽  
Vania Bundjaja ◽  
Artik Elisa Angkawijaya ◽  
Chintya Gunarto ◽  
Alchris Woo Go ◽  
...  

AbstractNitrogen-grafting through the addition of glycine (Gly) was performed on a metal- phenolic network (MPN) of copper (Cu2+) and gallic acid (GA) to increase its adsorption capacity. Herein, we reported a one-step synthesis method of MPN, which was developed according to the metal–ligand complexation principle. The nitrogen grafted CuGA (Ng-CuGA) MPN was obtained by reacting Cu2+, GA, and Gly in an aqueous solution at a molar ratio of 1:1:1 and a pH of 8. Several physicochemical measurements, such as Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), N2 sorption, X-ray diffraction (XRD), and thermal gravimetry analysis (TGA), were done on Ng-CuGA to elucidate its characteristics. The analysis revealed that the Ng-CuGA has non-uniform spherical shaped morphology with a pore volume of 0.56 cc/g, a pore size of 23.25 nm, and thermal stability up to 205 °C. The applicational potential of the Ng-CuGA was determined based on its adsorption capacity against methylene blue (MB). The Ng-CuGA was able to adsorb 190.81 mg MB per g adsorbent at a pH of 6 and temperature of 30 °C, which is 1.53 times higher than the non-grafted CuGA. Detailed assessment of Ng-CuGA adsorption properties revealed their pH- and temperature-dependent nature. The adsorption capacity and affinity were found to decrease at a higher temperature, demonstrating the exothermic adsorption behavior.


Sign in / Sign up

Export Citation Format

Share Document