Adsorption–desorption behavior of methylene blue onto aged polyethylene microplastics in aqueous environments

2021 ◽  
Vol 167 ◽  
pp. 112287
Author(s):  
Huimin You ◽  
Baoquan Huang ◽  
Changlin Cao ◽  
Xinping Liu ◽  
Xiaoli Sun ◽  
...  
2012 ◽  
Vol 518-523 ◽  
pp. 352-355
Author(s):  
Hui Liu ◽  
Hong Liang Li ◽  
Meng Xue Wang ◽  
Jing Jing Sang ◽  
Xiu Song Zhao

Methylene blue (MB) was used as model molecule to investigate the effects of surface properties and solvent pH values on the adsorption and desorption (or release) behaviors of mesoporous SBA-15 materials. It was found that the treatment of SBA-15 with a pH 7.8 aqueous solution can enhance the adsorption rate and capacity in comparison with the pristine SBA-15. The effect of pH values on MB releasing from the weak base treated SBA-15 and the pristine one have been studied and been compared in pH values range from 0.5 to 7.0. Both of them showed a maximum releasing rate at about pH 2 and all of the treated SBA-15 samples showed a higher releasing quantity than the pristine ones. The influence mechanisms of base treatment on the adsorption ability and that of pH values on the releasing properties of SBA-15 samples have been analyzed and been discussed based on the composition, the morphology, the surface area and pore size distribution and adsorption/desorption measurements.


2011 ◽  
Vol 194-196 ◽  
pp. 385-388
Author(s):  
Hong Juan Wang ◽  
Feng Qiang Sun ◽  
Ming Zhong Ren ◽  
Qing Wei Guo

Nanoporous SnO2with high photocatalytic activity has been successfully prepared by a photochemical method, using SnCl2aqueous solution as a precursor. The as-synthesized sample was characterized by XRD, N2 adsorption-desorption and UV-vis. The photocatalytic activity of the sample was evaluated by degrading methylene blue (MB) aqueous solution under the UV light source and was compared with that of the commercial titania (Degussa P25). The results showed that the produced SnO2can degrade MB solution quickly and has comparative photocatalytic performance with P25 for degrading MB. This facile method supplies an effective way to prepare SnO2photocatalyst.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sadia Ata ◽  
Sadaf Amin ◽  
Ismat Bibi ◽  
Ijaz-ul- Mohsin ◽  
Atif Islam ◽  
...  

Abstract In the present work, halloysite nano-clay (HNTs) based hydrogel was fabricated and their efficiency for the removal of methylene blue dye was studied. The hydrogel films were prepared with varying amount of halloysite nano-clay via facile solution casting method. Effect of halloysite clay on adsorption performance of composite was investigated. The hydrophobic thermoplastic synthetic polymer, polylactic acid (PLA) was blended with hydrophilic polymer polyvinyl alcohol (PVA) and HNTs to synthesize hydrogels. Swelling behavior and antimicrobial efficiency was also evaluated. The halloysite incorporating films showed excellent antibacterial activity. Swelling capacity of hydrogel with increased halloysite content was reduced due to increased crosslinking among polymer chains. Halloysite incorporated hydrogel exhibited higher adsorption ability as compared to film comprising of only PVA and PLA and dye removal followed pseudo first order kinetics. Film with 0.03 g HNTs rapidly attained adsorption-desorption equilibria and removed the dye completely within 30 min. Results confirmed that synthesized film could be potentially used for the removal of cationic dye and fabricated hydrogel film have promising potential for wastewater treatment since a higher adsorption capacity was observed for halloysite nano-clay incorporated hydrogel.


2012 ◽  
Vol 463-464 ◽  
pp. 543-547 ◽  
Author(s):  
Cheng Feng Li ◽  
Xiao Lu Ge ◽  
Shu Guang Liu ◽  
Fei Yu Liu

Core-shell structured hydroxyapatite (HA)/meso-silica was prepared and used as absorbance of methylene blue (MB). HA/meso-silica was synthesized in three steps: preparation of nano-sized HA by wet precipitation method, coating of dense silica and deposition of meso-silica shell on HA. As-received samples were characterized by Fourier transformed infare spectra, small angle X-ray diffraction, nitrogen adsorption-desorption isotherm and transmission electron microscopy. A wormhole framework mesostructure was found for HA/meso-silica. The specific surface area and pore volume were 128 m2•g-1 and 0.36 cm3•g-1, respectively. From the adsorption isotherm, HA/meso-silica with the great specific surface area exhibited a prominent adsorption capacity of MB (134.0 mg/g) in comparison with bare HA (0 mg/g). This study might shed light on surface modification of conventional low-cost adsorbents for removal of organic pollutants from aqueous solutions.


2014 ◽  
Vol 896 ◽  
pp. 541-544
Author(s):  
Is Fatimah ◽  
N. Nunani Yuyun

ZnO-SiO2/Laponite was prepared by sol-gel preparation procedure consit of SiO2 pillarization to laponite followed by ZnO dispersion by using zinc acetate as precursor. The obtained material was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), diffuse reflectance UV-Visible (DRUV-Vis) and N2 adsorption-desorption analysis. The photocatalytic performance of the amterial in methylene blue decolorization was also investigated. Compared with ZnO-SiO2 nanoparticles, it is concluded that ZnO-SiO2/Laponite possess higher photocatalytic activity which obey Temkin isotherm model.


2021 ◽  
Vol 21 (3) ◽  
pp. 1694-1702
Author(s):  
Mengke Zheng ◽  
Zhenguo Wu ◽  
Yang Wang ◽  
Nannan Chen ◽  
Zhaogang Teng ◽  
...  

In this paper, novel Ethylenediaminetetraacetic acid disodium salt (EDTA) functionalized magnetite/ chitosan nanospheres (Fe3O4/CS-EDTA) are synthesized by combining solvothermal method and chemical modification, and they are further applied as a kind of adsorbent to eliminate dye of methylene blue (MB) from wastewater. The properties as well as structure exhibited by the fabricated adsorbent are characterized through FTIR, XRD, TG and TEM, together with VSM. The impact exerted by sorption parameters (time of contact, initial dye concentration, temperature, etc.) on the adsorptions were evaluated in batch system. These results demonstrated that our magnetic materials held the adsorption capacity for MB of 256 mg g−1 (pH = 11), and the kinetic model of pseudo-second-order and the Langmuir model could make an effective simulation regarding the adsorption kinetics and isotherm, respectively. Besides, the external magnetic field can assist in easily separating dye adsorbed Fe3O4/CS-EDTA from solution for regeneration. The removal efficiency of recycled adsorbents remained above 92% in the 5th adsorption/desorption cycle. These superioritiesmake Fe3O4/CS-EDTA a high-efficientmultifunctional adsorbent for removing dyes from wastewater.


2014 ◽  
Vol 30 (3) ◽  
pp. 1183-1189 ◽  
Author(s):  
Tarik Ainane ◽  
Fatima Khammour ◽  
Mohammed Talbi ◽  
M’hamed Elkouali

2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
Juzheng Zhang ◽  
Xin Liu ◽  
Shanmin Gao ◽  
Quanwen Liu ◽  
Baibiao Huang ◽  
...  

A yellow/brown powder of(I2)nsensitized nanoporous TiO2was obtained via an hydrolysis with TiCl4and iodine hydrosol as raw material. I2nanoparticles in the hydrosol were used as seeds to initiate the nucleation of a precursory TiO2shell. The hybridized jumbles were further calcinated at different temperatures. The structure, crystallinity, morphology, and other physical-chemical properties of the samples are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2adsorption-desorption isotherms measurements, and UV-vis diffuse reflectance spectroscopy (DRS). The formation mechanism of these(I2)nsensitized nanoporous TiO2is discussed. Methylene blue solutions were used as model wastewater to evaluate the visible light photocatalytic activity of the samples. The results indicate that iodine can exist even in high-temperature calcination for iodine being encapsulated in the nanocavities inside TiO2. The degradation of methylene blue (MB) accorded with the first-order reaction model.


2021 ◽  
Author(s):  
Rachida Souidi ◽  
yasmina khane ◽  
Lahcen Belarbi ◽  
Smain Bousalem

Abstract In this work, the sawdust of vine wood (VW) was treated with sulfuric acid and used to adsorb methylene blue (MB) from aqueous solutions via a batch adsorption process. The characteristics of the adsorbent were determined by various analytical techniques such as Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) and Brunauer−Emmett−Teller (BET) N2 adsorption−desorption isotherms. The effects of various experimental parameters including sulfuric acid concentration, particle size of the adsorbent, pH of the solution, contact time, initial concentration, adsorbent dosage and temperature on adsorption of MB by activating sawdust were systematically investigated. The experimental results showed that the adsorption efficiency was increased with contact time and adsorbent dosage. The maximum removal efficiency was found after 180 min of solid/liquid contact with adsorbent doses of 1 g/l for sawdust. The isotherm and kinetic experimental data for MB adsorption on VW sawdust were best-fitted by Langmuir models and Pseudo-second-order, respectively. The calculated values of the entropy (ΔS°), enthalpy (ΔH°) and Gibbs energy (ΔG°) indicated that the adsorption process was exothermic in nature. These results suggest that the activated sawdust can be employed as a low-cost and environmentally friendly adsorbent for the treatment of wastewaters containing dyes.


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