Fabrication of core–shell α-MnO2@polydopamine nanocomposites for the efficient and ultra-fast removal of U(vi) from aqueous solution

2019 ◽  
Vol 48 (3) ◽  
pp. 971-981 ◽  
Author(s):  
Jianjun Wang ◽  
Junping Ma ◽  
Chenlu Zhang ◽  
Xing Li ◽  
Shuang Song ◽  
...  

The development of functional nanoparticles with ultra-fast and high adsorption capacities is an important strategy for wastewater treatment.

2021 ◽  

<p>An adsorbent was prepared from Mangosteen shell using sulphuric acid and sodium bicarbonate as modifiers. Bicarbonate treated mangosteen shell (BTMC) was characterized using FT- IR, SEM, EDAX and XRD data. The Freundlich adsorption isotherm model gives a good fit. The maximum adsorption capacities of BTMC were found to be 58.48 mg g-1 and 49.75 mg g-1 for Pb (II) and. Hg (II). Adsorption of Pb (II) and Hg (II) followed pseudo-second-order kinetics. The adsorption mechanism was explained using the Weber and Morris's intra-particular diffusion process. Batch mode studies with synthetic wastewater suggest that BTMC can be efficiently used in wastewater treatment.</p>


2020 ◽  
Vol 12 (3) ◽  
pp. 441-448 ◽  
Author(s):  
Yanlin Li ◽  
Jun Ma ◽  
Yixing Yuan

Two-dimension magnetic double layer hydroxide nanoparticles (Ca–Al/Fe LDH) were synthesized by the hydrothermal method. Here, we demonstrate a potential method for efficient chromium removal using Ca–Al/Fe LDH as the adsorbent in water treatment. It was found that Cr(VI) could be successfully eliminated using the Ca–Al/Fe LDH. The method achieved extremely fast removal of Cr(VI) from water with high adsorption capacities. As-prepared Ca–Al/Fe LDH had a high specific surface area and anti-agglomeration property, which contributed to preventing nanometer metal particles from conglomerating during the adsorption process. The recycling studies indicated that Ca–Al/Fe LDH exhibited intense chromium absorption in simulated high levels of pollution wastewater. This modified synthetic approach could extend the application of Ca–Al/Fe LDH for heavy metal control by enhancing their adsorption and desorption capacity in wastewater treatment. Furthermore, the modified synthetic method could be used to produce a suite of stabilized, non-toxic chemical magnetic nanoparticles, and could be used for industrial production.


2021 ◽  
Vol 13 (5) ◽  
pp. 2641
Author(s):  
Siyao Bian ◽  
Shuang Xu ◽  
Zhibing Yin ◽  
Sen Liu ◽  
Jihui Li ◽  
...  

In this study, sequential KMnO4-promoted oxidative pyrolysis and H2O2 oxidation were employed to upgrade the adsorption capacities of durian shell biochar for methylene blue (MB) and tetracycline (TC) in an aqueous solution. It was found that the KMnO4/H2O2 co-modification was greatly influenced by pyrolysis temperature and the optimal temperature was 300 °C. Moreover, a low concentration of H2O2 enabled the improvement of the adsorption capabilities greatly with the catalysis of pre-impregnated manganese oxides, addressing the shortcoming of single H2O2 modification. The co-modified biochar exhibited high adsorption capabilities for MB and TC, remarkably surpassed KMnO4- and H2O2- modified biochars as well as pristine biochar. The increase of adsorption capabilities could be mainly contributed to the incorporation of MnOx and carboxyl by KMnO4-promoted oxidative decomposition and Mn-catalyzed H2O2 oxidation. This would provide a novel and efficient method for preparing highly adsorptive biochar using sequential KMnO4-promoted oxidative pyrolysis and H2O2 oxidation.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Adedibu C. Tella ◽  
Janet T. Bamgbose ◽  
Vincent O. Adimula ◽  
Mary Omotoso ◽  
Sunday E. Elaigwu ◽  
...  

AbstractThe interaction of eosin B dye from aqueous solution with MIL-100(Fe) and functionalized MIL-100(Fe) metal–organic frameworks (MOFs) is reported in this study. MIL-100(Fe) was prepared and functionalized with thioglycolic acid (TH) and ethylenediammine (ED) separately by incorporating the thiol (–SH) and the amine (–NH2) group of the functionalizing agents into the open metal sites of the MIL-100(Fe) to obtain the acidic (TH-MIL-100) and basic (ED-MIL-100) forms of the MOF respectively. Characterization of the MOFs was done by melting point analysis, elemental analysis, spectroscopic techniques, scanning electron microscopy (SEM), and powdered X-ray diffraction (PXRD) analysis. The adsorption experiments were carried out at different conditions such as pH, adsorbent dosage, contact time, temperature, and initial concentration of the dye to estimate the optimum conditions and the maximum adsorption capacities. Adsorption capacities were observed to increase in the order of ED-MIL-100 < MIL-100 < TH-MIL-100, while the TH-MIL-100 was the most effective in the removal process due to acid–base interaction between the acidic thiol group (–SH) and the alkaline medium of eosin B dye solution. The Langmuir Isotherm was seen to fit well to adsorption data obtained for all three adsorbent materials studied, and adsorption processes followed the pseudo-second order kinetics. This study, therefore, indicates the suitability of functionalization of MIL-100(Fe) towards improving its adsorption capacity.


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