scholarly journals Enrichment and recycling of Zn from electroplating wastewater as zinc phosphate via coupled coagulation and hydrothermal route

2021 ◽  
pp. 103664
Author(s):  
Rui Bian ◽  
Ting Su ◽  
Yidi Gao ◽  
Yu Chen ◽  
Suiyi Zhu ◽  
...  
Keyword(s):  
Zinc Phosphate ◽  
Hydrothermal Route ◽  
Electroplating Wastewater

scholarly journals Upcycling of Electroplating Sludge to Prepare Erdite-Bearing Nanorods for the Adsorption of Heavy Metals from Electroplating Wastewater Effluent

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1027 ◽  
Author(s):  
Yanwen Liu ◽  
Asghar Khan ◽  
Zhihua Wang ◽  
Yu Chen ◽  
Suiyi Zhu ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Effluent ◽  
Hydrothermal Route ◽  
Polyaluminum Chloride ◽  
Electroplating Wastewater ◽  
Facile Hydrothermal Route ◽  
Electroplating Sludge ◽  
Removal Efficiencies ◽  
Metallurgical Processes ◽  
Polyferric Sulfate

Electroplating sludge is a hazardous waste produced in plating and metallurgical processes which is commonly disposed of in safety landfills. In this work, electroplating sludge containing 25.6% Fe and 5.5% Co (named S1) and another containing 36.8% Fe and 7.8% Cr (S2) were recycled for the preparation of erdite-bearing particles via a facile hydrothermal route with only the addition of Na2S·9H2O. In the sludges, Fe-containing compounds were weakly crystallized and spontaneously converted to short rod-like erdite particles (SP1) in the presence of Co or long nanorod (SP2) particles with a diameter of 100 nm and length of 0.5–1.5 μm in the presence of Cr. The two products, SP1 and SP2, were applied in electroplating wastewater treatment, in which a small portion of Co in SP1 was released in wastewater, whereas Cr in SP2 was not. Adding 0.3 g/L SP2 resulted in the removal of 99.7% of Zn, 99.4% of Cu, 37.9% of Ni and 53.3% of Co in the electroplating wastewater, with residues at concentrations of 0.007, 0.003, 0.33, 0.09 and 0.002 mg/L, respectively. Thus, the treated electroplating wastewater met the discharge standard for electroplating wastewater in China. These removal efficiencies were higher than those achieved using powdered activated carbon, polyaluminum chloride, polyferric sulfate or pure Na2S·9H2O reagent. With the method, waste electroplating sludge was recycled as nanorod erdite-bearing particles which showed superior efficiency in electroplating wastewater treatment.

Proton Acidity and Proton Mobility in ECR-40, a Silicoaluminophosphate That Violates Löwenstein’s Rule

2019 ◽  
Author(s):  
Michael Fischer
Keyword(s):  
Density Functional ◽  
Water Clusters ◽  
Computational Study ◽  
Acid Catalyst ◽  
Ab Initio Molecular Dynamics ◽  
Brønsted Acidity ◽  
Hydrothermal Route ◽  
Proton Mobility ◽  
Brönsted Acidity ◽  
A Minor

<p>The silicoaluminophosphate zeotype ECR-40, which has the MEI topology, contains linkages of AlO<sub>4</sub> tetrahedra via a common oxygen atom, thereby violating the famous “Löwenstein’s rule”. Due to the proven existence of Al-O-Al linkages in this material, it constitutes an ideal model system to study the acidity and mobility of protons associated with such unusual linkages. In addition, their properties can be directly compared to those of protons associated with more common Si-O-Al linkages, which are also present in ECR-40. In this work, static density functional theory (DFT) calculations including a dispersion correction were employed to study the preferred proton sites as well as the Brønsted acidity of the framework protons, followed by DFT-based ab-initio molecular dynamics (AIMD) to investigate the proton mobility in guest-free and hydrated ECR-40. Initially, two different proton arrangements were compared, one containing both H[O6] protons associated with Al-O-Al linkages and H[O10] protons at Si-O-Al linkages, the other one containing only H[O10] protons. The former model was found to be thermodynamically favoured, as a removal of protons from the Al-O-Al linkages causes a local accumulation of negative charge. Calculations of the deprotonation energy showed a moderately higher Brønsted acidity of the H[O10] protons, at variance with previous empirical explanations, which attributed the exceptional performance of ECR-40 as acid catalyst to the presence of Al‑O‑Al linkages. The AIMD simulations (<i>T</i> = 298 K) delivered no appreciable proton mobility for guest-free ECR-40 and for low levels of hydration (one H<sub>2</sub>O per framework proton). Under saturation conditions, framework deprotonation occurred, leading to the formation of protonated water clusters in the pores. Pronounced differences between the two types of framework protons were observed: While the H[O10] protons were always removed from the Si-O-Al linkages, the Al-O-Al linkages remained mostly protonated, but deprotonation did occur to a minor extent. The observation of a degree of framework deprotonation of Al-O-Al linkages differs from the findings reported in a recent computational study of hydrated aluminosilicate zeolites with such linkages (Heard et al., <i>Chem. Sci.</i> <b>2019</b>, <i>10</i>, 5705), pointing to an influence of the overall framework composition. Further inspection of the AIMD results showed that a coordination of water molecules to framework Al atoms occurred in many cases, especially in the vicinity of the Al-O-Al linkages, sometimes resulting in a pronounced modification of the linkages through additional bridging oxygen atoms. Given the changes in the local structure, it can be expected that such modified linkages are especially prone to break upon dehydration. Thus, in addition to elucidating the deprotonation behaviour of protons associated with different types of linkages, the calculations also provide insights into possible reasons for the instability of Al-O-Al linkages, clarifying why Löwenstein’s rule is mostly obeyed in materials that are formed via a hydrothermal route.</p>

Fabrication of Morphology of One-dimensional Nano-γ-AlOOH via Hydrothermal Route

2009 ◽  
Vol 24 (3) ◽  
pp. 463-468 ◽  
Author(s):  
Guang-Wei LU ◽  
Qi YANG ◽  
Yi-Da DENG ◽  
Wen-Bin HU
Keyword(s):  
Hydrothermal Route ◽  
One Dimensional

Shape controllable synthesis of NdFeO3micro single crystals by a hydrothermal route

CrystEngComm ◽  
2014 ◽  
Vol 16 (5) ◽  
pp. 858-862 ◽  
Author(s):  
You Wang ◽  
Xuecheng Yan ◽  
Jun Chen ◽  
Jinxia Deng ◽  
Ranbo Yu ◽  
...  
Keyword(s):  
Single Crystals ◽  
Controllable Synthesis ◽  
Hydrothermal Route

Solvothermal Synthesis and Characterization of an One-Dimensional Zinc Phosphate

2002 ◽  
Vol 37 (2-3) ◽  
pp. 169-175 ◽  
Author(s):  
K. Yanxiong ◽  
L. Jianmin ◽  
Z. Yugen ◽  
H. Gaofei ◽  
J. Zheng ◽  
...  
Keyword(s):  
Solvothermal Synthesis ◽  
Zinc Phosphate ◽  
Synthesis And Characterization ◽  
One Dimensional

Thermal properties and fire behavior of a flexible poly(vinyl chloride) modified with complex of 3-aminotriazole with zinc phosphate

2021 ◽  
Vol 122 ◽  
pp. 103326
Author(s):  
K. Salasinska ◽  
K. Mizera ◽  
M. Celiński ◽  
P. Kozikowski ◽  
J. Mirowski ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Vinyl Chloride ◽  
Zinc Phosphate ◽  
Fire Behavior ◽  
Poly Vinyl Chloride

scholarly journals Towards Iron-Titanium Oxide Nanostructures from Ecuadorian Black Mineral Sands

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 122
Author(s):  
Karina J. Lagos ◽  
Bojan A. Marinkovic ◽  
Alexis Debut ◽  
Karla Vizuete ◽  
Víctor H. Guerrero ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Titanium Oxide ◽  
Low Cost ◽  
Mineral Resources ◽  
Added Value ◽  
Secondary Phases ◽  
Hydrothermal Route ◽  
Oxide Nanostructures ◽  
Transmission Electron ◽  
Pre Treatment

Ecuadorian black mineral sands were used as starting material for the production of iron-titanium oxide nanostructures. For this purpose, two types of mineral processing were carried out, one incorporating a pre-treatment before conducting an alkaline hydrothermal synthesis (NaOH 10 M at 180 °C for 72 h), and the other prescinding this first step. Nanosheet-assembled flowers and nanoparticle agglomerates were obtained from the procedure including the pre-treatment. Conversely, nanobelts and plate-like particles were prepared by the single hydrothermal route. The nanoscale features of the product morphologies were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. The ilmenite and hematite molar fractions, within the ilmenite-hematite solid solution, in the as-synthetized samples were estimated by Brown’s approach using the computed values of unit-cell volumes from Le Bail adjustments of X-ray powder diffraction (XRPD) patterns. The resulting materials were mainly composed of Fe-rich ilmenite-hematite solid solutions (hematite molar contents ≥0.6). Secondary phases, which possibly belong to lepidocrocite-like or corrugated titanate structures, were also identified. The current study demonstrated the feasibility of employing Ecuadorian mineral resources as low-cost precursors to synthesize high-added-value nanostructures with promising applications in several fields.

Dy-doped MoO3 nanobelts synthesized via hydrothermal route: Influence of Dy contents on the structural, morphological and optical properties

2021 ◽  
pp. 160070
Author(s):  
Sapan Kumar Sen ◽  
Supria Dutta ◽  
Lincoln Paik ◽  
Tapash Chandra Paul ◽  
M.S. Manir ◽  
...  
Keyword(s):  
Optical Properties ◽  
Hydrothermal Route
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