scholarly journals Removal efficiency and mechanism of bio-treated coking wastewater by catalytic ozonation using MnO2 modified with anionic precursors

2020 ◽  
Vol 26 (5) ◽  
pp. 200394-0
Author(s):  
Jie Zhang ◽  
Ben Dong ◽  
Ding Ding ◽  
Shilong He ◽  
Sijie Ge
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Catalytic Performance ◽  
Catalytic Ozonation ◽  
Relative Content ◽  
Precipitation Method ◽  
Coking Wastewater ◽  
Physiochemical Properties ◽  
Removal Efficiencies

In this paper, MnO<sub>2</sub> catalyst were firstly prepared and modified by four kinds of anionic precursors (i.e., NO<sub>3</sub><sup>-</sup>, AC<sup>-</sup>, SO<sub>4</sub><sup>2-</sup> and Cl<sup>-</sup>) through redox precipitation method. After that, bio-treated coking wastewater (BTCW) was prepared and employed as targeted pollutants to investigate the catalytic ozonation performance of prepared-MnO<sub>2</sub> catalyst was investigated and characterized by the removal efficiencies and mechanism of the prepared bio-treated coking wastewater (BTCW), which was employed as the targeted pollutants. Specifically, the effects of specific surface area, crystal structure, valence state of Mn element and lattice oxygen content on catalytic activity of MnO<sub>2</sub> materials were characterized by BET, XRD and XPS, respectively. Results showed that COD of BTCW could be removed 47.39% under MnO<sub>2</sub>-NO<sub>3</sub><sup>-</sup> catalyst with 2 h reaction time, which was much higher than that of MnO<sub>2</sub>-AC<sup>-</sup> (3.94%), MnO<sub>2</sub>-SO<sub>4</sub><sup>2-</sup> (12.42%), MnO<sub>2</sub>-Cl<sup>-</sup> (12.94%) and pure O<sub>3</sub> without catalyst (21.51%), respectively. So, MnO<sub>2</sub>-NO<sub>3</sub><sup>-</sup> presented the highest catalytic performance among these catalysts. The reason may be attributed to a series of better physiochemical properties including the smaller average grain, the larger specific surface area and active groups, more crystal defect and oxygen vacancy, higher relative content of Mn<sup>3+</sup> and adsorbed oxygen (O<sub>ads</sub>) than that of another three catalysts.

Synthesis of Novel Core-Shell Structured Hydroxyapatite/Meso-Silica for Removal of Methylene Blue from Aqueous Solutions

2012 ◽  
Vol 463-464 ◽  
pp. 543-547 ◽  
Author(s):  
Cheng Feng Li ◽  
Xiao Lu Ge ◽  
Shu Guang Liu ◽  
Fei Yu Liu
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Low Cost ◽  
Nitrogen Adsorption ◽  
Precipitation Method ◽  
Core Shell ◽  
Adsorption Desorption

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.

Preparation of Adsorbent from Blue Coke Powder and its Application in Coking Wastewater

2011 ◽  
Vol 695 ◽  
pp. 553-556
Author(s):  
Yu Hong Tian ◽  
Xin Zhe Lan ◽  
Qiu Li Zhang ◽  
Juan Qin Xue ◽  
Yong Hui Song ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Removal Rate ◽  
Nitrogen Concentration ◽  
Ammonia Nitrogen ◽  
Raw Material ◽  
Coking Wastewater ◽  
Adsorption Time ◽  
Coke Powder

The low-cost blue coke industrial by-product, blue coke powder was used as raw material for the production of porous carbons adsorbent by steam activating at temperature of 800°C under the atmosphere of N2 for 60 minutes. The specific surface area and pore properties of the adsorbent were characterized by using N2 adsorption-desorption isotherms. Furthermore, the adsorption effects of the adsorbent for ammonia nitrogen in coking wastewater were investigated in terms of particle size, dosage of absorbent and adsorption time. The results show that the specific surface area is 620.94m2/g, the total pore volume is 0.4442cm3/g and the average mesopore size is 4.5808nm, the adsorbent possesses predominant mesoporous structures. In aeration, the removal rate of ammonia nitrogen can reach to 39.5% under the conditions of the ammonia nitrogen concentration of 625mg/L, the dosage of adsorbent 10g/L at the adsorption time of 60 minutes.

Synthesis and Photocatalytic Property of BiVO4/FeVO4 Composite Novel Photocatalyst

2010 ◽  
Vol 129-131 ◽  
pp. 784-788 ◽  
Author(s):  
Min Wang ◽  
Qiong Liu ◽  
Dong Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Photocatalytic Property ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Triclinic Phase ◽  
Xrd Patterns

BiVO4/FeVO4 composite photocatalyst samples were prepared by calcining the mixture of FeVO4 and BiVO4 precusor which were prepared through liquid phase precipitation method for further increasing the photocatalytic efficiency of FeVO4. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microsoope（SEM）and specific surface area (BET). The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange (MO) solution under visible light. The XRD patterns indicate that BiVO4/FeVO4 composite photocatalysts consist of triclinic phase and the lattice was not distorted beacause of doping Bi. But the morphology change greatly and the specific surface area has little change. In the experimental conditions used, the optimal photocatalytic activity for all the prepared samples was reached when BiVO4 doping was 22 at%. The degradation rate of MO was increased by 20％ or so than that of pure FeVO4.

The Influence of Sinterng Temperature on the Phase, Microstructure and Textual Properties of Hollow Hydroxyapatite Microspheres

2011 ◽  
Vol 239-242 ◽  
pp. 2274-2279 ◽  
Author(s):  
Ying Chun Wang ◽  
Wen Hai Huang ◽  
Ai Hua Yao ◽  
De Ping Wang
Keyword(s):  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Sintering Temperature ◽  
Total Pore Volume ◽  
Precipitation Method ◽  
Simple Method ◽  
Air Atmosphere

A simple method to prepare hollow hydroxyapatite (HAP) microspheres with mespores on the surfaces is performed using a precipitation method assisted with Li2O-CaO-B2O3(LCB) glass fabrication process. This research is concerned with the effect of sintering temperature on the microstructure evolution, phase purity, surface morphology, specific surface area, and porosity after sintering process. The microspheres were sintered in air atmosphere at temperatures ranging from 500 to 900 °C. The starting hollow HAP microspheres and the sintered specimens were characterized by scanning electron microscope, X-ray diffractometer, specific surface area analyzer, and Hg porosimetry, respectively. The as-prepared microspheres consisted of calcium deficient hydroxyapatite. The results showed that the as-prepared hollow HAP microspheres had the highest specific surface areas, and the biggest total pore volume. The pore size distribution of the as-prepared hollow HAP microspheres were mainly the mesopores in the range of 2～40 nm. The specific surface area and total pore volume of hollow HAP microspheres decreased with increasing sintering temperature. Whereas the mean pore size increased with increasing sintering temperature. It showed that at 700°C, Ca-dHAP decomposes into a biphasic mixture of HAP and β-calcium phosphate(TCP).

Influence of Zinc Oxide Nanograins on Properties of Epoxidized Natural Rubber Vulcanizates

2017 ◽  
Vol 748 ◽  
pp. 79-83 ◽  
Author(s):  
Rudeerat Suntako
Keyword(s):  
Mechanical Properties ◽  
Zinc Oxide ◽  
Natural Rubber ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Epoxidized Natural Rubber ◽  
Precipitation Method ◽  
Cure Characteristics ◽  
Permanent Set

Zinc oxide (ZnO) nanograins are synthesized by precipitation method filled epoxidized natural rubber compared to conventional ZnO. The synthesized ZnO nanograins are characterized by X-ray diffraction and transmission electron microscopy and found that average primary size of ZnO synthesized around 40 nm and the specific surface area of 28.72 m2 g-1. Furthermore, the cure characteristics, rubber mechanical properties and permanent set were investigated. The obtained results are found that the ZnO nanograins significantly affected to cure characteristics, rubber mechanical properties and permanent set. This is due to small grain size and large specific surface area.

scholarly journals Investigation of the hydrothermal aging of an Mn-based mullite SmMn2O5 catalyst of NO oxidation

RSC Advances ◽  
2017 ◽  
Vol 7 (77) ◽  
pp. 49091-49096 ◽  
Author(s):  
Lina Xue ◽  
Ka Xiong ◽  
Haijun Chen ◽  
Kyeongjae Cho ◽  
Weichao Wang
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Catalytic Performance ◽  
No Oxidation ◽  
Hydrothermal Aging

The decrease in the catalytic performance for NO oxidation of the Mn-based mullite SmMn2O5 after being subjected to hydrothermal aging was mainly caused by an ∼3-fold decrease in its specific surface area (BET).

The Influence of Biogenic and Synthetic Starting Materials on the Properties of Porous Hydroxyapatite Bioceramics

2014 ◽  
Vol 614 ◽  
pp. 11-16 ◽  
Author(s):  
Kristine Salma-Ancane ◽  
Liga Stipniece ◽  
Janis Locs ◽  
Vitalijs Lakevičs ◽  
Zilgma Irbe ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Precipitation Method ◽  
Porous Hydroxyapatite ◽  
Calcium Carbonates ◽  
Porous Bodies ◽  
Wide Range ◽  
Egg Shells ◽  
Viscous Mass

The aim of this study was to investigate the influence of biogenic and synthetic starting materials on properties of porous hydroxyapatite (HAp) bioceramics. HAp powders were synthesized by modified precipitation method using biogenic calcium carbonates (ostrich (Struthio camelus) egg shells, hen (Gallus gallus domesticus) egg shells, snail (Viviparus contectus) shells) and synthetic calcium oxides (Sigma-Aldrich and Fluka). Specific surface area, molecular structure and morphology of obtained powders were determined. As-synthesized HAp powders had a varied specific surface area with a wide range from 83 to 150 m2g-1 depending on CaO source. Porous bodies of HAp were prepared by in situ viscous mass foaming with NH4HCO3 as pore forming agent. Foamed and dried green bodies were sintered at 1100 °C. The obtained bioceramics were investigated using Archimedes method, field emission scanning electron microscopy and Brunauer-Emmett-Teller method. There are considerable differences between porous HAp bioceramics structures prepared from different sources of CaO. The choice of starting material substantially affects the macro-and microstructure of prepared porous bioceramics.

Preparation and Piezoelectric Catalytic Performance of Flexible Inorganic Ba1-xCaxTiO3 via Electrospinning

2021 ◽  
Author(s):  
Yang Yu ◽  
Xiao-Xiong Wang ◽  
Guixu Xie ◽  
Junqing Ma ◽  
Tianyang Lv ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Catalytic Reaction ◽  
Catalytic Performance ◽  
Research Field

Piezoelectric catalysis is an emerging research field in recent years. Since the catalytic reaction usually occurs on the surface, the specific surface area is very important for piezoelectric catalysis. Therefore,...

scholarly journals Structure-Activity Relationship of Manganese Oxide Catalysts for the Catalytic Oxidation of (chloro)-VOCs

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 726 ◽  
Author(s):  
Jian Wang ◽  
Hainan Zhao ◽  
Jianfei Song ◽  
Tingyu Zhu ◽  
Wenqing Xu
Keyword(s):  
Specific Surface ◽  
Manganese Oxide ◽  
Surface Area ◽  
Calcination Temperature ◽  
Specific Surface Area ◽  
Oxide Catalysts ◽  
Precipitation Method ◽  
Catalytic Oxidations ◽  
Calcination Temperatures ◽  
Manganese Oxide Catalysts

Manganese oxide catalysts, including γ-MnO2, Mn2O3 and Mn3O4, were synthesized by a precipitation method using different precipitants and calcination temperatures. The catalytic oxidations of benzene and 1,2-dichloroethane (1,2-DCE) were then carried out. The effects of the calcination temperature on the catalyst morphology and activity were investigated. It was found that the specific surface area and reducibility of the catalysts decreased with the increase in the calcination temperature, and both the γ-MnO2 and Mn3O4 were converted to Mn2O3. These catalysts showed good activity and selectivity for the benzene and 1,2-DCE oxidation. The γ-MnO2 exhibited the highest activity, followed by the Mn2O3 and Mn3O4. The high activity could be associated with the large specific surface area, abundant surface oxygen species and excellent low-temperature reducibility. Additionally, the catalysts were inevitably chlorinated during the 1,2-DCE oxidation, and a decrease in the catalytic activity was observed. It suggested that a higher reaction temperature could facilitate the removal of the chlorine species. However, the reduction of the catalytic reaction interface was irreversible.

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