scholarly journals Removal of Organic Dyes by Nanostructure ZnO-Bamboo Charcoal Composites with Photocatalysis Function

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Xinliang Yu ◽  
Aimiao Qin ◽  
Lei Liao ◽  
Rui Du ◽  
Ning Tian ◽  
...  
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
Ph Value ◽  
Organic Dyes ◽  
Irradiation Time ◽  
Removal Rate ◽  
Precipitation Method ◽  
Bamboo Charcoal ◽  
Acid Fuchsin ◽  
Removal Capacity

Composites of nanostructure zinc oxide (nano-ZnO) and bamboo charcoal (BC) were successfully prepared via impregnation-precipitation method. The products were characterized by XRD, SEM, and EDS. Rhodamine B (RhB) and acid fuchsin (AF) were selected as the organic dyes of photocatalysis degradation under the irradiation of ultraviolet light (UV). The influence of particle size of BC, irradiation time, pH value of the solution, and additive amount of H2O2on removal of the dyes has been studied. The results show that smaller particle size of BC in the composites has a better removal effect. The composites possess the highest removal capacity for RhB and AF under the conditions of pH = 2 and pH = 5.4, respectively. The optimum additive amount of H2O2for 5 mL RhB and AF was 0.050 mL and 0.1 mL, with a removal rate of 93% and 99%, respectively.

Process Study on Green Treatment of Waste Anolyte

2014 ◽  
Vol 1015 ◽  
pp. 350-354
Author(s):  
Li Na Chen ◽  
Wan Yi Liu ◽  
Qi Lin Hu
Keyword(s):  
Ph Value ◽  
Removal Rate ◽  
Chemical Precipitation ◽  
Environmental Benefits ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Dihydrogen Phosphate ◽  
Waste Solution ◽  
Hydrogen Carbonate ◽  
Ammonium Hydrogen

Contraposing the waste anolyte of industry, the paper proposed a new chemical precipitation method to recover Mn (II) ions and Mg (II) ions from the waste solution using ammonium hydrogen carbonate and ammonium dihydrogen phosphate as precipitants, respectively. The technological conditions of dealing procedure such as the molar ratio of reactants, pH value, reaction temperature and time, aging time were investigated. The results shown that the removal rate of Mn (II) ions and Mg (II) ions reached to 96 % and 98 %, and the yields of MnCO3 and NH4MgPO4·6H2O reached to 91 % and 94 %, respectively. The residual solution was recycled to realize the treatment greenly, which could meet the needs of production and increase environmental benefits.

scholarly journals Facile synthesis of a high purity α-MnO2 nanorod for rapid degradation of Rhodamine B

2021 ◽  
Author(s):  
shumin wang ◽  
Ao Guan ◽  
Jiahan Wang ◽  
Xiaofang Fu ◽  
Xiang Guo ◽  
...  
Keyword(s):  
Rhodamine B ◽  
High Efficiency ◽  
Catalytic Mechanism ◽  
Ph Value ◽  
Removal Rate ◽  
Precipitation Method ◽  
Characteristic Peak ◽  
Catalytic Stability ◽  
Rapid Removal ◽  
Co Precipitation

Abstract Manganese dioxide (α-MnO2) nanorods with diameters of about 5-15 nm and lengths of 100-150 nm were synthesized by a simple co-precipitation method. XRD, TEM, HRTEM, SAED and XPS were used to analyze the crystallographic information, microstructure and chemical bonding of the as-prepared sample. The α-MnO2 nanorod exhibited a high efficiency and rapid removal rate of rhodamine B (RhB), which reached about 97.5% within 10 min when pH=4 (and pH=6.6) and 97.7% within 50 min when pH = 9 in the presence of H2O2. The results also indicated that a lower pH value is conducive to the movement of the characteristic peak and the attenuation of the intensity of the characteristic peak of RhB dye. Then a possible catalytic mechanism was revealed. Moreover, the α-MnO2 nanorod exhibits an excellent recyclability and catalytic stability. This research indicates that α-MnO2 nanorods have a potential application in practical dye pollutant treatment.

Experimental Research on Mercury-Containing Wastewater in PVC Production by Fly Ash Processing Calcium Carbide Method

2014 ◽  
Vol 878 ◽  
pp. 578-584 ◽  
Author(s):  
Yan Li ◽  
Ping Sun
Keyword(s):  
Fly Ash ◽  
Ph Value ◽  
Removal Rate ◽  
Operating Cost ◽  
Calcium Carbide ◽  
Emission Standard ◽  
Removal Capacity ◽  
Positive Treatment ◽  
The Government ◽  
Modified Fly Ash

To study the removal capacity of modified fly ash in wastewater containing mercury ions under different conditions, the dust from a calcium carbide furnace was added to fly ash, and the pyrogenic process was employed to modify the fly ash. The result indicated that the wastewater had a pH value of 9, the modified fly ash dosage was 0.2 g, the adsorption equilibrium time was 40 minutes, the reaction temperature was 30 °C, and the removal rate could reach 91.9%. Using modified fly ash in polyvinyl chloride production via the calcium carbide method to remove mercury-containing wastewater can help meet the government-prescribed emission standard. This method has advantages such as positive treatment effect, simple operation, and low operating cost.

Synthesis of Spherical Zinc Oxide Micro-Flower via an Electric Field-Assisted Homogeneous Precipitation Method

2011 ◽  
Vol 328-330 ◽  
pp. 1541-1544 ◽  
Author(s):  
Xiu Juan Liang ◽  
Xiao Fang Hu ◽  
Xing Xing Weng ◽  
Da Wei Hu ◽  
Hai Xu Ji
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Zinc Oxide ◽  
Electric Field ◽  
Precipitation Method ◽  
Homogeneous Precipitation ◽  
Homogeneous Precipitation Method ◽  
Ft Ir ◽  
Particle Size And Morphology ◽  
Size And Morphology

This paper presents the experimental results on electric field-assisted synthesis of spherical Zinc Oxide (ZnO) micro-flower in an homogeneous precipitation method. The synthesis processes with and without an electric field were compared. The products were characterized via SEM, XRD, TGA and FT-IR spectrum. The results show that the spherical ZnO micro-flower composed of ZnO single crystalline nanoparticles have thickness of about 10nm, width of about 50nm.The SEM results show that the application of an electric field caused the morphology transformation from flake-like to flower-like. It was found that an electric field had an effect on the crystal structure,the particle size and morphology.

scholarly journals Excellent UV-Light Triggered Photocatalytic Performance of ZnO.SiO2 Nanocomposite for Water Pollutant Compound Methyl Orange Dye

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2548
Author(s):  
Sunil Rohilla ◽  
Ankita Gupta ◽  
Vibhor Kumar ◽  
Suman Kumari ◽  
Michal Petru ◽  
...  
Keyword(s):  
Methyl Orange ◽  
Ph Value ◽  
Uv Light ◽  
Irradiation Time ◽  
Diffraction Method ◽  
Hexagonal Structure ◽  
Precipitation Method ◽  
Photo Degradation ◽  
Systematic Analysis ◽  
Degradation Ability

The photocatalytic activity of eco-friendly zinc oxide doped silica nanocomposites, synthesized via a co-precipitation method followed by heat-treatment at 300, 600, and 900 °C is investigated. The samples have been characterized by employing X-ray diffraction method, and further analyzed using the Rietveld Refinement method. The samples show a space group P63mc with hexagonal structure. The prepared composites are tested for their photocatalytic activities for the degradation of methyl orange-based water pollutants under ultra-violet (UV) irradiation using a 125 W mercury lamp. A systematic analysis of parameters such as the irradiation time, pH value, annealing temperatures, and the concentration of sodium hydroxide impacting the degradation of the methyl orange (MO) is carried out using UV-visible spectroscopy. The ZnO.SiO2 nanocomposite annealed at 300 °C at a pH value of seven shows a maximum photo-degradation ability (~98.1%) towards methyl orange, while the photo-degradation ability of ZnO.SiO2 nanocomposites decreases with annealing temperature (i.e., for 600 and 900 °C) due to the aspect ratio. Moreover, it is seen that with increment in the concentration of the NaOH (i.e., from 1 to 3 g), the photo-degradation of the dye component is enhanced from 20.9 to 53.8%, whereas a reverse trend of degradation ability is observed for higher concentrations.

scholarly journals Effect of Particle Size and pH Value of Slurry on Chemical Mechanical Polishing of SiO2 Film

2022 ◽  
Author(s):  
Fan Xu ◽  
Weilei Wang ◽  
Aoxue Xu ◽  
Daohuan Feng ◽  
Weili Liu ◽  
...  
Keyword(s):  
Activation Energy ◽  
Particle Size ◽  
Chemical Mechanical Polishing ◽  
Ph Value ◽  
Removal Rate ◽  
Mechanical Action ◽  
Sio2 Film ◽  
Mechanical Polishing ◽  
Chemical Action ◽  
Effect Of Particle Size

Abstract This study investigated the effects of particle size and pH of SiO2-based slurry on chemical mechanical polishing for SiO2 film. It was found that the removal rates and surface roughness of the material was highly dependent on the particle size and pH. As the particle size varied, the main polishing mechanism provided the activation energy to mechanical erasure. In addition, pH affected the particle size and Zeta potential, which had an important effect on the strength of the mechanical and chemical action of the chemical mechanical polishing. The change in mechanical action greatly influenced the removal rate. According to the experimental results, the best polishing of SiO2 film was achieved with 40 nm particle size SiO2 abrasives when the pH was 4.

Experimental Research on Mercury-Containing Wastewater by Fly Ash

2013 ◽  
Vol 456 ◽  
pp. 559-563 ◽  
Author(s):  
Yan Li ◽  
Ping Sun
Keyword(s):  
Fly Ash ◽  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Ph Value ◽  
Removal Rate ◽  
Practical Application ◽  
Mercury Ions ◽  
Removal Capacity ◽  
Carbide Slag ◽  
Modified Fly Ash

To study the removal capacity of modified fly ash in wastewater containing mercury ions under different conditions, the carbide slag was added to fly ash, and the pyrogenic process was employed to modify the fly ash. The result indicated that the wastewater had a pH value of 11, the modified fly ash dosage was 2.0 g, the adsorption equilibrium time was 40 minutes, the reaction temperature was 30 °C, the removal rate could reach 97.1%, and the Freundlich-type adsorption isotherm can be used to simulate the adsorption process effectively. The modified fly ash can be used in the removal of mercury-containing wastewater, the overall result of the experiment is satisfactory, which indicates that the modified fly ash has potential value for practical application.

Photocatalytic Degradation of Diesel Pollutants in Seawater by Using Nano Li-Doped Zinc Oxide under Visible Light

2014 ◽  
Vol 609-610 ◽  
pp. 317-323
Author(s):  
Xiao Cai Yu ◽  
Dong Dong Hu ◽  
Jin Fang Chen ◽  
Yu Ying Wu ◽  
Xu Zheng
Keyword(s):  
Zinc Oxide ◽  
Reaction Time ◽  
Visible Light ◽  
Calcination Temperature ◽  
Ph Value ◽  
Removal Rate ◽  
Orthogonal Experiment ◽  
Initial Concentration ◽  
Five Factors ◽  
Doped Zno

Zinc Oxide (ZnO) is a potential semiconductor as photocatalyst. Nevertheless, its main absorbance wavelength is in the range of UV light, which consist only a small proportion of solar. In order to utilizing the large proportion of solar light, pure ZnO and Li-doped ZnO nanoparticles with different Li loading (1.0, 2.0, 3.0 and 4.0 at%) and various calcination temperature (300, 500, 700, 900°C) were synthesized through a co-precipitation method and characterized by XRD and TEM techniques. The photocatalytic abilities of photocatalysts are evaluated in simulated experiments of removing diesel pollutants in seawater under visible illumination. Six factors, Li loadings, calcination temperature, dosage of photocatalyst, reaction time, diesel initial concentration, and pH value of seawater, were taken into consideration in the process of phtotcatalytic degradation of diesel experiments under visible light. An orthogonal experiment was implemented to investigate the best combination of five factors (the factor of reaction time was excluded) which can lead to the highest diesel removal rate. The characterization of as-prepared nano-particles showed that Li element was doped into ZnO, and all particles were of hexagonal wurtzite structure. The average crystal sizes of Li-doped ZnO with various calcination temperature (300, 500, 700 and 900°C) are 15.03, 25.97, 48.63 and 55.48nm, respectively, and consequently, higher calcination temperature will contribute to the aggregation of particles. Doping Li appropriately can improve the photocatalystic ability of ZnO under visible light, which can deduce from the single-factor experiments. Calcination temperature is also an evident factor to affect the photocatalytic ability of photocatalyst. The influence order of factors in decreasing order can also be obtain through the orthogonal experiment and the result was as follows: calcination temperature > Li loading ≈ pH value > initial concentration of diesel > photocatalyst dosage. The best combination of the five factors is as follows, the dosage of catalyst 2.5g/L, initial concentration of diesel 1.5g/L, Li loading of catalyst 1.0 at%, calcinations temperature 900oC and pH value 8.25, the removal rate of diesel pollutants in seawater is expected to reach 77.31%.

Study on the Removal Effect of Chromium(VI) in Wastewater by Rice Husk

2014 ◽  
Vol 1073-1076 ◽  
pp. 825-828 ◽  
Author(s):  
Xue Min Dai ◽  
Shu Na Wang ◽  
Xia Wang
Keyword(s):  
Particle Size ◽  
Rice Husk ◽  
Ph Value ◽  
Removal Rate ◽  
Experimental Studies ◽  
Optimal Conditions ◽  
Solution Ph ◽  
Adsorption Time ◽  
Chromium Vi

Rice husk was used as an adsorbent to study the adsorption of Cr (VI) from wastewater, Based on the experimental studies on influences of the particle size of rice husk, solution pH value, adsorption time, temperature and rice husk dose, the optimal conditions of the adsorption were determined as follows: temperature of 35°C, pH of 2, the particle size of rice husk in the range of 80-100 mesh, adsorption time of 3h, dose of 30g/0.2g. Under the optimal conditions, the removal rate of chromium from wastewater by rice husk can reach 91%.

Study on Factors Affecting Properties of Silica

2011 ◽  
Vol 233-235 ◽  
pp. 332-336
Author(s):  
Quan Xiao Liu ◽  
Wen Cai Xu ◽  
Yu Bin Lv ◽  
Jin Li Li
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Ph Value ◽  
Precipitation Method ◽  
Drying Methods ◽  
Drying Process ◽  
Factors Affecting ◽  
Base Solution

Silica was prepared by precipitation method in the laboratory, and the factors which affect the performance of silica were evaluated. The results show that the reduction of concentration of base solution and reaction temperature and the increase of pH value could improve the specific surface area of precipitation silica. Specific surface area of silica prepared in laboratory is greater than which was prepared in production line and DBP absorption value and particle size are smaller than the latter. Drying process and drying methods have important influences on performance of precipitation silica. Mechanical pulverization could reduce the particle size of silica slightly and the stacking density obviously.

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