scholarly journals Photocatalytic degradation of reactive black 5 on the surface of tin oxide microrods

2018 ◽  
Vol 16 (5) ◽  
pp. 773-781 ◽  
Author(s):  
Shanza Rauf Khan ◽  
Muhammad Umar Khalid ◽  
Saba Jamil ◽  
Songnan Li ◽  
Aiman Mujahid ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Tin Oxide ◽  
Degradation Kinetics ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Reactive Black 5 ◽  
Unit Cells ◽  
High Concentrations ◽  
Co Precipitation ◽  
Kinetics Of

Abstract A simple co-precipitation technique is proposed for synthesis of tin oxide (SnO2) microrods. Stannous chloride and urea were used during synthesis. X-ray powder diffraction (XRD) analysis revealed that the annealed product consists of SnO2 microrods having tetragonal unit cells, while scanning electron microscopy (SEM) analysis revealed the rod-like morphology of a synthesized product. These synthesized microrods are used as photocatalyst for the degradation of reactive black 5 (RB5). Degradation kinetics of RB5 are monitored under daylight in different concentrations of hydrogen peroxide (H2O2) and catalyst. The percentage of RB5 conversion is also calculated at various concentrations of hydrogen peroxide and catalyst which demonstrate that RB5 shows high catalytic degradation at high concentrations of hydrogen peroxide and catalyst.

Synthesis of Magnesia Powder from East Java Dolomite through Leaching, Precipitation and Calcination

2015 ◽  
Vol 1112 ◽  
pp. 550-554
Author(s):  
M. Zaki Mubarok ◽  
Christian Adi Kurniawan
Keyword(s):  
Particle Diameter ◽  
Acid Leaching ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Leach Solution ◽  
Water Removal ◽  
Solution Ph ◽  
Crystal Water ◽  
Lower Temperature ◽  
Co Precipitation

At the present paper, a process of magnesia (MgO) synthesis from East Java dolomite through hydrochloride acid leaching, precipitation and calcination as well as characteristic of the product is discussed. Results of the experimental works show that the dissolution rate of magnesium and calcium from dolomite in hydrochloride acid solution was very rapid. Complete magnesium extraction was obtained by the leaching test with acid concentration of 1.5 molar, particle size distribution of -325#, solid-liquid ratio 1:20 (g/mL), stirring speed 200 rpm at room temperature after only 10 seconds. Precipitation of Mg(OH)2 by the addition of 20% (v/v) CaO slurry into pregnant leach solution resulted in 97.5% Mg precipitation after 1 minute. Solution pH must be maintained at a level of 10-10.5 by adjusting CaO addition in order to minimize calcium co-precipitation and to obtain high purity of Mg(OH)2 precipitate. Calcinations of Mg(OH)2 were performed at temperature range of 550-800°C in which 99% of crystal water removal took place after 5 minute at temperature of 800°C. Lower temperature requires longer time of crystalline water removal from Mg(OH)2. XRF analysis showed MgO purity of 88% with the main impurities of calcium and chloride. XRD analysis detected the presences of calcium as calcite (CaCO3) and portlandite (Ca(OH)2) as impurities in the MgO product. SEM analysis of the MgO powder revealed a nano size of MgO with particle diameter of about 50 nm.

scholarly journals Influence of ZrO2 Nanoparticles on the Microstructural Development of Cement Mortars with Limestone Aggregates

2019 ◽  
Vol 9 (3) ◽  
pp. 598
Author(s):  
Danna Trejo-Arroyo ◽  
Karen Acosta ◽  
Julio Cruz ◽  
Ana Valenzuela-Muñiz ◽  
Ricardo Vega-Azamar ◽  
...  
Keyword(s):  
Xrd Analysis ◽  
Sem Analysis ◽  
Precipitation Method ◽  
Zro2 Nanoparticles ◽  
Microstructural Development ◽  
Cement Ratio ◽  
Cement Mortars ◽  
Crystallite Sizes ◽  
Co Precipitation ◽  
Two Stages

In this research, the effect of the addition of zirconium oxide-synthesized nanoparticles on the microstructural development and the physical–mechanical properties of cement mortars with limestone aggregates was studied. Zirconia nanoparticles were synthesized using the co-precipitation method. According to XRD analysis, a mixture of tetragonal (t) and monoclinic (m) zirconia phases was obtained, with average crystallite sizes around 15.18 and 17.79 nm, respectively. Based on the ASTM standards, a mixture design was obtained for a coating mortar with a final sand/cement ratio of 1:2.78 and a water/cement ratio of 0.58. Control mortars and mortars with ZrO2 additions were analyzed for two stages of curing of the mortar—7 and 28 days. According to SEM analysis, mortars with ZrO2 revealed a microstructure with a high compaction degree and an increase in compressive strength of 9% on the control mortars. Due to the aggregates’ characteristics, adherence with the cement paste in the interface zone was increased. It is suggested that the reinforcing effect of ZrO2 on the mortars was caused by the effect of nucleation sites in the main phase C–S–H and the inhibition of the growth of large CH crystals, and the filler effect generated by the nanometric size of the particles. This produced a greater compaction volume, suggesting that faults are probably originated in the aggregates.

scholarly journals Highly efficient UV/H2O2 technology for the removal of nifedipine antibiotics: Kinetics, co-existing anions and degradation pathways

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258483
Author(s):  
Wenping Dong ◽  
Chuanxi Yang ◽  
Lingli Zhang ◽  
Qiang Su ◽  
Xiaofeng Zou ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Degradation Rate ◽  
Degradation Kinetics ◽  
Degradation Pathways ◽  
Oxygen Species ◽  
Highly Efficient ◽  
Initial Ph ◽  
Primary Key ◽  
Kinetics Of

This study investigates the degradation of nifedipine (NIF) by using a novel and highly efficient ultraviolet light combined with hydrogen peroxide (UV/H2O2). The degradation rate and degradation kinetics of NIF first increased and then remained constant as the H2O2 dose increased, and the quasi-percolation threshold was an H2O2 dose of 0.378 mmol/L. An increase in the initial pH and divalent anions (SO42- and CO32-) resulted in a linear decrease of NIF (the R2 of the initial pH, SO42- and CO32- was 0.6884, 0.9939 and 0.8589, respectively). The effect of monovalent anions was complex; Cl- and NO3- had opposite effects: low Cl- or high NO3- promoted degradation, and high Cl- or low NO3- inhibited the degradation of NIF. The degradation rate and kinetics constant of NIF via UV/H2O2 were 99.94% and 1.45569 min-1, respectively, and the NIF concentration = 5 mg/L, pH = 7, the H2O2 dose = 0.52 mmol/L, T = 20 ℃ and the reaction time = 5 min. The ·OH was the primary key reactive oxygen species (ROS) and ·O2- was the secondary key ROS. There were 11 intermediate products (P345, P329, P329-2, P315, P301, P274, P271, P241, P200, P181 and P158) and 2 degradation pathways (dehydrogenation of NIF → P345 → P274 and dehydration of NIF → P329 → P315).

Spinel ferrites as catalysts: A study on catalytic effect of coprecipitated ferrites on hydrogen peroxide decomposition

1991 ◽  
Vol 69 (1) ◽  
pp. 33-36 ◽  
Author(s):  
Preeti Lahiri ◽  
Susanta K. Sengupta
Keyword(s):  
Hydrogen Peroxide ◽  
Compensation Effect ◽  
Activation Parameters ◽  
Neutral Medium ◽  
Specific Rate ◽  
Hydrogen Peroxide Decomposition ◽  
Peroxide Decomposition ◽  
Co Precipitation ◽  
Kinetics Of ◽  
Catalytic Power

Some ferrospinels act as catalysts for the decomposition of H2O2, their effectiveness is dependent on the composition of the catalyst. This study is to find the most effective catalyst of stoichiometry MIIFe2IIIO4. A set of ferrites of different composition MIIFe2II04 (MII = Mn, Co, Ni, Cu, Zn, Cd) was synthesized by co-precipitation and characterized by chemical analysis, X-ray diffractometry, and B.E.T. technique. A comparative assessment of the catalytic power of these ferrites from investigations of their influence on the kinetics of H2O2 decomposition in a neutral medium was made. An analysis of the data on specific rate, and the Eyrings activation parameters for the reaction sharply reveal the following: (a) The catalytic power follows the order MnFe2O4 > CoFe2O4 > CuFe2O4 > NiFe2O4 > CdFe2O4 > ZnFe2O4, MnFe2O4 is much more highly effective than the others (50–100 fold). (b) A compensation effect has been noted from the observed linearity with slightly less than unity slope between TΔ≠S0 and Δ≠H0 over the entire series. Key words: Ferrospinels, catalysis, hydrogen peroxide decomposition kinetics.

Kinetics of decolorization and mineralization of the azo dye Reactive Black 5 by hydrogen peroxide and UV light

2001 ◽  
Vol 44 (5) ◽  
pp. 295-301 ◽  
Author(s):  
A. Mohey El-Dein ◽  
J.A. Libra ◽  
U. Weismann
Keyword(s):  
Hydrogen Peroxide ◽  
Uv Light ◽  
Anaerobic Bacteria ◽  
White Rot Fungi ◽  
White Rot ◽  
Aerobic Biodegradation ◽  
Reactive Black 5 ◽  
Sulfate Reducing ◽  
Facultative Anaerobic Bacteria ◽  
Kinetics Of

C.I. Reactive Black 5 is one of the most used reactive dyes for textile finishing. It is a diazo dye, which can be decolorized by facultative anaerobic bacteria, sulfate reducing bacteria and aerobic white rot fungi. Mineralization by microorganisms has proven difficult. Advanced oxidation processes are promising alternatives for the decolorization and mineralization of Reactive Black 5, alone and in combination with aerobic biodegradation. The kinetics of the decolorization of Reactive Black 5 using a combination of hydrogen peroxide and UV radiation have been investigated. The rate of decolorization is first order with respect to dye concentration. It is enhanced with increasing hydrogen peroxide concentrations up to an optimum value. In our model we have correlated an empirical reaction rate expression which considers the contribution of both hydrogen peroxide and UV flux radiation based on the reaction kinetics. This empirical correlation agrees well with the experimental data for these conditions. Complete decolorization corresponded with 40-50% mineralization of the dye. Further mineralization can be achieved with extended radiation time.

Study of kinetics of degradation of cyclohexane carboxylic acid by acclimated activated sludge

2016 ◽  
Vol 73 (10) ◽  
pp. 2552-2558 ◽  
Author(s):  
Chunhua Wang ◽  
Shuian Shi ◽  
Hongyan Chen
Keyword(s):  
Carboxylic Acid ◽  
Activated Sludge ◽  
Degradation Kinetics ◽  
Experimental Conditions ◽  
First Order Kinetics ◽  
Effects Of Ph ◽  
High Concentrations ◽  
Cyclohexane Carboxylic Acid ◽  
Kinetics Of ◽  
Acclimated Activated Sludge

Activated sludge contains complex microorganisms, which are highly effective biodegrading agents. In this study, the kinetics of biodegradation of cyclohexane carboxylic acid (CHCA) by an acclimated aerobic activated sludge were investigated. The results showed that after 180 days of acclimation, the activated sludge could steadily degrade >90% of the CHCA in 120 h. The degradation of CHCA by the acclimated activated sludge could be modeled using a first-order kinetics equation. The equations for the degradation kinetics for different initial CHCA concentrations were also obtained. The kinetics constant, kd, decreased with an increase in the CHCA concentration, indicating that, at high concentrations, CHCA had an inhibiting effect on the microorganisms in the activated sludge. The effects of pH on the degradation kinetics of CHCA were also investigated. The results showed that a pH of 10 afforded the highest degradation rate, indicating that basic conditions significantly promoted the degradation of CHCA. Moreover, it was found that the degradation efficiency for CHCA increased with an increase in temperature and concentration of dissolved oxygen under the experimental conditions.

scholarly journals Biodegradation of Allethrin by a Novel Fungus Fusarium proliferatum Strain CF2, Isolated from Contaminated Soils

2020 ◽  
Vol 8 (4) ◽  
pp. 593 ◽  
Author(s):  
Pankaj Bhatt ◽  
Wenping Zhang ◽  
Ziqiu Lin ◽  
Shimei Pang ◽  
Yaohua Huang ◽  
...  
Keyword(s):  
Microbial Degradation ◽  
Contaminated Soils ◽  
Degradation Kinetics ◽  
Fusarium Proliferatum ◽  
Minimal Salt Medium ◽  
Optimum Conditions ◽  
Uninoculated Control ◽  
High Concentrations ◽  
Continuous Use ◽  
Kinetics Of

Continuous use of allethrin has resulted in heavy environmental contamination and has raised public concern about its impact on human health, yet little is known about the kinetics and microbial degradation of this pesticide. This study reported the degradation kinetics in a novel fungal strain, Fusarium proliferatum CF2, isolated from contaminated agricultural fields. Strain CF2 utilized 50 mg·L−1 of allethrin as the sole carbon source for growth in minimal salt medium and tolerated high concentrations of allethrin of up to 1000 mg·L−1. The optimum degradation conditions for strain CF2 were determined to be a temperature of 26 °C and pH 6.0 using response surface methodology. Under optimum conditions, strain CF2 completely degraded allethrin within 144 hours. The degradation kinetics of allethrin followed first order reaction kinetics. Kinetics analysis showed that its half-life was substantially reduced by 507.1 hours, as compared to the uninoculated control. This study provides new insights into the microbial degradation of allethrin with fungal F. proliferatum CF2.

Degradation Kinetics of Reactive Black 5 Wastewater by UV/H2O2

2013 ◽  
Vol 16 (2) ◽  
Author(s):  
Hang Xu ◽  
Airong Xu
Keyword(s):  
Degradation Kinetics ◽  
Degradation Process ◽  
Reactive Black 5 ◽  
Kinetics Of

AbstractDegradation process of Reactive Black 5 (RB 5) by UV/H

The synthesis of Ba2+-doped multiferroic BiFeO3 nanoparticles using co-precipitation method in the presence of various surfactants and the investigation of structural and magnetic features

2017 ◽  
Vol 31 (15) ◽  
pp. 1750169 ◽  
Author(s):  
Reza Mardani
Keyword(s):  
Magnetic Properties ◽  
Bismuth Ferrite ◽  
Sodium Dodecyl ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Precipitation Method ◽  
Ferrite Structure ◽  
Vibration Sample Magnetometry ◽  
Size Of Particles ◽  
Co Precipitation

In this paper, doped bismuth ferrite nanoparticles with barium (Bi[Formula: see text]Ba[Formula: see text]FeO[Formula: see text], [Formula: see text] = 0.1, 0.15, 0.2) were synthesized by co-precipitation method in the presence of various surface activators. Structural properties, magnetic properties and the size of synthesized nanoparticles were investigated by different techniques such as Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM), dynamic light scattering (DLS) and vibration sample magnetometry (VSM). The data obtained from XRD analysis showed a phase shift from rhombohedral to tetragonal structure by the enhancement of Barium amount in Bismuth ferrite structure. The results of TEM exhibit that the size of particles are 10 nm in average for the synthesized Bi[Formula: see text]Ba[Formula: see text]FeO[Formula: see text] and SEM analysis clarifies the uniform shape of particles which confirms the benign purity of the obtained material. VSM analysis shows that the best magnetic function will be observed when stoichiometric amount of Barium (Bi[Formula: see text]Ba[Formula: see text]FeO[Formula: see text] is [Formula: see text] = 0.15. The effect of diverse surface activators including Triton X-100, polyvinyl alcohol (PVA), sodium dodecyl sulfate (SDS), and cetyl trimethylammonium bromide (CTAB) was studied in the synthesis of Bi[Formula: see text]Ba[Formula: see text]FeO[Formula: see text] nanoparticles and CTAB presented the best effect on the magnetic properties of these nanoparticles.

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