Synergistic Degradation of Acid Scarlet Dyeing Wastewater by the Ultrasound/Fenton Method

2013 ◽  
Vol 448-453 ◽  
pp. 34-37
Author(s):  
Tong Liu ◽  
Feng Wei He ◽  
Ya Qin Zhang
Keyword(s):  
Degradation Rate ◽  
Low Ph ◽  
Mass Ratio ◽  
Dyeing Wastewater ◽  
Fenton Reagent ◽  
Initial Concentration ◽  
A Value ◽  
Ultrasonic Technology ◽  
Initial Ph ◽  
Synergistic Degradation

Degradation of simulated acid scarlet (GR) wastewater by ultrasonic technology , Fenton reagentoxidation , and a combination of the two processes was studied. It was found that extent of degradation by ultrasonic technology or Fenton reagent oxidation alone was poor , with values of 4 % and 40 % respectively. The extent of degradation was significantly enhanced when the two processes were combined , with a value of up to 90 % , which shows that these two processes have a good synergistic effect and can shorten the reaction time.Also discussed the initial concentration, initial pH, Fe2+ and H2O2 dosage and other factors on the degradation of acid scarlet. The results show that the degradation rate of pH significant effect on the low pH is conducive to degradation. Degradation rate with the dosage of H2O2 and FeSO4 temperature increased, but when acid scarlet with H2O2 and Fe2+ the mass ratio of 100:15:41, the degradation rate reached 96.6%.

Synergetic Degradation of Zidovudine Wastewater by Ultrasonic and Iron-Carbon Micro-Electrolysis

2011 ◽  
Vol 347-353 ◽  
pp. 1949-1952 ◽  
Author(s):  
Liang Li ◽  
Bing Zhe Xu ◽  
Chang Yu Lin ◽  
Xiao Min Hu
Keyword(s):  
Reaction Time ◽  
Degradation Rate ◽  
Removal Rate ◽  
Cod Removal ◽  
Mass Ratio ◽  
Initial Ph ◽  
Cod Removal Rate

Zidovudine wastewater is difficult to biodegradation due to high COD and toxicity. The synergetic treatment of Zidovudine wastewater by Ultrasonic and iron-carbon micro-electrolysis technology was studied. The influence of initial pH, reaction time, mass ratio of iron and carbon and mass ratio of iron and water on degradation rate of COD was researched. The result showed that the COD removal rate was only about 54.3% and the degradation speed is very slow when iron-carbon micro-electrolysis treated Zidovudine wastewater　separately. However, when ultrasonic synergy micro-electrolysis to treat Zidovudine wastewater, the COD removal rate could was up to 85% and the reaction time was also decreased. Moreover, the BOD5 / COD rose from 0.15 to 0.35, which meant the wastewater became easily biodegradable.

Degradation of bromamine acid by nanoscale zero-valent iron (nZVI) supported on sepiolite

2012 ◽  
Vol 66 (12) ◽  
pp. 2539-2545 ◽  
Author(s):  
Xuening Fei ◽  
Lingyun Cao ◽  
Lifeng Zhou ◽  
Yingchun Gu ◽  
Xiaoyang Wang
Keyword(s):  
Ph Value ◽  
Energy Dispersive Spectrometer ◽  
Zero Valent Iron ◽  
Mass Ratio ◽  
Initial Concentration ◽  
Preparation Conditions ◽  
Transmission Electron ◽  
Nanoscale Zero Valent Iron ◽  
Initial Ph ◽  
Set Up

Sepiolite, a natural nano-material, was chosen as a carrier to prepare supported nanoscale zero-valent iron (nZVI). The effects of preparation conditions, including mass ratio of nZVI and activated sepiolite and preparation pH value, on properties of the supported nZVI were investigated. The results showed that the optimal mass ratio of nZVI and sepiolite was 1.12:1 and the optimal pH value was 7. The supported nZVI was characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and energy dispersive spectrometer (EDS), and furthermore an analogy model of the supported nZVI was set up. Compared with the nZVI itself, the supported nZVI was more stable in air and possessed better water dispersibility, which were beneficial for the degradation of bromamine acid aqueous solution. The degradation characteristics, such as effects of supported nZVI dosage, initial concentration and initial pH value of the solution on the decolorization efficiency were also investigated. The results showed that in an acidic environment the supported nZVI with a dosage of 2 g/L showed high activity in the degradation of bromamine acid with an initial concentration of 1,000 mg/L, and the degree of decolorization could reach up to 98%.

Photocatalytic Treatment of MO in Water with BiOBr Photocatalyst

2011 ◽  
Vol 694 ◽  
pp. 554-558 ◽  
Author(s):  
Xiao Xia Zhao ◽  
Yan Wang ◽  
Zhu Qing Shi ◽  
Cai Mei Fan
Keyword(s):  
Degradation Rate ◽  
Ph Value ◽  
Degradation Process ◽  
Xenon Lamp ◽  
Experimental Conditions ◽  
Initial Concentration ◽  
X Ray ◽  
Hydrolysis Method ◽  
Methylene Orange ◽  
Initial Ph

The BiOBr catalyst prepared by the hydrolysis method was investigated with the X-ray diffractometry(XRD) and scanning electron microscope (SEM). The results show that the catalyst was the tetragonal primitive crystal structure and composed of homogeneous particles of fine ferrite plates. At the same time, the photocatalytic activity of BiOBr catalyst was evaluated by methylene orange (MO) in aqueous solution illuminated by Xenon lamp, and the degradation process parameters, such as initial concentration of MO, initial pH value and amount of BiOBr catalyst were discussed to the degradation rate of the MO. Under the following experimental conditions of C0=10mg/L, pH=8, m(BiOBr)=1.0g/L, MO can be entirely degraded after 2.5 hours.

Removal of Congo Red from Dyeing Wastewater by Biodegradation with Myriophyllum

2013 ◽  
Vol 671-674 ◽  
pp. 2742-2745
Author(s):  
Zheng Fan ◽  
Bo Sheng Lv ◽  
Ji Wei Zhang ◽  
Jin Zhe He ◽  
Guo Liang Zhang
Keyword(s):  
Great Reduction ◽  
Congo Red ◽  
Azo Dye ◽  
Degradation Rate ◽  
Environmental Benefits ◽  
Dyeing Wastewater ◽  
Congo Red Dye ◽  
Secondary Pollution ◽  
Initial Ph ◽  
Red Dye

In this study, Myriophyllum was used to remove Congo Red dye from wastewater. The influence of operation factors include illumination intensity, initial pH, biomass and dye concentration on the degradation rate of Congo Red were investigated. The experimental results demonstrated that Myriophyllum can effectively degradate Congo red dye. The Congo red dye was almost completely discolored in 10 days under the conditions of 5000 lx of illumination density, 7.5 of pH, 15g /L~17.5 g/L of initial biomass and less than 20 mg/L of Congo red concentration. Furthermore, the great reduction of intermediate products and COD indicated that biodegradation of Congo red dye with Myriophyllum not only produced less secondary pollution, but also mineralized azo dye into inorganic matters. Myriophyllum in pollutants degradation presented obvious technical advantages and environmental benefits.

Chemical Synthesis and Characterization of Carbon Supported Palladium Electro-Catalysts

2017 ◽  
Vol 16 (05n06) ◽  
pp. 1750007
Author(s):  
J. J. Acosta ◽  
P. C. Favilla ◽  
J. R. Collet-Lacoste
Keyword(s):  
Structure Type ◽  
X Ray Diffraction ◽  
Initial Concentration ◽  
Type Formula ◽  
A Value ◽  
Transmission Electron ◽  
Initial Ph ◽  
Modified Polyol Method

The aim of this work is to present the results obtained for the synthesis of Pd NPs by the modified-polyol method with Vulcan XC-72R as support. Two different ways were used to synthesize catalysts: (a) Maintaining the initial pH of the synthesis equal to 12 and changing the initial concentration of the precursor to obtain an overall 10 wt.% nominal Pd load; (b) Fixing the initial concentration of the precursor at 2[Formula: see text]mM whilst changing the initial pH of the synthesis at different values to obtain an overall 10[Formula: see text]wt.% nominal Pd load. Catalysts were characterized using X-ray diffraction (XRD), Transmission electron microscopy (HRTEM, TEM, STEM) and cyclic voltammetry (CV). This work shows that the density of NPs generated during the nucleation process is a consequence of the fluctuation of the concentration. The standard deviation of the diameters varied linearly with the mean volume for values between 0.5[Formula: see text]mM and 6[Formula: see text]mM, demonstrating that there was a clear separation between nucleation and growth processes. The final mean diameter strongly depends on the initial pH of the synthesis for the same initial concentration of the precursor; mean diameters are smaller for basic media. The analysis of the voltammograms allowed the determination of the coverage fraction of oxygen on Pd, obtaining a value of 0.51 with a structure type [Formula: see text]. The coverage value found for CO is 0.71 with a structure type [Formula: see text]CO.

Photo-catalytic degradation of gaseous pollutants in paper mills of southern China

TAPPI Journal ◽  
2018 ◽  
Vol 17 (03) ◽  
pp. 167-178 ◽  
Author(s):  
Xin Tong ◽  
Jiao Li ◽  
Jun Ma ◽  
Xiaoquan Chen ◽  
Wenhao Shen
Keyword(s):  
Degradation Rate ◽  
Southern China ◽  
Catalytic Degradation ◽  
Pulp And Paper ◽  
Gaseous Pollutants ◽  
Pulp And Paper Mills ◽  
Paper Mills ◽  
Initial Concentration ◽  
First Order ◽  
First Order Kinetics

Studies were undertaken to evaluate gaseous pollutants in workplace air within pulp and paper mills and to consider the effectiveness of photo-catalytic treatment of this air. Ambient air at 30 sampling sites in five pulp and paper mills of southern China were sampled and analyzed. The results revealed that formaldehyde and various benzene-based molecules were the main gaseous pollutants at these five mills. A photo-catalytic reactor system with titanium dioxide (TiO2) was developed and evaluated for degradation of formaldehyde, benzene and their mixtures. The experimental results demonstrated that both formaldehyde and benzene in their pure forms could be completely photo-catalytic degraded, though the degradation of benzene was much more difficult than that for formaldehyde. Study of the photo-catalytic degradation kinetics revealed that the degradation rate of formaldehyde increased with initial concentration fitting a first-order kinetics reaction. In contrast, the degradation rate of benzene had no relationship with initial concentration and degradation did not conform to first-order kinetics. The photo-catalytic degradation of formaldehyde-benzene mixtures indicated that formaldehyde behaved differently than when treated in its pure form. The degradation time was two times longer and the kinetics did not reflect a first-order reaction. The degradation of benzene was similar in both pure form and when mixed with formaldehyde.

Chitosan-based Magnetic Composites - Efficient Adsorbents for Removal of Pb(II) and Cu(II) from Aqueous Mono and Bicomponent Solutions

2018 ◽  
Vol 69 (9) ◽  
pp. 2323-2330 ◽  
Author(s):  
Daniela C. Culita ◽  
Claudia Maria Simonescu ◽  
Rodica Elena Patescu ◽  
Nicolae Stanica
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Chemical Properties ◽  
Order Kinetic ◽  
Mass Ratio ◽  
Magnetic Adsorbent ◽  
Magnetic Composites ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Physical And Chemical

A series of three chitosan-based magnetic composites was prepared through a simple coprecipitation method. It was investigated the influence of mass ratio between chitosan and magnetite on the physical and chemical properties of the composites in order to establish the optimum conditions for obtaining a composite with good adsorption capacity for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions. It was found that the microspheres prepared using mass ratio chitosan / magnetite 1.25/1, having a saturation magnetization of 15 emu g--1, are the best to be used as adsorbent for the metal ions. The influence of different parameters such as initial pH values, contact time, initial concentration of metal ions, on the adsorption of Pb(II) and Cu(II) onto the chitosan-based magnetic adsorbent was investigated in details. The adsorption process fits the pseudo-second-order kinetic model in both mono and bicomponent systems, and the maximum adsorption capacities calculated on the basis of the Langmuir model were 79.4 mg g--1 for Pb(II) and 48.5 mg g--1 for Cu(II) in monocomponent systems, while in bicomponent systems were 88.3 and 49.5 mg g--1, respectively. The results revealed that the as prepared chitosan-based magnetic adsorbent can be an effective and promising adsorbent for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions.

The stability of onoratoite, Sb8O11Cl2, in the supergene environment

2014 ◽  
Vol 78 (7) ◽  
pp. 1671-1675 ◽  
Author(s):  
Adam J. Roper ◽  
Peter Leverett ◽  
Timothy D. Murphy ◽  
Peter A. Williams
Keyword(s):  
Significant Influence ◽  
Secondary Phase ◽  
Low Ph ◽  
Stable Phase ◽  
Supergene Zone ◽  
A Value ◽  
Solubility Studies ◽  
The Stability ◽  
Very High

AbstractSynthesis and solubility studies of onoratoite have been undertaken to determine the role of this rare secondary phase in the immobilization of Sb and the conditions responsible for its formation in the supergene zone. Solubility studies were undertaken at 298.15 K. A value of ΔGfθ (Sb8O11Cl2, s, 298.15 K) = –2576 ±12 kJ mol–1 was derived. Calculations involving sénarmontite, Sb2O3, klebelsbergite, Sb4O4SO4(OH)2 and schafarzikite, FeSb2O4, show that onoratoite is a thermodynamically stable phase only at negligible activities of SO42–(aq) and low activities of Fe2+(aq), at low pH and very high activities of Cl–(aq). This explains why onoratoite is such a rare secondary phase and why it cannot exert any significant influence on the dispersion of Sb in the supergene environment.

scholarly journals Degradation of methylene blue by natural manganese oxides: kinetics and transformation products

2019 ◽  
Vol 6 (7) ◽  
pp. 190351 ◽  
Author(s):  
Shuangxi Zhou ◽  
Zhiling Du ◽  
Xiuwen Li ◽  
Yunhai Zhang ◽  
Yide He ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Manganese Oxides ◽  
Ph Value ◽  
Low Cost ◽  
Reaction System ◽  
Transformation Products ◽  
Low Ph ◽  
Initial Concentration ◽  
Environmental Material ◽  
High Redox Potential

In this study, natural manganese oxides (MnO x ), an environmental material with high redox potential, were used as a promising low-cost oxidant to degrade the widely used dyestuff methylene blue (MB) in aqueous solution. Although the surface area of MnO x was only 7.17 m 2 g −1 , it performed well in the degradation of MB with a removal percentage of 85.6% at pH 4. It was found that MB was chemically degraded in a low-pH reaction system and the degradation efficiency correlated negatively with the pH value (4–8) and initial concentration of MB (10–50 mg l −1 ), but positively with the dosage of MnO x (1–5 g l −1 ). The degradation of MB fitted well with the second-order kinetics. Mathematical models were also built for the correlation of the kinetic constants with the pH value, the initial concentration of MB and the dosage of MnO x . Furthermore, several transformation products of MB were identified with HPLC-MS, which was linked with the bond energy theory to reveal that the degradation was initiated with demethylation.

scholarly journals Treatment of simulated printing and dyeing wastewater using ozone microbubble

2021 ◽  
Vol 261 ◽  
pp. 04005
Author(s):  
Emmanuel Nkudede ◽  
Husseini Sulemana ◽  
Bo Zhang ◽  
Kaida Zhu ◽  
Shan Hu ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Methylene Blue ◽  
Removal Efficiency ◽  
Human Life ◽  
Cod Removal ◽  
Dyeing Wastewater ◽  
Flow Rates ◽  
Printing And Dyeing Wastewater ◽  
Cod Removal Efficiency ◽  
Initial Ph

Owing to its widespread and persistent usage, methylene blue (MB) is an environmental substance, mostly found in the printing and dyeing industry that raises concerns in the environment recently by posing significant threat to human life and the ecosystem as a whole. Thus, there is the need to effectively manage and treat the wastewater from these industries before reaching to the available water sources. Ozonation treatment is very efficient in treating printing and dyeing wastewater (MB) and can be greatly improved by using micro-bubble technology. Microbubble dissolution is an effective way to improve the rate of ozone mass transfer. To discover these properties, a method was used to improve the mass transfer of ozone microbubbles, which was used to effectively treat simulated printing and dyeing wastewater. We investigated the effects of pH, water temperature, ozone flow, and other conditions on the dissolution and attenuation properties of ozone in methylene blue microbubble solutions. Treatment of simulated printing and dyeing wastewater (methylene blue) was investigated under various initial pH and ozone flow rates. A catalytic exhibition was performed towards the decolorization of methylene blue (MB) concentrations and the corresponding COD removal efficiency. Ozone depletion and pH levels played key roles in MB degradation. Under high pH level of 11.01, the rate of removal of COD was 93.5%. Ozone dosage also has direct effect on COD removal efficiency and decolorization. Higher ozone flow rates, 0.4 L/min and 0.5 L/min recorded more than 94% degradation of COD thus very effective and efficient. Also, ozone flow rates 0.3 L/min, 0.4 L/min and 0.5 L/min with initial pH, 7.03, 6.63 and 6.36 decreased to 3.43, 3.49 and 3.44 after reaction processes which clearly shows that with high ozone dosage, pH reduces considerably.

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