Limitations of the removal of cyanide from coking wastewater by ozonation and by the hydrogen peroxide-ozone process

2016 ◽  
Vol 74 (2) ◽  
pp. 482-490 ◽  
Author(s):  
N. Pueyo ◽  
N. Miguel ◽  
J. L. Ovelleiro ◽  
M. P. Ormad
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Removal Efficiency ◽  
Industrial Wastewater ◽  
Molar Ratio ◽  
Coking Wastewater ◽  
Organic Micropollutants ◽  
Mass Ratio ◽  
Bicarbonate Ions ◽  
Cyanide Removal

The purpose of this study is to compare the efficiency of ozonation and the hydrogen peroxide–ozone process for the removal of cyanide from coking wastewater. The most efficient oxidation process is combined with coagulation–flocculation–decantation and lime–soda ash softening pretreatments. The oxidation in aqueous solution and industrial wastewater (at pH 9.5–12.3) by O3 was carried out using a range of concentration of consumed O3 from 10 to 290 mg/L. A molar ratio of H2O2/O3 from 0.1 to 5.2 with different concentrations of O3 constants was used for the H2O2-O3 process. The maximum cyanide removal obtained in coking wastewater was 90% using a mass ratio of O3/CN– of 9.5. Using lower concentrations of O3, cyanide is not removed and can even be generated due to the presence of other cyanide precursor organic micropollutants in the industrial matrix. The concentration of O3 is reduced to half for the same cyanide removal efficiency if the pretreatments are applied to reduce the carbonate and bicarbonate ions. The cyanide removal efficiency in coking wastewater is not improved if the O3 is combined with the H2O2. However, the preliminary cyanide removal treatment in aqueous solution showed an increase in the cyanide removal efficiency for the H2O2-O3 process.

scholarly journals Removal of cyanide in aqueous solution by oxidation with hydrogen peroxide catalyzed by copper oxide

2019 ◽  
Vol 80 (1) ◽  
pp. 126-133
Author(s):  
Hamza Amaouche ◽  
Salima Chergui ◽  
Farid Halet ◽  
Ahmed Réda Yeddou ◽  
Abdelmalek Chergui ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Copper Oxide ◽  
Copper Oxide Nanoparticles ◽  
Catalyst Stability ◽  
Molar Ratio ◽  
First Order ◽  
Cyanide Removal ◽  
Stability Kinetics ◽  
Kinetics Of

Abstract This work is dedicated to the removal of free cyanide from aqueous solution through oxidation with hydrogen peroxide H2O2 catalyzed by copper oxide nanoparticles. Effects of initial molar ratio [H2O2]0/[CN−]0, catalyst dose, temperature, pH and the catalyst stability on cyanide removal have been investigated. The use of copper oxide has improved the reaction rate showing catalytic activity. The cyanide removal efficiency was increased from 60% to 94% by increasing in the dose of catalyst from 0.5 g/L to 5.0 g/L. Increasing the temperature from 20 °C to 35 °C promotes cyanide removal and the four successive times re-use of catalyst shows good stability. Kinetics of cyanide removal was found to be of pseudo-first-order with respect to cyanide. The rate constants have been determined.

Destruction of EDTA by Bimetallic Al-Fe/O2 Process under Aqueous Room Temperature and Pressure Conditions

2013 ◽  
Vol 800 ◽  
pp. 555-559
Author(s):  
Xin Liu ◽  
Jin Hong Fan ◽  
Lu Ming Ma
Keyword(s):  
Aqueous Solution ◽  
Benzoic Acid ◽  
Removal Efficiency ◽  
Room Temperature ◽  
Ethylenediaminetetraacetic Acid ◽  
Oxidative Degradation ◽  
Hydroxybenzoic Acid ◽  
Mass Ratio ◽  
Initial Ph ◽  
Temperature And Pressure

Oxidative degradation of ethylenediaminetetraacetic acid (EDTA) in aqueous solution at room temperature and pressure by the bimetallic Al-Fe/O2 process, which was verified by the addition of benzoic acid as ·OH scavenger and the detection of para-hydroxybenzoic acid, was investigated. The results showed that the removal efficiency of EDTA, TOC and TN could be about 98%, 77.5% and 43% respectively after 3h reaction when the initial pH was 5. The effects of initial pH, concentration of EDTA, mass ratio of Al0 and Fe0 and Al-Fe loading were also investigated. Significantly, the bimetallic Al-Fe process exhibited higher reactivity than monometallic Fe0/Al0 process for the degradation of EDTA when the mass ratio of Al0 and Fe0 ranged from 0.11 to 2.97.

scholarly journals A new treatment design for water contaminated with phenol

2019 ◽  
Vol 6 (3) ◽  
pp. 185-190
Author(s):  
Ali Abdul Rahman-Al Ezzi ◽  
Salam H. Alhamdiny
Keyword(s):  
Hydrogen Peroxide ◽  
Removal Efficiency ◽  
Organic Pollutants ◽  
Cost Effective ◽  
Synthetic Wastewater ◽  
Molar Ratio ◽  
Airflow Rate ◽  
Treatment Technique ◽  
Retention Period ◽  
Cost Effective Treatment

Background: Several important designs have been applied to remove toxic and hazardous organic substances like phenol and phenol compounds from wastewater, but there is a need to seek an alternative design to effectively remove organic pollutants from water to less hazardous compounds and a costeffective system. Methods: A modified internal loop airlift reactor was designed to remove the organic pollutants in synthetic wastewater using an efficient and cost-effective treatment technique by means of a synergistic effect of combination oxidation, stripping, and adsorption. The influence of the current style was experimentally examined in the treatment of synthetic phenol contaminated wastewater. The practical device was tested under different airflow rates range (2-15 L/min) through gross difference retention period (5-60 minutes) at a various molar ratio of phenol to hydrogen peroxide ranging from 1:10 to 1:20. Results: It was revealed that the preferred molar ratio of phenol to hydrogen peroxide equals to 1:20. Moreover, the airflow rate is 15 L/min with longer retention period of 60 minutes, indicating the maximum removal efficiency (89%) of phenol from the synthetic wastewater. Conclusion: Successful removal of phenol from water by the removal efficiency of 89% boosts the success of the executed design as well as the scenario of conducting the synergistic processes (stripping, oxidation and adsorption) in one device and also increases the chances of solving environmental problems via treating wastewater before recycling and releasing it into natural water sources.

Elimination of EDTA in Aqueous Solution by Bimetallic Al-Fe Process

2013 ◽  
Vol 726-731 ◽  
pp. 2398-2402
Author(s):  
Xin Liu ◽  
Jin Hong Fan ◽  
Lu Ming Ma
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Ethylenediaminetetraacetic Acid ◽  
Oxidative Degradation ◽  
The Novel ◽  
Mass Ratio ◽  
Initial Ph ◽  
Temperature And Pressure ◽  
Ph Concentration

Oxidative degradation of ethylenediaminetetraacetic acid(EDTA) in aqueous solution at normal temperature and pressure by the novel bimetallic Al-Fe was investigated. The results showed that the removal efficiency of EDTA, TOC and TN could be about 98%, 75% and 47% respectively after 3h reaction. The effects of initial pH, concentration of EDTA, mass ratio of Al0and Fe0and Al-Fe loading were also investigated. Significantly, the bimetallic Al-Fe process exhibited higher reactivity than monometallic Fe0/Al0process for the degradation of EDTA.

Research on Synthesis Regularity of Epoxysuccinic Acid

2013 ◽  
Vol 316-317 ◽  
pp. 942-945
Author(s):  
Qing He Gao ◽  
Yi Can Wang ◽  
Zhi Feng Hou ◽  
Hui Juan Qian ◽  
Yuan Zhang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Maleic Anhydride ◽  
Reaction Temperature ◽  
Raw Material ◽  
Molar Ratio ◽  
Mass Ratio ◽  
Synthesis System ◽  
Reaction Conditions ◽  
Sodium Hydrate

The yield of epoxysuccinic acid was obtained by determining the content of unreacted maleic anhydride and tartaric acid as a by-product in synthesis system. This method could calculate the yield of epoxysuccinic acid precisely and overcome the disadvantage of obtaining inpure product by recrystallization method. Epoxysuccinic Acid was synthesized using maleic anhydride as raw material, hydrogen peroxide as oxidizer and tungstate as catalyst. The effects of reaction temperature, reaction time, ratio of materials, dosage of oxidizer and catalyst on epoxidation and hydrolysis reaction was investigated. The results showed that the yield of epoxysuccinic acid was 88% when the reaction conditions were as follows: reaction temperature 65°C, reaction time 1.5h, catalyst dosage 3%(based on mass of maleic anhydride), molar ratio of sodium hydrate to maleic anhydride 2:1, mass ratio of hydrogen peroxide to maleic anhydride 1:1.

Role of peroxidase and chitosan in removing chlorophenols from aqueous solution

1996 ◽  
Vol 34 (10) ◽  
pp. 151-159 ◽  
Author(s):  
Hossein Ganjidoust ◽  
Kenji Tatsumi ◽  
Shinji Wada ◽  
Mitsuo Kawase
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Horseradish Peroxidase ◽  
Industrial Wastewater ◽  
Aluminum Sulfate ◽  
Enzymatic Reaction ◽  
Hexamethylene Diamine ◽  
Natural Coagulant

Chlorophenols removal from industrial wastewater by horseradish peroxidase and coagulant was investigated. It was found that an enzymatic reaction time of less than one hour was enough for the reaction to reach 95% completion. Chitosan, which is a natural coagulant, was an effective coagulant as compared to mineral coagulants such as aluminum sulfate (ALUM), hexamethylene diamine epichlorohydrin polycondensate (HX), polyacrylamide (PAM), and polyethyleneimine (PEI). A combination of 0.4 U/mL peroxidase to 2 ppm chitosan along with 0.8 mM of hydrogen peroxide resulted in over 95% chlorophenol removal from aqueous solution.

Study on the Removal of Copper Ions from Water Using Eco-Friendly Attapulgite/Chitosan Composites

2012 ◽  
Vol 499 ◽  
pp. 419-422
Author(s):  
Yong Chen ◽  
Hui Xu ◽  
Jin Bao Sun ◽  
Chang Long Zhang
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Room Temperature ◽  
Copper Ions ◽  
External Factors ◽  
Mass Ratio ◽  
Absorption Time ◽  
Adsorption Time ◽  
Initial Concentration ◽  
Adsorbent Dosage

In this work attapulgite and chitosan were employed to prepare composites as eco-friendly adsorbent. Study on the removal efficiency of the adsorbent for copper ions in aqueous solution was carried out. External factors such as the amount of attapulgite in the composites, temperature, initial concentration of copper ions, adsorption time and adsorbent dosage how to influence the removal efficiency of composites were investigated. The results showed that at room temperature, 0.37g adsorbent can reach maximum adsorption rate, which the mass ratio of attapulgite and chitosan is 1:1, the initial concentration of copper ions is 50mg / L and absorption time is 2h.

Control of Organic Micropollutants Using Dual Functional Adsorbent/Catalyst System

2007 ◽  
Vol 544-545 ◽  
pp. 35-38
Author(s):  
Jae Hyuk Kim ◽  
Se Jung Kim ◽  
Chung Hak Lee ◽  
Sang Ho Lee
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Oxidation Reaction ◽  
Catalyst Deactivation ◽  
Catalyst System ◽  
Organic Micropollutants ◽  
Dual Functional ◽  
Acidic Conditions ◽  
Molecular Catalysts ◽  
Catalytic Deactivation

This study focuses on the development of novel catalysts for simultaneous adsorption and oxidation of micropollutants in aqueous phase. Molecular catalysts were physically immobilized on the surface or pore of amberlite IRA-400 or powdered activated carbon (PAC). Comparison of different combinations of catalysts and adsorbents showed that the Fe(III)-TsPc combined with amberlite had the highest removal efficiency for target compounds. Although the catalyst was immobilized by electrical attraction, no dissociation of catalyst from adsorbent occurred during the tests. Amberlite-supported Fe(III)-TsPc shows more than 98% removal efficiency in 40 min. In homogenous system (suspension of Fe(III)-TsPc in aqueous solution), the oxidation reaction occurred only in acidic conditions (pH ~ 4.5) and the catalyst deactivation rate was fast. On the contrary, the reaction was fast in neutral pH and catalytic deactivation was negligible using the amberlite-supported Fe(III)-TsPc.

Comparative Bio-sorption of Cadmium and Nickel Ions from Aqueous Solution onto Fibers of Date Palm using Fluidized Bed Column

2019 ◽  
Vol 70 (5) ◽  
pp. 1507-1512
Author(s):  
Baker M. Abod ◽  
Ramy Mohamed Jebir Al-Alawy ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Metal Ions ◽  
Fluidized Bed ◽  
Removal Efficiency ◽  
Heavy Metal Ions ◽  
Date Palm ◽  
Operating Conditions ◽  
Initial Concentration ◽  
Bed Height

The aim of this study is to use the dry fibers of date palm as low-cost biosorbent for the removal of Cd(II), and Ni(II) ions from aqueous solution by fluidized bed column. The effects of many operating conditions such as superficial velocity, static bed height, and initial concentration on the removal efficiency of metal ions were investigated. FTIR analyses clarified that hydroxyl, amine and carboxyl groups could be very effective for bio-sorption of these heavy metal ions. SEM images showed that dry fibers of date palm have a high porosity and that metal ions can be trapped and sorbed into pores. The results show that a bed height of 6 cm, velocity of 1.1Umf and initial concentration for each heavy metal ions of 50 mg/L are most feasible and give high removal efficiency. The fluidized bed reactor was modeled using ideal plug flow and this model was solved numerically by utilizing the MATLAB software for fitting the measured breakthrough results. The breakthrough curves for metal ions gave the order of bio-sorption capacity as follow: Cd(II)]Ni(II).

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