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.

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.

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

2013 ◽  
Vol 779-780 ◽  
pp. 21-25
Author(s):  
Xin Liu ◽  
Jin Hong Fan ◽  
Lu Ming Ma
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Metal Pollution ◽  
Esr Spectroscopy ◽  
Ethylenediaminetetraacetic Acid ◽  
Degradation Products ◽  
Oxidative Degradation ◽  
Cu Content ◽  
Initial Ph ◽  
Temperature And Pressure

Oxidative degradation of ethylenediaminetetraacetic acid in aqueous solution at normal temperature and pressure by the bimetallic Fe-Cu, which was verified by ESR spectroscopy, was investigated. The results showed that the removal efficiency of EDTA, TOC and TN could be about 99%, 60% and 39% respectively after 3h reaction. The degradation products were iminodiacetate, formate and acetate. The effects of initial pH, concentration of EDTA, Cu content and Fe-Cu loading were also investigated. Significantly, the bimetallic Fe-Cu process exhibited higher reactivity than monometallic Fe0process for the degradation of EDTA and it would not cause new heavy metal pollution in effluent.

scholarly journals Optimization of the electro coagulation process for the removal of cadmium from aqueous solution using RSM

2019 ◽  
Vol 26 (4) ◽  
pp. 52-64
Author(s):  
Zahraa Adil Sadoon ◽  
Mohanad J. M-Ridha
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Room Temperature ◽  
Operating Time ◽  
Ion Concentration ◽  
Best Value ◽  
Nacl Concentration ◽  
Initial Ph ◽  
Electro Coagulation ◽  
The Impact

A certain of industrialized wastewater streams include heavy metal ions, should be efficiently removal before the reuse or discharge of treated waters could occur. In this work, the removal of cadmium from aqueous solution was carried out by electro coagulation using aluminum electrodes as anode and cathode. Electro coagulation cell of 1litter was used in this research. Several operating parameters on the removal efficiency of cadmium were investigated, such as initial pH, voltage, initial cadmium  ion concentration, NaCl concentration, spacing between electrodes, and  type of electrode . The Cd(II) concentration (50 ,100,150,200 ppm),( stirring speed 120 rpm) at room temperature . A pH was use   to be a constant best value when studied the  impact  of voltage values were chosen as 6,10,  and 14 increasing voltage  increased Cd(II) removals significantly Removal of 30.1%, 94.1%, 97.4%. The optimum removal efficiency of 97.4 % was achieved at a voltage of 14 V and pH 5 using (Al/Al.) electrodes, within 60 min of operating time. The concentration of NaCl was 0.6 g/l with a 0. 5 cm spacing between the electrodes.

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.

scholarly journals Efficient Sequestration of Hexavalent Chromium by Graphene-Based Nanoscale Zero-Valent Iron Composite Coupled with Ultrasonic Pretreatment

2021 ◽  
Vol 18 (11) ◽  
pp. 5921
Author(s):  
Haiyan Song ◽  
Wei Liu ◽  
Fansheng Meng ◽  
Qi Yang ◽  
Niandong Guo
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Inhibitory Effect ◽  
Ultrasonic Cavitation ◽  
Zero Valent Iron ◽  
Ultrasonic Pretreatment ◽  
Nanoscale Zero Valent Iron ◽  
Passivation Layers ◽  
Initial Ph ◽  
Two Phases

Nanoscale zero-valent iron (nZVI) has attracted considerable attention for its potential to sequestrate and immobilize heavy metals such as Cr(VI) from an aqueous solution. However, nZVI can be easily oxidized and agglomerate, which strongly affects the removal efficiency. In this study, graphene-based nZVI (nZVI/rGO) composites coupled with ultrasonic (US) pretreatment were studied to solve the above problems and conduct the experiments of Cr(VI) removal from an aqueous solution. SEM-EDS, BET, XRD, and XPS were performed to analyze the morphology and structures of the composites. The findings showed that the removal efficiency of Cr(VI) in 30 min was increased from 45.84% on nZVI to 78.01% on nZVI/rGO and the removal process performed coupled with ultrasonic pretreatment could greatly shorten the reaction time to 15 min. Influencing factors such as the initial pH, temperature, initial Cr(VI) concentration, and co-existing anions were studied. The results showed that the initial pH was a principal factor. The presence of HPO42−, NO3−, and Cl− had a strong inhibitory effect on this process, while the presence of SO42− promoted the reactivity of nZVI/rGO. Combined with the above results, the process of Cr(VI) removal in US-nZVI/rGO system consisted of two phases: (1) The initial stage is dominated by solution reaction. Cr(VI) was reduced in the solution by Fe2+ caused by ultrasonic cavitation. (2) In the following processes, adsorption, reduction, and coprecipitation coexisted. The addition of rGO enhanced electron transportability weakened the influence of passivation layers and improved the dispersion of nZVI particles. Ultrasonic cavitation caused pores and corrosion at the passivation layers and fresh Fe0 core was exposed, which improved the reactivity of the composites.

The fate of peroxyl radicals in aqueous solution

1997 ◽  
Vol 35 (4) ◽  
pp. 9-15 ◽  
Author(s):  
Clemens von Sonntag ◽  
Peter Dowideit ◽  
Fang Xingwang ◽  
Ralf Mertens ◽  
Pan Xianming ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Aromatic Compounds ◽  
Advanced Oxidation Processes ◽  
Room Temperature ◽  
Oxidative Degradation ◽  
High Reactivity ◽  
Peroxyl Radicals ◽  
Oh Radical ◽  
Oxidation Processes ◽  
Water And Wastewater

The reactions of peroxyl radicals occupy a central role in oxidative degradation. Under the term Advanced Oxidation Processes in drinking-water and wastewater processing, procedures are summarized that are based on the formation and high reactivity of the OH radical. These react with organic matter (DOC). With O2, the resulting carbon-centered radicals O2 give rise to the corresponding peroxyl radicals. This reaction is irreversible in most cases. An exception is hydroxycyclohexadienyl radicals which are formed from aromatic compounds, where reversibility is observed even at room temperature. Peroxyl radicals with strongly electron-donating substituents eliminate O2.−, those with an OH-group in a-position HO2.. Otherwise organic peroxyl radicals decay bimolecularly. The tetroxides formed in the first step are very short-lived intermediates and decay by various pathways, leading to molecular products (alcohols, ketones, esters and acids, depending on the precursor), or to oxyl radicals, which either fragment by scission of a neighbouring C-C bond or, when they carry an a-hydrogen, undergo a (water-assisted) 1,2-H-shift.

Adsorption of Nitrobenzene and Benzoic Acid from Aqueous Solution by All-Silica Zeolite Beta

2011 ◽  
Vol 183-185 ◽  
pp. 1378-1382 ◽  
Author(s):  
Qing Dong Qin ◽  
Jun Ma ◽  
Da Fang Fu
Keyword(s):  
Aqueous Solution ◽  
Benzoic Acid ◽  
Contact Time ◽  
Batch Reactor ◽  
Zeolite Beta ◽  
Reactor System ◽  
Equilibrium Isotherm ◽  
Initial Concentration ◽  
Initial Ph ◽  
Increasing Temperature

All-silica zeolite beta (BEA) was tested for the ability to remove nitrobenzene and benzoic acid from aqueous solution. The effect of contact time, temperature, initial concentration and initial pH were investigated in a batch reactor system. Adsorption of nitrobenzene decreased with increase in temperature. The equilibrium isotherm was L-shaped. Nitrobenzene adsorption was independent of pH. Adsorption of benzoic acid increased with increasing temperature from 5 °C to 22 °C and decreased with increasing temperature from 22°C to 32 °C. The equilibrium isotherm was approximately S-shaped. Benzoic acid adsorption was dependent of pH. At pH8.0, benzoic acid can also be adsorbed effectively. The results above confirmed that BEA had the potential to be utilized as relatively effective adsorbent for nitrobenzene and benzoic acid removal.

scholarly journals Removal of Reactive Dyes by Electro Coagulation Process from Aqueous Solution

2020 ◽  
Vol 26 (2) ◽  
pp. 14-28
Author(s):  
Zahraa A Sadoon ◽  
Mohanad J. M-Ridha
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Room Temperature ◽  
Reactive Dyes ◽  
Nacl Concentration ◽  
The World ◽  
Aluminum Electrodes ◽  
Electro Coagulation ◽  
The Impact ◽  
Dyes Removal

The presence of dyes in wastewater has become a major issue all over the world. The discharge of dyes in the environment is concerned for both toxicological and esthetical reasons. In this study, the removal of dyes from aqueous solution by electrocoagulation using aluminum electrodes as cathode and anode were investigated with the electrocoagulation cell of 1litter. The study included: the impact of various operating parameters on the dyes removal efficiency like pH, NaCl concentration, distance between electrodes, voltage, initial dyes concentration and type of electrodes. The dye (congo red) concentrations were (50, 100, 150, and 200 ppm), stirring speed was 120 rpm at room temperature. pH used was maintained constant. The impact of voltage values was chosen as 6, 10, and 14 Volts. On increasing voltage dyes, removals increased significantly. The higher removal efficiency of dyes (99.9%) was achieved at (30) minutes for (Al/Al) electrodes at pH 6.5-7 and voltage 14 Volts. The results showed that the best amount of sodium chloride was found to be 600 ppm in dyes, voltage of 14 Volts, and best gap between the electrodes as 0.5 cm.

Kinetic Studies of Adsorption of Disperse Blue 2BLN from Aqueous Solution by Expanded Graphite

2011 ◽  
Vol 148-149 ◽  
pp. 357-360
Author(s):  
Jin Bo Huang ◽  
Min Cong Zhu ◽  
Zhi Fang Zhou ◽  
Hong Xia Zhang
Keyword(s):  
Aqueous Solution ◽  
Room Temperature ◽  
Ph Value ◽  
Expanded Graphite ◽  
Kinetic Studies ◽  
Second Order ◽  
Batch Adsorption ◽  
Initial Ph ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order

Expanded graphite (EG) was prepared by microwave irradiation and evaluated as adsorbent for the removal of disperse blue 2BLN (DB) from aqueous solution by the batch adsorption technique under different conditions of initial pH value, adsorbent dosage, initial dye concentration and contact time. The experimental data were analyzed considering pseudo-first-order, pseudo-second-order and intra-particle diffusion approaches. The adsorption kinetics at room temperature could be expressed by the pseudo second order model very well. The results indicate that the adsorption rate is fast enough and more than eighty percent of the adsorbed DB can be removed in the first 15 min at room temperature, which makes the process practical for industrial application.

scholarly journals Research on the Degradation of Oxacillin in Water by Strong Ionization Discharge

2021 ◽  
Author(s):  
Rongjie Yi ◽  
Qi Zhang ◽  
Chengwu Yi
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Theoretical Basis ◽  
Input Voltage ◽  
Initial Concentration ◽  
Treatment Conditions ◽  
Effective Removal ◽  
Initial Ph ◽  
Strong Ionization Discharge ◽  
By Products

The degradation of oxacillin in aqueous solution by strong ionization dielectric barrier discharge (DBD) was explored. The effects of input voltage, initial pH, initial concentration of solution and hydroxyl (·OH) inhibitor on the removal efficiency of OXA were investigated. The results showed that the removal efficiency of OXA with initial concentration of 20mg/L reached 91.5% under the optimal treatment conditions of 3.8 kV and 7.3 pH. With the higher voltage and the lower initial concentration, the removal effect was better. The pH of the solution has little effect on the removal efficiency, and the removal effect is the best in neutral aqueous solution. The inhibition effect of TBA was stronger than that of CO32- and HCO3-. Moreover, ·OH was the main active substance in the process of strong ionization discharge, which played a major role in the removal of OXA. In addition, two main by-products were identified, the transformation pathways including hydroxylation (+16 Da), decarboxylation (-44 Da) were observed. This study provided a theoretical basis for the effective removal of antibiotics in water by strong ionization discharge.

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