scholarly journals Decomposition of Cyanide from Gold Leaching Tailingsby Using Sodium Metabisulphite and Hydrogen Peroxide

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Dongzhuang Hou ◽  
Lang Liu ◽  
Qixing Yang ◽  
Bo Zhang ◽  
Huafu Qiu ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Comparative Study ◽  
Contact Time ◽  
Synergetic Effect ◽  
Economic Conditions ◽  
Gold Mine ◽  
Optimal Conditions ◽  
Gold Leaching ◽  
Sodium Metabisulphite ◽  
To Come

Cyanidation is widely used by most gold mine worldwide and will remain prevail in years (or decades) to come, while cyanide is hazardous, toxic pollutants whose presence in wastewater and tailings can seriously affect human and its environment; hence, it is necessary to control these contaminants. The purpose of this study was to examine the effects through the investigation of changes in pH, concentration, and contact time, and the optimal conditions were obtained. It has been proven that the decomposition of cyanide in solution and tailings increased as the alkalinity in the presence of 0.5 g/L Na2S2O5. An increase in H2O2 (30%) concentration (from 1 to 4 mL/L) increased the decomposition in solution, while the effect on removing cyanide was better when pH was 9 than 8 and 10 in tailings. The cyanide in tailings decreased in the first 4 h and increased after 4 h. The effective and economic conditions for maximum decomposition of cyanide from leach tailings are first treated in 0.5 g/L Na2S2O5 at pH 10 for 3 hours and then 2 mL/L H2O2 (30%) is added to the tailings at pH 9 for 4 hours through comparative study. The findings provide the basis to optimize the decomposition of cyanide from gold leaching tailings in mining or backfilling by using the synergetic effect of Na2S2O5 and H2O2.

A Two-step Electrodeposition of Pd-Cu/Cu2O Nanocomposite on FTO Substrate for Non-enzymatic Hydrogen Peroxide Sensor

2021 ◽  
Vol 17 ◽  
Author(s):  
Ke Huan ◽  
Li Tang ◽  
Dongmei Deng ◽  
Huan Wang ◽  
Xiaojing Si ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Cyclic Voltammetry ◽  
Photoelectron Spectroscopy ◽  
Chemical Structure ◽  
Pd Nanoparticles ◽  
Optimal Conditions ◽  
Potential Oscillation ◽  
X Ray Diffraction ◽  
X Ray

Background: Hydrogen peroxide (H2O2) is a common reagent in the production and living, but excessive H2O2 may enhance the danger to the human body. Consequently, it is very important to develop economical, fast and accurate techniques for detecting H2O2. Methods: A simple two-step electrodeposition process was applied to synthesize Pd-Cu/Cu2O nanocomposite for non-enzymatic H2O2 sensor. Cu/Cu2O nanomaterial was firstly electrodeposited on FTO by potential oscillation technique, and then Pd nanoparticles were electrodeposited on Cu/Cu2O nanomaterial by cyclic voltammetry. The chemical structure, component, and morphology of the synthesized Pd-Cu/Cu2O nanocomposite were characterized by X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. The electrochemical properties of Pd-Cu/Cu2O nanocomposite were studied by cyclic voltammetry and amperometry. Results: Under optimal conditions, the as-fabricated sensor displayed a broad linear range (5-4000 µM) and low detection limit (1.8 µM) for the determination of H2O2. The proposed sensor showed good selectivity and reproducibility. Meanwhile, the proposed sensor has been successfully applied to detect H2O2 in milk. Conclusion: The Pd-Cu/Cu2O/FTO biosensor exhibits excellent electrochemical activity for H2O2 reduction, which has great potential application in the field of food safety.

Control of 2-Methylisoborneol and Geosmin by Ozone and Peroxone: A Pilot Study

1992 ◽  
Vol 25 (2) ◽  
pp. 291-298 ◽  
Author(s):  
B. Koch ◽  
J. T. Gramith ◽  
M. S. Dale ◽  
D. W. Ferguson
Keyword(s):  
Hydrogen Peroxide ◽  
Ferrous Sulfate ◽  
Contact Time ◽  
Pilot Scale ◽  
Ozone Dose ◽  
Ammonia Addition ◽  
Removal Efficiencies ◽  
Odorous Compounds ◽  
Water District ◽  
Percent Removal

A pilot-scale study of ozone and PEROXONE (ozone in combination with hydrogen peroxide) for the removal of the odorous compounds 2-methylisoborneol (MIB) and geosmin in drinking water has been conducted at the Metropolitan Water District of Southern California. The study investigated the effects of ozone dosage, ratio of hydrogen peroxide to ozone (H202/03), and contact time. It was found that MIB and geosmin removal increased with higher applied ozone doses, but longer contact times over the range of 6-12 min were not significant. It was determined that 80-90 percent removal could be achieved with an ozone dose of approximately 4.0 mg/l, as compared to an ozone dose of approximately 2.0 mg/l at a H202/03 ratio of 0.2. Also investigated were the effects of alternative contactor configurations, ferrous sulfate as an alternative coagulant, bromide and ammonia addition, and simulated turbidity on the removal efficiencies of the two odorous compounds.

scholarly journals A Fuzzy MADM Approach for Selecting the Best Cyanide Removal Method from a Gold Mine Wastewater

2021 ◽  
Author(s):  
Mohammad Hayati ◽  
Seyed Mohammad Seyed Alizadeh Ganji ◽  
Seyed Hadi Shahcheraghi
Keyword(s):  
Hydrogen Peroxide ◽  
Decision Making ◽  
Sodium Hypochlorite ◽  
Fuzzy Topsis ◽  
Gold Mine ◽  
Calcium Hypochlorite ◽  
Gold Mines ◽  
Removal Method ◽  
Fuzzy Delphi ◽  
Cyanide Removal

Abstract The cyanidation process is the most common method applied for the extraction of gold and silver in the hydrometallurgy industry, in which, sodium cyanide is used as a leaching agent. Therefore, the wastewater of gold mines contains a wide variety of cyanide ions needing to be removed before these wastewaters can be discharged to the receiving environments. In this study, a fuzzy multi-attribute decision-making approach (Fuzzy Delphi AHP and Fuzzy TOPSIS) was used for selecting the best cyanide removal method from the wastewater of Muteh gold mine. According to the experts' opinion, three methods including calcium hypochlorite, hydrogen peroxide and sodium hypochlorite were selected as alternatives. Then, by introducing the criteria influencing decision making, including cyanide removal ability, cost of process, amount of material consumed, time, pH, ease of performance and safety, and performing separated experiments, the criteria for each of three methods were determined. Finally, sodium hypochlorite was proposed as the best method for eliminating cyanide from wastewater. It was found that the rank of methods was as sodium hypochlorite (0.517) > calcium hypochlorite (0.474) > hydrogen peroxide (0.463).

scholarly journals COHERENT SYNCHRONIZATION OF PYRIDINE DIMERIZATION REACTIONS AND DECOMPOSITION OF “GREEN OXIDANTS” – H2O2 AND N2O

2021 ◽  
Vol 0 (4) ◽  
pp. 6-11
Author(s):  
I.T. Nagieva ◽  
◽  
N.I. Ali-zadeh ◽  
T.М. Nagiev ◽  
◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Nitrous Oxide ◽  
Gas Phase ◽  
Atmospheric Pressure ◽  
Raw Materials ◽  
Oxidizing Agent ◽  
Optimal Conditions ◽  
Pyridine Bases ◽  
Pharmaceutical Industries ◽  
Oxidation By Hydrogen Peroxide

In recent years, hydrogen peroxide and nitrous oxide (1) "green oxidants" – have attracted much attention of researchers as a selective oxidizing agent for the catalytic oxidation of pyridine bases. In this regard, the reaction of pyridine oxidation by hydrogen peroxide and nitrous oxide under homogeneous conditions, in the gas phase, without the use of catalysts, at atmospheric pressure, has been experimentally investigated. Areas of selective oxidation of pyridine with hydrogen peroxide and nitrous oxide have been established, and optimal conditions have been found for obtaining valuable raw materials required in the petrochemical, chemical, and pharmaceutical industries

A comparative study of the electrogeneration of hydrogen peroxide using Vulcan and Printex carbon supports

Carbon ◽  
2011 ◽  
Vol 49 (8) ◽  
pp. 2842-2851 ◽  
Author(s):  
M.H.M.T. Assumpção ◽  
R.F.B. De Souza ◽  
D.C. Rascio ◽  
J.C.M. Silva ◽  
M.L. Calegaro ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Comparative Study ◽  
Carbon Supports

A comparative study between Keggin-type tungstophosphates and tungstosilicates in the oxidation of cyclooctane with hydrogen peroxide

2004 ◽  
Vol 222 (1-2) ◽  
pp. 159-165 ◽  
Author(s):  
M. Salete S. Balula ◽  
Isabel C.M.S. Santos ◽  
Mário M.Q. Simões ◽  
M. Graça P.M.S. Neves ◽  
José A.S. Cavaleiro ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Comparative Study ◽  
Keggin Type

Phosphorus and Nitrogen Removal from Sewage by Modified Honeycomb Cinder

2013 ◽  
Vol 726-731 ◽  
pp. 2931-2935
Author(s):  
Qi Bin Liang ◽  
Yun Gen Liu ◽  
Kun Tian
Keyword(s):  
Nitrogen Removal ◽  
Phosphorus Removal ◽  
Contact Time ◽  
Low Cost ◽  
Ammonia Nitrogen ◽  
Domestic Sewage ◽  
Operating Conditions ◽  
Optimal Conditions ◽  
Batch Experiments ◽  
Adsorption Capacities

The study aimed at phosphorus and nitrogen removal by honeycomb cinder modified with Zinc chloride (ZnCl2). By bench-scale batch experiments, honeycomb cinders with different modification time and ZnCl2 dosage were modified and its adsorption capacities were evaluated by methylence blue as the adsorbate. Under the optimal modification conditions, large amount modified honeycomb cinders were prepared to remove the phosphorus and nitrogen from domestic sewage, which different operating conditions of honeycomb cinders dosage, and contact time were considered. The results show that removal efficiencies of total phosphate (TP), orthophosphate (PO43-P), total nitrogen (TN) and ammonia nitrogen (NH4+-N) could reach 89.9%, 96.7%, 18.9% and 23.3% under the optimal conditions, respectively. Modified honeycomb cinders might be an effective and low cost adsorbent for phosphorus removal.

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