scholarly journals Oxidation of Thiosulfate with Oxygen Using Copper (II) as a Catalyst

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 387 ◽  
Author(s):  
Juan González Lara ◽  
Francisco Cardona ◽  
Antonio Vallmajor ◽  
Montserrat Cadevall
Keyword(s):  
Kinetic Study ◽  
Oxygen Pressure ◽  
Metallic Coating ◽  
Electronic Scrap ◽  
Initial Concentration ◽  
Industrial Sectors ◽  
The Future ◽  
Ppm Level ◽  
Thiosulfate Concentration

Thiosulfate effluents are generated in the photography and radiography industrial sectors, and in a plant in which thiosulfates are used to recover the gold and silver contained in ores. Similar effluents also containing thiosulfate are those generated from the petrochemical, pharmaceutical and pigment sectors. In the future, the amounts of these effluents may increase, particularly if the cyanides used in the extraction of gold and silver from ores are substituted by thiosulfates, or if the same happens to electronic scrap or in metallic coating processes. This paper reports a study of the oxidation of thiosulfate, with oxygen using copper (II) as a catalyst, at a pH between 4 and 5. The basic idea is to avoid the formation of tetrathionate and polythionate, transforming the thiosulfate into sulfate. The nature of the reaction and a kinetic study of thiosulfate transformation, by reaction with oxygen and Cu2+ at a ppm level, are determined and reported. The best conditions were obtained at 60 °C, pH 5, with an initial concentration of copper of 53 ppm and an oxygen pressure of 1 atm. Under these conditions, the thiosulfate concentration was reduced from 1 g·L−1 to less than 20 ppm in less than three hours.

scholarly journals Navantia’s Shipyard 4.0 model overview

2018 ◽  
Vol 11 (22) ◽  
pp. 77 ◽  
Author(s):  
Ángel Recamán Rivas
Keyword(s):  
Industry 4.0 ◽  
Implementation Process ◽  
Special Focus ◽  
Industrial Transformation ◽  
Shipbuilding Industry ◽  
Industrial Sectors ◽  
The Future ◽  
The Government ◽  
Willingness To Cooperate ◽  
Expected Outcomes

Navantia finished the analysis of the concept Industry 4.0 in 2016 and its application to the naval shipbuilding industry, referred to herein as Shipyard 4.0. The implementation process has begun with several projects that involved various technologies. In order to incorporate them in the new project, for naval vessels and systems, special focus has been put in the future F-110 frigate.This document aims to provide an overview of the Shipyard 4.0 model and a brief discussion regarding the projects launched for its implementation in Navantia. The initiative 4.0 is a key development vector across all the industrial sectors in the future and its expected outcomes match the ones established by the Government of Colombia in its “Plan de Transformación Industrial” (Plan of Industrial Transformation). In this context, the new frigate program (PES) is a unique opportunity to engage the local industry, in which Navantia offers its willingness to cooperate.

scholarly journals Removal of nickel ions from synthetic wastewater by bulk liquid membrane

2021 ◽  
Vol 28 (1) ◽  
pp. 15-27
Author(s):  
Nashwan H. Yousif ◽  
Hussain M. Flayeh
Keyword(s):  
Kinetic Study ◽  
Liquid Membrane ◽  
Synthetic Wastewater ◽  
Bulk Liquid ◽  
Optimum Process ◽  
Process Conditions ◽  
Bulk Liquid Membrane ◽  
Nickel Ions ◽  
Initial Concentration ◽  
Extraction And Separation

Heavy metals extraction and separation from industrial wastewater has becomes a majorconcern for both environmental and economic reasons. This paper describes a comparetive kinetic study ofthe removal and recovery of nickel ions from aqueous solutions by bulk liquid membrane (BLM) usingcoupled faciletated transport mechenisms and two carriers of diffarent chemical nature: tributyl phosphate(TBP) and di-2-ethylhexyl phosphoric acid (D2EHPA). Xylene oil was used as the liquid membrane phase.In addition, environmentall friendly materials such as vegetable oils (soybean oil) used as a suitablereplacement for the conventional organic solvents in this work. A comprahensive kinetic study was carriedout and effact of various parameters such as, pH of feed and stripping phase, initial concentration of metalions, concentration of extractant in the membrane phase and stirring speed were studied. The chelatingcharacteristics of EDTA was used as stripping agent as well as precipitating agent to enhance the transportefficiency of the nickel ions. The extraction and recovery efficiency were found as 80.89% and 87.80%respectively for nickel ions, At the optimum process conditions for transport of Ni(II) were found as follows:pH in the feed phase (4), pH in the stripping phase (8), initial concentration of nickel ions (120 ppm), carrierconcentration (12%) (v/v) TBP and stirring speed (125±10 rpm), respectively.

Degradation of safranin by heterogeneous Fenton processes using peanut shell ash based catalyst

2019 ◽  
Vol 79 (7) ◽  
pp. 1367-1375
Author(s):  
Amir Ikhlaq ◽  
Hafiza Zara Anwar ◽  
Farhan Javed ◽  
Saba Gull
Keyword(s):  
Research Work ◽  
Agitation Speed ◽  
Peanut Shell ◽  
H2o2 Concentration ◽  
Fenton Process ◽  
Heterogeneous Fenton ◽  
Initial Concentration ◽  
Industrial Sectors ◽  
Efficient Performance ◽  
Maximum Decolorization

Abstract Today, dyes are one of the major problematic pollutants in the environment and are broadly used in several industrial sectors. In the current research work, decolorization of safranin (basic dye) from aqueous solution was investigated using iron-impregnated peanut shell ash (Fe-PSA) as a catalyst in the UV-assisted heterogeneous Fenton process (Fe-PSA/H2O2/UV). The effect of parameters such as H2O2 concentration, catalyst dose, pH, initial dye concentration, temperature, and agitation speed was studied. The maximum decolorization of safranin was achieved at optimum parametric values of reagent dose = 8 mM, catalyst dose = 0.5 g, pH = 3, initial concentration of safranin = 50 ppm, temperature = 25 °C, and agitation speed = 200 rpm. The results revealed the efficient performance of Fe-PSA as catalyst in the Fe-PSA/H2O2/UV process for safranin treatment.

Study of the Literature to Assess the Future of India’s Shipbuilding Industry

2003 ◽  
Vol 19 (04) ◽  
pp. 246-254
Author(s):  
Howard M. Bunch
Keyword(s):  
Cutting Edge ◽  
Delivery Time ◽  
Shipbuilding Industry ◽  
Industrial Sectors ◽  
The Future ◽  
World Class ◽  
Future Direction ◽  
The Moment

Several industrial sectors within India are at the cutting edge of technology and world class in their sector capabilities. Sadly, the shipbuilding industry is not one of these sectors at the moment. It is uncompetitive in cost and in delivery time, and most of the major shipyards must be heavily subsidized to remain open. The reason for an investigation of the Indian shipbuilding industry would be to develop a better understanding of why it is so uncompetitive and to project its future direction.

The Future of EMAS – 10 years European Environmental Management and Audit Scheme

elni Review ◽  
2005 ◽  
pp. 12-15
Author(s):  
Thomas Kiel
Keyword(s):  
Environmental Management ◽  
Financial Services ◽  
Policy Instruments ◽  
Iso 14001 ◽  
European Economic Area ◽  
The European Union ◽  
Economic Sectors ◽  
Industrial Sectors ◽  
The Future ◽  
The Eu

The Eco-Management and Audit Scheme (EMAS) is the European Union (EU) voluntary scheme for organisations willing to commit themselves to evaluate, improve and report on their environmental performances. The scheme was launched in April 1995 and was originally restricted to companies of industrial sectors. EMAS II revision has opened the instrument since 2001 to all economic sectors including public and private services. In addition, EMAS was strengthened by the integration of parts of EN ISO 14001 standard as environmental management system requirement; by adopting an attractive logo to signal EMAS registration to the public; and by considering more strongly indirect environmental aspects such as those related to external traffic, financial services or administrative and planning decisions. Participating in EMAS is voluntary and extends to public or private organisations operating in the EU and the European Economic Area (EEA) – Iceland, Liechtenstein and Norway. In all new member states the EMAS Regulation came into force with the association to the EU in May 2004. On 15 November 2004 a revised version of ISO environmental management standard 14001 was published. The author takes this for opportunity to think about the future developments of EMAS. After ten years practice of a new and proactive instrument in voluntary environmental management a turning point is reached. The commission has to decide whether to give EMAS a permanent place within the canon of environmental policy instruments and to strengthen its use by different means or to restrain from EU management requirements and leave further decisions on development of environmental management tools to the private market.

scholarly journals Determination of Dissolution Rates of Ag Contained in Metallurgical and Mining Residues in the S2O32−-O2-Cu2+ System: Kinetic Analysis

Minerals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 309 ◽  
Author(s):  
Julio Juárez Tapia ◽  
Francisco Patiño Cardona ◽  
Antonio Roca Vallmajor ◽  
Aislinn Teja Ruiz ◽  
Iván Reyes Domínguez ◽  
...  
Keyword(s):  
Kinetic Study ◽  
Dissolution Rate ◽  
Catalytic Effect ◽  
Particle Diameter ◽  
Favorable Effect ◽  
Leaching Rate ◽  
Materials Used ◽  
Mining Residues ◽  
Thiosulfate Concentration

The materials used to conduct kinetic study on the leaching of silver in the S2O32−-O2-Cu2+ system were mining residues (tailings) from the Dos Carlos site in the State of Hidalgo, Mexico, which have an estimated concentration of Ag = 71 g∙ton−1. The kinetic study presented in this paper assessed the effects of the following variables on Ag dissolution rate: particle diameter (d0), temperature (T), copper concentration [Cu2+], thiosulfate concentration [S2O32−], pH, [OH−], stirring rate (RPM), and partial pressure of oxygen (PO2). Temperature has a favorable effect on the leaching rate of Ag, obtaining an activation energy (Ea) = 43.5 kJ∙mol−1 in a range between 288 K (15 °C) and 328 K (55 °C), which indicates that the dissolution reaction is controlled by the chemical reaction. With a reaction order of n = 0.4, the addition of [Cu2+] had a catalytic effect on the leaching rate of silver, as opposed to not adding it. The dissolution rate is dependent on [S2O32−] in a range between 0.02 mol·L−1 and 0.06 mol·L−1. Under the studied conditions, variables d0, [OH−] and RPM did not have an effect on the overall rate of silver leaching.

Stream Temperature Evolution in Switzerland: Recent past and future

2020 ◽  
Author(s):  
Adrien Michel ◽  
Tristan Brauchli ◽  
Nander Wever ◽  
Bettina Schaefli ◽  
Michael Lehning ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Temperature ◽  
Stream Temperature ◽  
Freshwater Ecosystems ◽  
Temperature Evolution ◽  
Electricity Production ◽  
Strong Impact ◽  
Climate Change Scenarios ◽  
Industrial Sectors ◽  
The Future

<p>Climate change has already affected many components of our natural environment which are well described in the literature. Water temperature has received less interest despite the fact that it is recognized as key variable for assessing water quality of freshwater ecosystems in streams and lakes. It influences the metabolic activity of aquatic organisms but also biochemical cycles. Water temperature is also a key variable for many industrial sectors, e.g. as cooling water for electricity production or in large buildings, and for the spreading of some diseases affecting fishes.</p><p>It is very likely that climate change has and will also have an important effect on the temperature of streams. This study (Michel et al., 2020) investigates first the past temperature evolution and corresponding discharge in Switzerland since 1979, showing an increase of +0.33 ± 0.03° per decade in water temperature. Some differences between catchment type (alpine vs. lowland) and some important seasonal features are identified.</p><p>In a second step, the response of selected catchments in Switzerland to the future forcing is numerically assessed using the CH2018 climate change scenarios for Switzerland. The approach uses a sequence of physical models including Snowpack, Alpine3D and StreamFlow. The CH2018 scenarios have been down-scaled to hourly resolution using a novel approach based on a delta method which preserves the seasonal aspect of the climate change scenario. The results show an increase in temperature for any of the RCP (2.6, 4.5, and 8.5) and a strong impact of climate change on alpine catchments caused by changes in snowfall/melt and glacier melt. As a consequence, river ecosystems including fish populations will be severely impacted and current legal limits for the usage of water for cooling in the energy production sector and in the industry will be reached more often in the future.</p><p>REFERENCES</p><p>Michel, A., Brauchli, T., Lehning, M., Schaefli, B., & Huwald, H.: <em>Stream temperature and discharge evolution in Switzerland over the last 50 years: annual and seasonal behaviour</em> , Hydrol. Hydrol. Earth Syst. Sci., 24, 115–142, https://doi.org/10.5194/hess-24-115-2020, 2020.</p>

scholarly journals Influence of Storage Conditions on the Stability of Vitamin D3 and Kinetic Study of the Vitamin Degradation in Fortified Canola Oil during the Storage

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Mina Zareie ◽  
Azam Abbasi ◽  
Shiva Faghih
Keyword(s):  
Kinetic Study ◽  
Vitamin D3 ◽  
Canola Oil ◽  
Room Temperature ◽  
Storage Temperature ◽  
Storage Condition ◽  
Storage Conditions ◽  
Initial Concentration ◽  
The Stability ◽  
Polyethylene Terephthalate Bottles

Nowadays, fortified vegetable oils with vitamin D3 are widely available in different countries. In this study, the influence of storage conditions including light, air, storage temperature, and time on vitamin D3 retention in fortified canola oil was evaluated. Moreover, a kinetic study on vitamin D3 degradation in the oil was done. To this aim, fortified canola oil was prepared at two initial concentrations of 6.87 mg·kg−1 and 13.8 mg·kg−1 and then filled in transparent and dark-brown polyethylene terephthalate bottles at two filling levels of 50% and 100%. Samples were kept in two temperatures of 4°C and room temperature (27°C). The retention of vitamin D3 in different samples showed that the vitamin content was affected by the packaging type, storage temperature, and initial concentration. Vitamin D3 in the samples with a lower concentration of the vitamin which was stored in the refrigerator showed the highest retention (91%) after 70 days of storage, and the samples with higher initial concentration packed in transparent containers which were stored at room temperature (RT) showed the greatest loss (55.6%). Results of the kinetic study also showed that vitamin D3 was affected by storage condition. The half-life of the vitamin D3 differed from 96 to 577 days depending on the storage condition.

scholarly journals Leaching of Silver and Gold Contained in a Sedimentary Ore, Using Sodium Thiosulfate; A Preliminary Kinetic Study

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 159 ◽  
Author(s):  
Edmundo Roldán-Contreras ◽  
Eleazar Salinas-Rodríguez ◽  
Juan Hernández-Ávila ◽  
Eduardo Cerecedo-Sáenz ◽  
Ventura Rodríguez-Lugo ◽  
...  
Keyword(s):  
Activation Energy ◽  
Kinetic Study ◽  
Low Temperatures ◽  
Chemical Control ◽  
Reaction Order ◽  
Sodium Thiosulfate ◽  
The Other ◽  
Gold Leaching ◽  
Leaching Process ◽  
Thiosulfate Concentration

Some sedimentary minerals have attractive contents of gold and silver, like a sedimentary exhalative ore available in the eastern of Hidalgo in Mexico. The gold and silver contained represent an interesting opportunity for processing by non-toxic and aggressive leaching reagents like thiosulfate. The preliminary kinetic study indicated that the leaching process was poorly affected by temperature and thiosulfate concentration. The reaction order was −0.61 for Ag, considering a thiosulfate concentration between 200–500 mol·m−3, while, for Au, it was −0.09 for a concentration range between 32–320 mol·m–3. By varying the pH 7–10, it was found that the reaction order was n = 5.03 for Ag, while, for Au, the value was n = 0.94, considering pH 9.5–11. The activation energy obtained during the silver leaching process was 3.15 kJ·mol−1 (298–328 K), which was indicative of a diffusive control of the process. On the other hand, during gold leaching, the activation energy obtained was of 36.44 kJ·mol−1, which was indicative that this process was mixed controlled process, first at low temperatures by diffusive control (298–313 K) and then by chemical control (318–323 K).

UV photoelectrocatalytic degradation of m- cresol pollutant using TiO2 dip -coated stainless steel electrode system

2021 ◽  
pp. 123-131
Author(s):  
Jayabharathi Jayapal ◽  
M. Thenmozhi
Keyword(s):  
Stainless Steel ◽  
Kinetic Study ◽  
Photocatalytic Oxidation ◽  
Electrode System ◽  
Stainless Steel Electrode ◽  
Optimum Conditions ◽  
Steel Electrode ◽  
Initial Concentration ◽  
Photoelectrocatalytic Degradation ◽  
Uv Lamp

In the present study, the removal of m- cresol in an aqueous medium was studied by the photoelectrocatalytic (PEC) degradation by the TiO2 suspension on dip-coated stainless steel electrode under UV lamp of the wavelength of 352nm. The performance of the PEC method on the degradation of m- cresol was studied by made the comparison with the photocatalytic oxidation (PCO) method in terms of COD removal and kinetic study. In the PEC study on the degradation of m- cresol pollutant was studied by the various parameters such as initial concentration, pH, and the bias potential. The result found that the optimum degradation efficiency of m- cresol in the PEC and PCO methods were 79.6% and 39.8% at pH 5.0. The result showed that the kinetic constants (k) in the PEC and PCO methods were -0.0116 and -0.0058 under optimum conditions. The result found that the PEC method using TiO2 coated on stainless steel electrode is two times higher than the PCO method on the degradation of m- cresol.

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