scholarly journals Electrochemical Recovery to Overcome Direct Osmosis Concentrate-Bearing Lead: Optimization of Treatment Process via RSM-CCD

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3136
Author(s):  
Milaad Moosazade ◽  
Razieh Ashoori ◽  
Hamid Moghimi ◽  
Mohammad Ali Amani ◽  
Zacharias Frontistis ◽  
...  
Keyword(s):  
Operating Cost ◽  
Current Intensity ◽  
Electrolysis Time ◽  
High Concentration ◽  
Electrode Mass ◽  
Flotation Cell ◽  
Optimal Values ◽  
First Time ◽  
Central Composite ◽  
A Current

The use of electrochemistry is a promising approach for the treatment of direct osmosis concentrate that contains a high concentration of organic pollutants and has high osmotic pressure, to achieve the safe discharge of effluent. This work addresses, for the first time, this major environmental challenge using perforated aluminum electrodes mounted in an electrocoagulation–flotation cell (PA-ECF). The design of the experiments, the modeling, and the optimization of the PA-ECF conditions for the treatment of DO concentrate rich in Pb were explored using a central composite design (CCD) under response surface methodology (RSM). Therefore, the CCD-RSM was employed to optimize and study the effect of the independent variables, namely electrolysis time (5.85 min to 116.15 min) and current intensity (0.09 A to 2.91 A) on Pb removal. Optimal values of the process parameters were determined as an electrolysis time of 77.65 min and a current intensity of 0.9 A. In addition to Pb removal (97.8%), energy consumption, electrode mass-consumed material, and operating cost were estimated as 0.0025 kWh/m3, 0.217 kg Al/m3, and 0.423 USD/m3, respectively. In addition, it was found that DO concentrate obtained from metallurgical wastewater can be recovered through PA-ECF (almost 94% Pb removal). This work demonstrated that the PA-ECF technique could became a viable process applicable in the treatment of DO concentrate containing Pb-rich for reuse.

scholarly journals Organic Pollutants Removal from Olive Mill Wastewater Using Electrocoagulation Process via Central Composite Design (CCD)

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3522
Author(s):  
Abeer El Shahawy ◽  
Inas A. Ahmed ◽  
Mahmoud Nasr ◽  
Ahmed H. Ragab ◽  
Saedah R. Al-Mhyawi ◽  
...  
Keyword(s):  
Weight Loss ◽  
Current Density ◽  
Operating Cost ◽  
Oxygen Demand ◽  
Olive Mill Wastewater ◽  
Cod Removal ◽  
Electrolysis Time ◽  
Faraday’S Law ◽  
Central Composite ◽  
Olive Mill

Electrocoagulation (EC) was studied in this study as a potential alternative approach for treating Olive Mill Wastewater (OMW). Aluminum plates were utilized as anode and cathode to evaluate the removal of Chemical Oxygen Demand (COD) from OMW and the aluminum electrode’s weight loss. Central Composite Experimental Design (CCD) and Response Surface Methodology were used to optimize its performance. Anodes were weighed before and after each electrocoagulation experiment, to compare the experimental and the theoretical dissolved aluminum weights calculated using Faraday’s law. We discovered the following EC conditions for CCD: current density = 15 mA/cm2, pH = 4, and electrolysis time of 30 min. Under these conditions, the maximum COD removal ratio was 41%, equating to an Al weight loss of 288.89 g/m3 at an estimated operating cost of 1.60 USD/m3. According to the response optimizer, the most economical operating settings for COD removal efficiency of 58.888% are pH 4, a current density of 18.41 mA/cm2, electrolysis time of 36.82 min, and Al weight loss of 337.33 g/m3, with a projected running cost of 2.00 USD/m3.

scholarly journals Sequential three-step process for the treatment of slaughter house wastewater and its optimization using response surface modeling studies

2021 ◽  
Vol 11 (8) ◽  
Author(s):  
Aliya Said Khalfan Al-Saidi ◽  
Nabila Nasser Said Al Rashidi ◽  
M. Geetha Devi ◽  
Varghese Manappallil Joy
Keyword(s):  
Response Surface ◽  
Flow Rate ◽  
Current Density ◽  
Operating Cost ◽  
World Population ◽  
Electrolysis Time ◽  
Adsorption Column ◽  
Maximum Reduction ◽  
Slaughter House ◽  
A Current

AbstractThe rapid growth in the world population and fast developing industrialization have resulted in the acceleration of environmental pollution due to inadequate treatment methods accompanied by depletion of freshwater. The current research focused on the batch treatment of slaughter house wastewater (SWW) using the sequential three-step electro-coagulation (EC)–electro-oxidation (EO)–adsorption column (AC) processes and to compare the optimized values with the Omani National Standards for the application in irrigation purpose. The characterization of SWW before and after treatment was carried out by measuring chemical oxygen demand (COD), total organic carbon (TOC), total dissolved solids (TDS), turbidity, ammoniacal nitrogen (NH4–N) and conductivity. The optimization of the treatment processes was performed by response surface methodology (RSM) using central composite design. The maximum response obtained using EC unit was 99% with an operating cost of 2.78 USD/m3. The optimum treatment conditions in EC method were found to be 4.0 pH, electrolysis time of 30 min and electrolyte dosage of 5 g/L, with a current density of 18.11 mA/cm2. The maximum reduction in COD was 97% with an operating cost 0.32 USD/m3. The optimum COD reduction in EO method was 84.5% with an operating cost of 6.87 USD/m3. The optimum process parameters in the EO process were observed at 5.0 pH, 56.22 min electrolysis time with 5 g/L electrolyte dosage and a current density of 5 mA/cm2. The response shows 56.27% reduction in COD with an operating cost of 0.088 USD/m3. The study demonstrates that both EC and EO processes for the reduction of COD have a significant effect on the current density. Using adsorption column (AC) studies, the maximum reduction in COD was 76.8% with negligible operating cost. The optimum pH in the case of AC was 7.5, with an effluent flow rate of 8.63 mL/min, and the responses were found to be 76.067%, which indicates both pH and flow rate have significant effect on the % removal of COD.

PERSPECTIVE DEVELOPMENT OF WORLD PRODUCTION OF FEEDS FOR AQUACULTURE: ALTERNATIVE SOURCES OF RAW MATERIALS

2017 ◽  
pp. 67-78
Author(s):  
Lina Yurievna Lagutkina
Keyword(s):  
Raw Materials ◽  
Limiting Factors ◽  
Current Status ◽  
Feed Production ◽  
The World ◽  
Market Trends ◽  
Alternative Sources ◽  
World Industry ◽  
First Time ◽  
A Current

The author of the article discloses the prospects of development of the world feed production for aquaculture based on the analysis of key innovative technological and market trends. The author specifies that shortage, high cost, low ecological compatibility of traditional raw materials - fish flour - are among major limiting factors in the development of production of feeds for aquaculture. This fact, in turn, limits sustainable development of aquaculture both in Russia, and in the world in general. The article presents the overview of a current status of the world industry of feed production in aquaculture, where the regional situation is studied, as well. For the first time, there is given the outlook of innovative technologies in feed production based on the alternative sources of protein (on the example of projects of leading aquabiotechnological companies) which will determine industry’s objectives for the mid-term perspective.

scholarly journals Nanocrystalline TiO2Electrodes Exhibiting High Storage Capacity and Stability in Rechargeable Lithium Batteries

1995 ◽  
Vol 18 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Sui-Yang Huang ◽  
Ladislav Kavan ◽  
Andreas Kay ◽  
Michael Grätzel ◽  
Ivan Exnar
Keyword(s):  
Current Density ◽  
High Current Density ◽  
Discharge Voltage ◽  
Unit Weight ◽  
Nanocrystalline Films ◽  
Rechargeable Lithium Batteries ◽  
Capacity Loss ◽  
High Storage Capacity ◽  
First Time ◽  
A Current

Nanocrystalline TiO2films were explored for the first time as electrode material for a rechargeable lithium intercalation cell, i.e., Li/LiCF3SO3+ PC/TiO2. Two kinds of nanocrystalline films, TiO2F387 (Degussa) and TiO2colloid-240, were investigated. These films exhibited excellent performance renderings them a promising choice for secondary battery applications. At a current density of 0.01 mA/cm2, two voltage plateaus at 1.78 and 1.89 V were observed for TiO2F387 films during charge and discharge, respectively. The TiO2electrode charge capacity per unit weight rose with decreasing current density. The highest capacity, obtained at a current density of 0.005 mA/cm2and a final discharge voltage of 1.4 V, was 265 mAh/g corresponding to a lithium insertion ratio ofx= 0.8. Nanocrystalline TiO2colloid-240 films showed a similar performance. The cycle life of a TiO2colloid-240 cell at a high current density was found to be excellent; a capacity loss lower than 14% has been observed over 100 charge/discharge cycles.

scholarly journals Interpretation of the Repetitive Firing of Nerve Cells

1962 ◽  
Vol 45 (6) ◽  
pp. 1163-1179 ◽  
Author(s):  
M. G. F. Fuortes ◽  
Francoise Mantegazzini
Keyword(s):  
Nerve Cells ◽  
Principal Factor ◽  
Current Intensity ◽  
Moderate Intensity ◽  
Repetitive Firing ◽  
Important Process ◽  
Current Step ◽  
After Effects ◽  
Graded Activity ◽  
A Current

Eccentric cells of Limulus respond with repetitive firing to sustained depolarizing currents. Following stimulation with a step of current, latency is shorter than first interval and later intervals increase progressively. A shock of intensity twice threshold can evoke firing 25 msec. after an impulse. But in the same cell, a current step twice rheobase evokes a second impulse more than 50 msec. after the first, and current intensity must be raised to over five times rheobase to obtain a first interval of about 25 msec. Repetitive firing was evoked by means of trains of shocks. With stimuli of moderate intensity, firing was evoked by only some of the shocks and intervals between successive impulses increased with time. This is ascribed to accumulation of refractoriness with successive impulses. Higher frequencies of firing are obtained with shocks of intensity n x threshold than with constant currents of intensity n x rheobase. It is concluded that prolonged currents depress the processes leading to excitation and that (in the cells studied) repetitive firing is controlled both by the after-effects of firing (refractoriness) and by the depressant effects of sustained stimuli (accommodation). Development of subthreshold "graded activity" is an important process leading to excitation of eccentric cells, but is not the principal factor determining frequency of firing in response to constant currents.

ARCHITECTURE OF FLOWER-LIKE rGO/CNTs-LOADED CuxO NANOPARTICLES AND ITS PHOTOCATALYTIC PROPERTIES

NANO ◽  
2013 ◽  
Vol 08 (05) ◽  
pp. 1350052 ◽  
Author(s):  
BIN ZENG ◽  
XIAOHUA CHEN ◽  
XUTAO NING ◽  
CHUANSHENG CHEN ◽  
HUI LONG
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Performance ◽  
Degradation Process ◽  
Photocatalytic Properties ◽  
High Concentration ◽  
Graphene Oxides ◽  
Transmission Electron ◽  
Time Scanning ◽  
Reduced Graphene ◽  
First Time

Novel flower-like composite architecture was successfully synthesized by spray drying and post-calcinating method for the first time. Scanning electron microscopy and transmission electron microscopy observations confirmed that reduced graphene oxides/carbon nanotubes hybrid (rGO/CNTs) formed a flower-like micrometer structure and Cu2O , CuO ( Cu x O , x = 1 or 2) nanoparticles were decorated inside them. The photocatalytic properties were further investigated by evaluating the photodegradation of a pollutant methyl orange (MO). The experimental results indicated that this novel architecture enhanced photocatalytic performance with 96.2% decomposition of MO after 25 min in the presence of H 2 O 2 under visible light irradiation, which was much higher than that of Cu x O powders (33.2%). This could be attributed to the more efficient adsorption of MO molecules on flower-like rGO/CNTs and provide a high concentration of MO near to the Cu x O nanoparticles, thus promoting the photocatalytic degradation process.

Do we need medical leadership or medical engagement?

2015 ◽  
Vol 28 (3) ◽  
pp. 173-184 ◽  
Author(s):  
Peter Spurgeon ◽  
Paul Long ◽  
John Clark ◽  
Frank Daly
Keyword(s):  
Care Quality ◽  
Current Evidence ◽  
Organisational Performance ◽  
Content Type ◽  
Care Quality Commission ◽  
The Uk ◽  
Medical Leadership ◽  
First Time ◽  
Practical Implications ◽  
A Current

Purpose – The purpose of this paper is to address issues of medical leadership within health systems and to clarify the associated conceptual issues, for example, leadership versus management and medical versus clinical leadership. However, its principle contribution is to raise the issue of the purpose or outcome of medical leadership, and, in this respect, it argues that it is to promote medical engagement. Design/methodology/approach – The approach is to provide evidence, both from the literature and empirically, to suggest that enhanced medical engagement leads to improved organisational performance and, in doing so, to review the associated concepts. Findings – Building on current evidence from the UK and Australia, the authors strengthen previous findings that effective medical leadership underpins the effective organisational performance. Research limitations/implications – There is a current imbalance between the size of the databases on medical engagement between the UK (very large) and Australia (small but developing). Practical implications – The authors aim to equip medical leaders with the appropriate skill set to promote and enhance greater medical engagement. The focus of leaders in organisations should be in creating a culture that fosters and supports medical engagement. Social implications – This paper provides empowerment of medical professionals to have greater influence in the running of the organisation in which they deliver care. Originality/value – The paper contains, for the first time, linked performance data from the Care Quality Commission in the UK and from Australia with the new set of medical engagement findings.

scholarly journals Evaluation of volatile constituents, exudation of resin and occurrence of galls of Protium aracouchini (Aubl.) Marchand

2021 ◽  
Vol 5 (3) ◽  
pp. 88
Author(s):  
Thiago Augusto Araujo Correia Lima (in memorian) ◽  
Leonardo Pinto Cunha ◽  
José Eduardo Lahoz da Silva Ribeiro ◽  
Marcia Ortiz Mayo Marques ◽  
Maria da Paz Lima
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Chemical Constituents ◽  
Brazilian Amazon ◽  
High Concentration ◽  
Forest Reserve ◽  
Volatile Constituents ◽  
Aerial Parts ◽  
First Time ◽  
Time Information

Protium aracouchini (Aubl.) Marchand [sin Icica aracouchini Aubl.], which occurs in the Adolpho Ducke Forest Reserve, in the Brazilian Amazon, was evaluated for the presence of galls, for resin exudation and the composition of the essential oils from the aerial parts and the resin. The experiment to stimulate the exudation of resin from the trunk was conducted using a 2-chloroethylphosphonic acid solution. The resin produced after 40 days and the aerial parts had their essential oils extracted in a Clevenger apparatus and the volatile chemical constituents were analyzed using GC/MS. The non-oxygenated sesquiterpenes α-copaene (21.15%) and α-gurjunene (13.69%), in addition to the oxygenated sesquiterpene spathulenol (10.32%), were detected as the majority constituents of the essential oil of the leaves, and a concentration similar to that of α-gurjunene was found in the branches (13.28%). The resin essential oil showed a high concentration of hydrocarbon monoterpenes (76.49%) with a predominance of α-pinene (17.57%) and limonene (46.11%). Four gall morphotypes were found associated with this species. The present study reports for the first time information on the volatile constituents and the resinous potential of P. aracouchini, and registers the morphotypes of the galls that help in the taxonomy of the species.

scholarly journals Optimisation of Biogas Production through Variation of PH, Detention Time and Ratio of Substrate to Water for Rural Utilization

2019 ◽  
Vol 2 (1) ◽  
pp. 52-59 ◽  
Author(s):  
A G Jiya ◽  
U J Ijah ◽  
M Galadima ◽  
U G Akpan
Keyword(s):  
Rural Community ◽  
Numerical Optimization ◽  
Biogas Production ◽  
High Yield ◽  
Input Process ◽  
Domestic Waste ◽  
Detention Time ◽  
Biogas Yield ◽  
Optimal Values ◽  
Central Composite

A response surface methodology (RSM) was utilized in this study for optimisation of biogas production process. The optimal values of process parameter capable of giving a high yield of biogas were established. A biodigester of 20 liters capacity capable of producing biogas from rural household domestic waste was designed, constructed and used in the study. Its major units are the anaerobic and gas collecting units. The process parameters investigated are the pH of the substrate, detention time and ratio of substrate to water while the yield of biogas was used as performance characteristics. The experiment was based on a central composite rotatable design (CCRD). The results revealed that the highest yield of biogas was obtained from a combination of detention time of 30 days, ratio of substrate to water of 1:1 and pH of 7, while the least yield of biogas of 11 cm3 was obtained from combination of detention time of 30 days, ratio of substrate to water of 1:3 and pH of 2. Numerical optimization carried out with the goal of maximizing the biogas yield revealed optimum values of detention time of 40 days, the ratio of substrate and water used; 1:2 and pH of 6.71 for biogas of 771.77 cm3 with the desirability of 0.9850. The detention time had the highest significant effects on the yield of biogas. The results of this study provided standard input process variables capable of yielding the optimum yield of biogas for the rural community.

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