Enhancement of flaky graphite cleaning by ultrasonic treatment

In this study, the aim is to simplify the graphite cleaning process. In order to achieve flotation for graphite effectively, ultrasonic treatment was used as a pre-treatment technique. Flotation tests were conducted using different ultrasound power and ultrasonic treatment time. The influences of ultrasonic treatment on particle sizes, morphologies, wettability, the content of surface elements and on the flotation effect of flaky graphite were investigated. The results of ultrasonic treatment for graphite flotation were compared with the results of conventional flotation. The results showed that ultrasonic treatment not only changed the size of flaky graphite, but also eliminated impurities on the graphite surface. Additionally, the ultrasonic treatment improved the hydrophobicity of graphite. It was observed that ultrasound can remove not only silicate impurities but also most other metal impurities. The yield, carbon content and recovery of flotation concentrate were 91.46%, 95.17% and 96.12% after ultrasonic treatment for 4 min with ultrasound power 1600 W, which were 5.83%, 2.86% and 8.84% higher than that of conventional flotation, respectively. The graphite after ultrasonic treatment was conducted only one times flotation, the carbon content in concentrate products had reached 95%. This study indicates that intensifying graphite flotation by ultrasonic treatment can shorten the graphite cleaning process.

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Investigation of Dye Removal Capability of Blast Furnace Slag in Wastewater Treatment

Sustainability ◽

10.3390/su13041970 ◽

2021 ◽

Vol 13 (4) ◽

pp. 1970

Author(s):

Sara Yasipourtehrani ◽

Vladimir Strezov ◽

Tao Kan ◽

Tim Evans

Keyword(s):

Blast Furnace ◽

Blast Furnace Slag ◽

Industrial Wastewater ◽

Dye Removal ◽

Treatment Time ◽

Activated Carbons ◽

Industrial Applications ◽

Ore Processing ◽

Pre Treatment ◽

Furnace Slag

Blast Furnace Slag (BFS) is a by-product of the iron ore processing industry with potential to be used in different industrial applications. In this research, BFS was used to examine its ability for dye removal from wastewater. The efficiency of two types of BFS samples for removal of cationic methylene blue (MB) and acidic methyl orange (MO) dyes was investigated and results found that the optimal conditions for treatment of wastewater were 80 g/L of adsorbent dose and 1 h of treatment time for both dyes. BFS was found to be more effective for removal of the acidic MO dye than the cationic MB dye. Under shorter residence times, the results showed reverse trends with BFS samples removing higher concentrations of MB than MO. The BFS chemistry had additional impacts on the efficiency of dye removal. Higher basicity of BFS had lower dye removal ability for adsorption of acidic dye when applied at smaller concentrations, while for cationic dye when applied at higher concentrations. The results showed that BFS has potential role for pre-treatment of industrial wastewater contaminated with dyes and may contribute to reduced use of more expensive adsorbents, such as activated carbons.

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The Systematic Development of Attributes And Levels For A Discrete Choice Experiment of HIV Patient Preferences For Long-Acting Antiretroviral Therapies In The United States

10.21203/rs.3.rs-719332/v1 ◽

2021 ◽

Author(s):

Aaron T. Brah ◽

Douglas Barthold ◽

Brett Hauber ◽

Ann C. Collier ◽

Rodney J.Y. Ho ◽

...

Keyword(s):

Discrete Choice Experiment ◽

Discrete Choice ◽

Patient Preferences ◽

Choice Experiment ◽

Treatment Time ◽

Negative Reaction ◽

Antiretroviral Therapies ◽

Key Informant ◽

Pre Treatment ◽

Long Acting

Abstract Introduction: Patient preferences for long-acting antiretroviral therapies (LA-ART) should inform development of regimens with optimal adherence and acceptability. We describe a systematic process used to identify attributes and levels for a discrete choice experiment (DCE) designed to elicit preferences for potential LA-ART options in the US. Methods: Our approach was conducted in four stages: data collection, data reduction, removing inappropriate attributes, and optimizing wording. We started with 8 attributes defining potential LA-ART products based on existing literature and knowledge of products in development. We conducted 12 key informant interviews with experts in HIV treatment. The list of attributes, the set of plausible levels for each attribute, and restrictions on combinations of attribute levels were updated iteratively.Results: Despite uncertainty about which products will become available, key informant discussions converged on 4 delivery modes (infusions and patches were not considered immediately feasible) and 6 additional attributes. Treatment effectiveness and frequency of clinical monitoring were dropped. Oral lead-in therapy was split into two attributes: pre-treatment time undetectable and pre-treatment negative reaction testing. We omitted product-specific systemic and local side effects. In addition to mode, the final set of attributes included: frequency of dosing; location of treatment; pain; pre-treatment time undetectable; pre-treatment negative reaction testing; and late-dose leeway.Conclusions: A systematic process successfully captured elements that are both feasible and relevant to evaluating the acceptability of potential LA-ART alternatives to patients.

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Relationship between Color CIEL∗a∗b∗ and Total Organic Carbon in Compost

Advances in Materials Science and Engineering ◽

10.1155/2018/5474239 ◽

2018 ◽

Vol 2018 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Jhon Jairo Palechor-Tróchez ◽

Luis Eduardo Ordoñez Santos ◽

Hector Samuel Villada-Castillo

Keyword(s):

Organic Carbon ◽

Total Organic Carbon ◽

Carbon Content ◽

Total Organic Carbon Content ◽

Organic Carbon Content ◽

Particle Sizes ◽

Surface Color ◽

Total Organic Carbon Concentration ◽

Organic Carbon Concentration ◽

Pearson Correlations

The CIEL∗a∗b∗ coordinates and the total organic carbon content in compost were correlated. Two particle sizes of 0.5 and 2 mm were obtained in the compost samples; the surface color was analyzed with a CIEL∗a∗b∗ colorimeter and the total organic carbon content by spectrophotometry at 588.9 nm. The results indicate that all chromaticity values were significantly affected (p<0.001) by particle size. Chromaticity values a∗, b∗, C∗, and h° showed significantly strong Pearson correlations (r>0.95). The coordinates a∗ (r=−0.992) and b∗ (r=0.968) have the potential to be used in estimating the total organic carbon concentration in the compost samples analyzed.

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The Use of Heap Bioleaching as a Pre-Treatment for Platinum Group Metal Leaching

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.262.151 ◽

2017 ◽

Vol 262 ◽

pp. 151-154

Author(s):

James M. Mwase ◽

Jochen Petersen

Keyword(s):

Platinum Group Metal ◽

Metal Leaching ◽

Flotation Concentrate ◽

Group Metal ◽

Two Samples ◽

Heap Bioleaching ◽

Mineral Recovery ◽

The Difference ◽

Pre Treatment

Two samples, a Platreef flotation concentrate and coarse ore (<6 mm), were column bioleached at 65°C using a culture dominated by Metallosphaera hakonensis. Based on solution assays, extractions in excess of 90% Cu and Ni were achieved from the flotation concentrate, while from the coarse ore 96% Cu and 67% Ni extractions were achieved. The difference in extraction levels and leaching patterns despite identical conditions used for both samples is discussed, as is the performance of the samples during a follow-up leach step using cyanide to extract the PGMs in a separate column leach experiment. While the recovery of Pd and Au was excellent during these steps, recovery of Pt was limited to 35% after 45 days for the concentrate and 56% after 60 days for the whole ore material, primarily due to the presence of a refractory Pt mineral. Recovery from a concentrate without pre-treatment was substantially lower.

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The Optimization of Thermal Pre-Treatment Time for Extracellular Polymeric Substances Extraction from Sewage Sludge

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.768.496 ◽

2015 ◽

Vol 768 ◽

pp. 496-505 ◽

Cited By ~ 2

Author(s):

Yu Yi Zheng ◽

Hong Lin ◽

Zhi Long Lin ◽

Yi Fang Zeng ◽

Yu Fang Yu ◽

...

Keyword(s):

Experimental Data ◽

Sewage Sludge ◽

Process Model ◽

Extracellular Polymeric Substances ◽

Treatment Time ◽

Soluble Sugar ◽

Analytic Hierarchy ◽

Pre Treatment ◽

Hierarchy Process ◽

Optimum Extraction

This study aims to find out the optimum extraction time varied from 5 min to 60 min for extracellular polymeric substances (EPS) from sewage sludge pretreated at 80 °C. The change of the contents of EPS and its components under different time limit were recorded and compared. The results showed: the contents of soluble protein, TOC, soluble sugar and DNA was increased by 579.17 mg/l, 514.25 mg/l, 132.79 mg/l, and 34.69 mg/l, respectively, with the increase of thermal pre-treatment time during the process, and the DNA content increased the least, which indicating that the effect of thermal pre-treatment at 80 °C on cell lysis of sewage sludge was small. The EPS content, as a whole, was increased with the increase of thermal pre-treatment time. By analyzing the experimental data with the Analytic Hierarchy Process Model, which was used to identify the optimum thermal pre-treatment time of extracting EPS, the results showed that the effectiveness of EPS extraction from sludges was 30 min>60 min>50 min>20 min>40 min>10 min>5 min. Therefore, the 30 min was choosed as the optimum thermal pre-treatment time.

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Abstract 11: Comparison Of Various Methods Of Assessment Of Intracranial Collaterals On The Pretreatment Ct-angiograms To Predict Outcomes In Acute Anterior Circulation Ischemic Stroke

Stroke ◽

10.1161/str.44.suppl_1.a11 ◽

2013 ◽

Vol 44 (suppl_1) ◽

Author(s):

leonard L yeo ◽

benjamin wakerley ◽

Aftab Ahmad ◽

prakash Paliwal ◽

kay ng ◽

...

Keyword(s):

Ischemic Stroke ◽

Functional Outcome ◽

Functional Outcomes ◽

Treatment Time ◽

Scoring Systems ◽

Anterior Circulation ◽

Unaffected Side ◽

Computed Tomographic ◽

Pre Treatment ◽

Iv Tpa

Background: The presence of effective collateral blood flow patterns may influence response to intravenously administered tissue plasminogen activator (IV-tPA) in acute ischemic stroke (AIS). We compared various existing methods of scoring collaterals on the pre-treatment computed tomographic angiogram (CTA) of the brain for a reliable prediction of functional outcome in AIS patients. Methods: Consecutive AIS patients treated with IV-tPA within 4.5 hours of symptom-onset during 2007-2011 were included. Data were collected for demographics, vascular risk factors, National Institute of Health Stroke Scale (NIHSS) scores and stroke subtypes. Intracranial collaterals were evaluated by 2 independent blinded neuroradiologists via 4 predefined criteria- Miteff’s system that grades middle cerebral artery (MCA) collateral branches with respect to the sylvian fissure; Maas system that compares collaterals on the affected hemisphere against the unaffected side; modified Tan’s scale where collaterals in 50% or more of the MCA territory are classified as good; and a 20-point collateral grading scale in regions corresponding to Alberta Stroke Program Early CT score (ASPECTS) methodology. Good functional outcomes at 3-months were determined by modified Rankin scale (mRS) scores of 0-1. Results: CTA was performed in 115 patients with anterior circulation AIS before IV-tPA bolus. Median age 66yrs (range 35-92), 42% males, median NIHSS 19 points (range 3-30) and median onset-to-treatment time 155 minutes. Overall, 52 (45.2%) patients achieved good functional outcome at 3-months. Univariable analysis revealed younger age, absence of diabetes, lower pre-tPA NIHSS scores and good collaterals according to ASPECTS methodology as significantly associated with good functional outcomes. On multivariable logistic regression, only lower NIHSS (OR 1.111 per NIHSS point; 95% CI 1.023-1.206, p=0.013) and good collaterals by ASPECTS methodology (OR 1.117 per point; 95%CI 1.006-1.241, p=0.039) were found as independent predictors of good outcomes. Conclusion: Of the existing intracranial collaterals scoring systems, only the ASPECTS methodology serves as a reliable predictor of favorable outcomes at 3-months in patients with anterior circulation AIS.

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Nutrient concentration in sediments accumulated in pre-treatment basins of urban LID technologies

Water Science & Technology ◽

10.2166/wst.2019.033 ◽

2019 ◽

Vol 79 (5) ◽

pp. 1000-1006 ◽

Cited By ~ 2

Author(s):

F. K. F. Geronimo ◽

M. C. Maniquiz-Redillas ◽

J. S. Hong ◽

L. H. Kim

Keyword(s):

Low Impact Development ◽

Limiting Factor ◽

Particle Sizes ◽

Storm Events ◽

Nutrient Reduction ◽

Sediment Retention ◽

The Difference ◽

Pre Treatment ◽

Sand And Gravel

Abstract In this study, the contribution of pre-treatment basins of low impact development (LID) technologies to nutrient reduction performance was evaluated by understanding the distribution of nutrient in sediments accumulated in each system. The captured sediments were mostly silt to medium sand ranging from 9% to 92% of the sediments collected. Greater average N and P concentrations were found in silt particles amounting to 345 mg/kg and 696 mg/kg, respectively compared to sand and gravel. Although, N concentrations in accumulated sediments were found to be highly variable at different particle sizes (CV: 0.24 to 0.77) compared to P concentration (CV: 0.08 to 0.36) attributed to effective P treatment mechanism through deposition compared to complex nitrogen removal mechanisms. In addition, the difference between N and P concentrations of sediments collected in the pre-treatment basins of LID technologies and in-situ soil was attributed to the continuous pollutant input to the LID technologies during storm events. The study proved that pre-treatment basins of stormwater LID technologies reinforced the nutrient removal performances through sediment retention. The findings of this research may be used to design pre-treatment basins of LID technologies considering nutrients as a limiting factor.

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Recycle of Spent Potlining with Low Carbon Grade by Floatation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.881-883.1660 ◽

2014 ◽

Vol 881-883 ◽

pp. 1660-1664 ◽

Cited By ~ 13

Author(s):

Nan Li ◽

Gang Xie ◽

Zu Xu Wang ◽

Yan Qing Hou ◽

Rong Xing Li

Keyword(s):

Carbon Content ◽

Solid Waste ◽

Agitation Speed ◽

Pulp Density ◽

Particle Sizes ◽

Comparative Experiment ◽

Low Carbon ◽

Carbon Product ◽

Optimized Conditions

Spent potlining (SPL) from Hall-Heroult cells is a kind of toxic solid waste with recyclable carbon and electrolyte. The recycle of SPL by floatation, which can meet environment requirements and bring economic profits, is focused on presently because of its great potential to be industrialized and spread. However, it is difficult to get a good floatation index in floatation of SPL with carbon content lower than 50%. Therefore, the dressing of SPL with 36.1% of carbon has been investigated in the paper with the interesting potential to improve the quality of floatation products by optimizing floatation conditions, such as grinding size, pulp density and agitation speed of floatation machine. And the comparative experiment has been performed. The results show that quality of both carbon product and electrolyte product were improved under optimized conditions of grinding size of 90% of the particle sizes less than 0.74mm, pulp density of 25% and agitation speed of 1700r/min. The carbon content in carbon product was raised by 5.40 and carbon content in electrolyte product decreased by 0.26 while electrolyte recovery of electrolyte product increased by 4.58.

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Effects of Process Parameters on the Particle Size Distribution of Graphene Oxide Aqueous Dispersion

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.750-752.1113 ◽

2013 ◽

Vol 750-752 ◽

pp. 1113-1116 ◽

Cited By ~ 1

Author(s):

Xue Bing Hu ◽

Yun Yu ◽

Jian Er Zhou ◽

Li Xin Song

Keyword(s):

Particle Size ◽

Graphene Oxide ◽

Particle Size Distribution ◽

Size Distribution ◽

Ultrasonic Treatment ◽

Treatment Time ◽

Aqueous Dispersion ◽

Centrifugal Separation ◽

Effective Particle Size ◽

Effective Particle

During graphene oxide separation process, the effects of the process parameters such as centrifugal separation time and ultrasonic treatment time on the particle size distribution of graphene oxide aqueous dispersion were studied. The results show graphene oxide has the narrower particle size distribution and the smaller nominal effective particle size with increasing the centrifugal separation time from 20 min to 160 min. And there is a critical time in the ultrasonic treatment to obtain the narrower particle size distribution and smaller nominal effective particle size of graphene oxide. Graphene oxide has the narrower particle size distribution and the smaller nominal effective particle size when the ultrasonic treatment time is 4 h.

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