Comparative analysis of biological versus chemical synthesis of palladium nanoparticles for catalysis of chromium (VI) reduction

AbstractThe discharge of hexavalent chromium [Cr(VI)] from several anthropogenic activities leads to environmental pollution. In this study, we explore a simple yet cost effective method for the synthesis of palladium (Pd) nanoparticles for the treatment of Cr(VI). The presence of elemental Pd [Pd(0)] was confirmed by scanning electron microscope (SEM), electron dispersive spectroscopy and X-ray diffraction (XRD). We show here that the biologically synthesized nanoparticles (Bio-PdNPs) exhibit improved catalytic reduction of Cr(VI) due to their size being smaller and also being highly dispersed as compared to chemically synthesized nanoparticles (Chem-PdNPs). The Langmuir–Hinshelwood mechanism was successfully used to model the kinetics. Using this model, the Bio-PdNPs were shown to perform better than Chem-PdNPs due to the rate constant (kbio = 6.37 mmol s−1 m−2) and Cr(VI) adsorption constant (KCr(VI),bio = 3.11 × 10−2 L mmol−1) of Bio-PdNPs being higher than the rate constant (kchem = 3.83 mmol s−1 m−2) and Cr(VI) adsorption constant (KCr(VI),chem = 1.14 × 10−2 L mmol−1) of Chem-PdNPs. In addition, product inhibition by trivalent chromium [Cr(III)] was high in Chem-PdNPs as indicated by the high adsorption constant of Cr(III) in Chem-PdNPs of KCr(III),chem = 52.9 L mmol−1 as compared to the one for Bio-PdNPs of KCr(III),bio = 2.76 L mmol−1.

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Sprouting of Sorghum (Sorghum bicolor [L.] Moench): Effect of Drying Treatment on Protein and Starch Features

Foods ◽

10.3390/foods10020407 ◽

2021 ◽

Vol 10 (2) ◽

pp. 407 ◽

Cited By ~ 1

Author(s):

Mia Marchini ◽

Alessandra Marti ◽

Claudia Folli ◽

Barbara Prandi ◽

Tommaso Ganino ◽

...

Keyword(s):

Food Production ◽

Cost Effective ◽

High Exposure ◽

Effective Technology ◽

Drying Treatment ◽

Higher Temperature ◽

Lower Temperature ◽

The One ◽

Drying Conditions ◽

Sorghum Bicolor L

The nutritional and physicochemical properties of sorghum proteins and starch make the use of this cereal for food production challenging. Sprouting is a cost-effective technology to improve the nutritional and functional profile of grains. Two drying treatments were used after sorghum sprouting to investigate whether the drying phase could improve the protein and starch functionalities. Results showed that the drying treatment at lower temperature/longer time (40 °C for 12 h) extended the enzymatic activity that started during sprouting compared to the one performed at higher temperature/shorter time (50 °C for 6 h). An increased protein hydrolysis and water- and oil-holding capacity were found in the flour obtained by the former treatment. Higher protein matrix hydrolysis caused high exposure of starch to enzymes, thus increasing its digestibility, while worsening the technological functionality. Overall, modulating drying conditions could represent a further way, in addition to sprouting, to improve sorghum flour’s nutritional profile.

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Rapid Degradation of Carbon Tetrachloride by Microscale Ag/Fe Bimetallic Particles

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18042124 ◽

2021 ◽

Vol 18 (4) ◽

pp. 2124

Author(s):

Xueqiang Zhu ◽

Lai Zhou ◽

Yuncong Li ◽

Baoping Han ◽

Qiyan Feng

Keyword(s):

Humic Acid ◽

Catalytic Reduction ◽

Direct Reduction ◽

Cost Effective ◽

Degradation Efficiency ◽

Pseudo First Order Reaction ◽

Solution Ph ◽

Reaction Stage ◽

Bimetallic Particles ◽

Slow Reaction

Cost-effective zero valent iron (ZVI)-based bimetallic particles are a novel and promising technology for contaminant removal. The objective of this study was to evaluate the effectiveness of CCl4 removal from aqueous solution using microscale Ag/Fe bimetallic particles which were prepared by depositing Ag on millimeter-scale sponge ZVI particles. Kinetics of CCl4 degradation, the effect of Ag loading, the Ag/Fe dosage, initial solution pH, and humic acid on degradation efficiency were investigated. Ag deposited on ZVI promoted the CCl4 degradation efficiency and rate. The CCl4 degradation resulted from the indirect catalytic reduction of absorbed atomic hydrogen and the direct reduction on the ZVI surface. The CCl4 degradation by Ag/Fe particles was divided into slow reaction stage and accelerated reaction stage, and both stages were in accordance with the pseudo-first-order reaction kinetics. The degradation rate of CCl4 in the accelerated reaction stage was 2.29–5.57-fold faster than that in the slow reaction stage. The maximum degradation efficiency was obtained for 0.2 wt.% Ag loading. The degradation efficiency increased with increasing Ag/Fe dosage. The optimal pH for CCl4 degradation by Ag/Fe was about 6. The presence of humic acid had an adverse effect on CCl4 removal.

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Exploiting the Potential in Water Cleanup from Metals and Nutrients of Desmodesmus sp. and Ampelodesmos mauritanicus

Plants ◽

10.3390/plants10071461 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1461

Author(s):

Roberto Braglia ◽

Lorenza Rugnini ◽

Sara Malizia ◽

Francesco Scuderi ◽

Enrico Luigi Redi ◽

...

Keyword(s):

Heavy Metals ◽

Metal Removal ◽

Anthropogenic Activities ◽

Cost Effective ◽

Single Species ◽

Nitrogen And Phosphorus ◽

Removal Rates ◽

Sequential Approach ◽

Removal Capacity ◽

Green Microalga

Increasing levels of freshwater contaminants, mainly due to anthropogenic activities, have resulted in a great deal of interest in finding new eco-friendly, cost-effective and efficient methods for remediating polluted waters. The aim of this work was to assess the feasibility of using a green microalga Desmodesmus sp., a cyanobacterium Nostoc sp. and a hemicryptophyte Ampelodesmos mauritanicus to bioremediate a water polluted with an excess of nutrients (nitrogen and phosphorus) and heavy metals (copper and nickel). We immediately determined that Nostoc sp. was sensitive to metal toxicity, and thus Desmodesmus sp. was chosen for sequential tests with A. mauritanicus. First, A. mauritanicus plants were grown in the ‘polluted’ culture medium for seven days and were, then, substituted by Desmodesmus sp. for a further seven days (14 days in total). Heavy metals were shown to negatively affect both the growth rates and nutrient removal capacity. The sequential approach resulted in high metal removal rates in the single metal solutions up to 74% for Cu and 85% for Ni, while, in the bi-metal solutions, the removal rates were lower and showed a bias for Cu uptake. Single species controls showed better outcomes; however, further studies are necessary to investigate the behavior of new species.

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Simple and Visible Detection of Novel Astroviruses Causing Fatal Gout in Goslings Using One-Step Reverse Transcription Polymerase Spiral Reaction Method

Frontiers in Veterinary Science ◽

10.3389/fvets.2020.579432 ◽

2020 ◽

Vol 7 ◽

Author(s):

Jun Ji ◽

Qinxi Chen ◽

Zhengli Yu ◽

Xin Xu ◽

Xinhao Mu ◽

...

Keyword(s):

Reverse Transcription ◽

Cost Effective ◽

Pcr Primers ◽

Probit Regression ◽

Conventional Pcr ◽

Specific Detection ◽

Isothermal Method ◽

Naked Eye ◽

One Step ◽

The One

In this study, a one-step isothermal method combining polymerase spiral reaction (PSR) with reverse transcription (RT-PSR) was established for rapid and specific detection of novel astroviruses causing fatal gout in goslings (N-GoAstV). The one-step RT-PSR was accomplished at the optimal temperature of 62°C and time of 40 min and used primers simply designed as conventional PCR primers, and the results of detection were visible to the naked eye. The detection limit of PSR was above 34.7 copies/μL at a 95% probability level according to probit regression analysis. The assay specifically detected N-GoAstV, and no other reference viruses were detected. These results suggest that the newly established RT-PSR assay could, in one step, accomplish reverse-transcription, amplification, and result determination providing a visible, convenient, rapid, and cost-effective test that can be carried out onsite, in order to ensure timely quarantine of N-GoAstV-infected birds, leading to effective disease control.

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Aquatic environments in the One Health context: modulating the antimicrobial resistance phenomenon

Acta Limnologica Brasiliensia ◽

10.1590/s2179-975x4719 ◽

2020 ◽

Vol 32 ◽

Cited By ~ 1

Author(s):

Juliana Alves Resende ◽

Vânia Lúcia da Silva ◽

Claudio Galuppo Diniz

Keyword(s):

Antimicrobial Resistance ◽

One Health ◽

Anthropogenic Activities ◽

Treatment Strategies ◽

Chemical Pollution ◽

Resistant Bacteria ◽

Aquatic Environments ◽

Antimicrobial Substances ◽

Antimicrobial Resistance Genes ◽

The One

Abstract: From an anthropocentric perspective, aquatic environments are important to maintain health and survival, however, as they are sometimes managed based on misconception, they are considered a convergent pathway for anthropogenic residues and sanitation. Thus, it is observed that these ecosystems have been threatened by chemical pollution due to xenobiotics, especially from a more contemporary approach, by the selective pressure associated with antimicrobials. There are several studies that report the enrichment of antimicrobial resistant bacteria and mobilizable antimicrobial resistance genes in aquatic and adjacent ecosystems. From the perspective of the emerging and reemerging number of diseases related to the interplay of human, animal, and environmental factors, a new conception arose to address these issues holistically, which is known as the One Health approach. Scientific and political discourse on this conception should lead to effective action plans for preventing and controlling the spread of infectious diseases in open environment, including those impacted by anthropogenic activities. Therefore, nowadays, discussions on antimicrobial resistance are becoming broader and are requiring a multi-disciplinary view to address health and environmental challenges, which includes aquatic environment management. Water may represent one of the most important ecosystems for the in antimicrobial resistance phenomenon that arises when a dynamic and singular microbial community may be influenced by several characteristics. As antimicrobial substances do not all degrade at the same time under the same treatment, strategies concerning their removal from the environment should consider their individualized chemical characteristics.

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Metal Oxide Nanoparticles and their Nanocomposite-based Materials as Photocatalysts in the Degradation of Dyes

Biointerface Research in Applied Chemistry ◽

10.33263/briac125.65576579 ◽

2021 ◽

Vol 12 (5) ◽

pp. 6557-6579

Keyword(s):

Metal Oxide ◽

Anthropogenic Activities ◽

Metal Oxide Nanoparticles ◽

Chemical Properties ◽

Cost Effective ◽

Oxide Nanoparticles ◽

Synthetic Dyes ◽

Characterization Methods ◽

Degradation Of Dyes ◽

Physical And Chemical

The introduction of inorganic and organic pollutants into water bodies has become a serious issue globally. The waste streams released from the textile, plastic, leather, paper, pharmaceutical, and food industries introduce different natural and synthetic dyes into the aquatic system. Nanomaterials play a significant role in the photocatalytic degradation of dyes present in wastewater. Inorganic metal oxide nanoparticles have many improved physical and chemical properties and attracted much attention in photocatalytic activities. Dyes have been released in our aquatic bodies due to many anthropogenic activities and caused life-threatening problems. Various conventional methods were reported to remove dyes from water and wastewater; the photocatalytic method is one of the efficient and cost-effective. The present review article includes detailed information on photocatalysis, the potential of metal oxide and their composite materials as photocatalysts in the degradation of toxic dyes, and some common synthetic and characterization methods used for metal oxide-based nanoparticles.

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Observation of a radical intermediate in the one electron oxidation of 5-methyl-1-thia-5-azacyclooctane by •Br2−

Canadian Journal of Chemistry ◽

10.1139/v84-321 ◽

1984 ◽

Vol 62 (9) ◽

pp. 1874-1876 ◽

Cited By ~ 7

Author(s):

Warren Kenneth Musker ◽

Parminder S. Surdhar ◽

Rizwan Ahmad ◽

David A. Armstrong

Keyword(s):

Aqueous Solution ◽

Rate Constant ◽

Half Life ◽

Cation Radical ◽

Order Rate Constant ◽

Type Structure ◽

Radical Intermediate ◽

Text Type ◽

First Order ◽

The One

The one electron oxidant •Br2− reacts with 5-methyl-1-thia-5-azacyclooctane (4) in aqueous solution at high pH with an overall rate constant of ~2 × 108 M s−1. The radical intermediate produced has a broad maximum at 500 nm with ε = 2400 M−1 cm−1 and at pH 10 decays with a first order rate constant of 2.3 ± 0.3 × 104 s−1, first half-life of 30 ± 5 μs. Its characteristics do not correspond to those of the [Formula: see text] species reported by Asmus and co-workers. The species appears to be the same as the cation radical reported earlier in the one electron oxidation of 4 in acetonitrile. This species is considered to have an [Formula: see text] type structure, which provides transannular stabilization.

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A computer simulation model of forest fire suppression with air tankers

Canadian Journal of Forest Research ◽

10.1139/x79-066 ◽

1979 ◽

Vol 9 (3) ◽

pp. 390-398 ◽

Cited By ~ 5

Author(s):

A. J. Simard

Keyword(s):

Computer Simulation ◽

Simulation Model ◽

Historical Data ◽

Fire Suppression ◽

Cost Effective ◽

Computer Simulation Model ◽

Fire Dynamics ◽

Data Output ◽

The One ◽

Fire Ground

A computer simulation model which evaluates air tanker productivity and effectiveness is described. Three hundred equations are required to define the model, which consists of five components: administration, the environment, the fire, ground suppression, and air tanker utilization. AIRPRO, a computer program based on the model, tests various combinations of air tanker resources and tactics and selects the one which minimizes suppression cost plus damage caused by fire. The program contains four loops: the fire, the tactic, the event, and fire dynamics (growth and suppression). The environmental, fire, and ground suppression components were validated by comparing model output with historical data. Output of the air tanker component was examined for reasonableness, compared with previous research, and a sensitivity analysis was performed. It is concluded that an assumption of model validity is reasonable. In applying the model in New Brunswick, it was found that medium sized land-based air tankers were the most cost effective, followed by small land-based air tankers. It was also found that a fleet of three or four aircraft would be optimum.

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Better regulation, administrative sanctions and constitutional values

Legal Studies ◽

10.1111/j.1748-121x.2012.00241.x ◽

2013 ◽

Vol 33 (2) ◽

pp. 312-339

Author(s):

Karen Yeung

Keyword(s):

Due Process ◽

Cost Effective ◽

The Other ◽

Regulatory Enforcement ◽

The Rule Of Law ◽

Enforcement Action ◽

Better Regulation ◽

The One ◽

The Uk ◽

Administrative Sanctions

This paper interrogates the predisposition in favour of informal, low-intervention control styles of enforcement advocated by the ‘better regulation’ movement, and which resonates throughout the Hampton Report recommendations which are currently being implemented in the UK. It focuses on three practices that reflect the trend towards diverting regulatory enforcement action away from the courts in favour of reliance on formal administrative sanctioning powers ranging from ‘hard’ to ‘soft’: the use of negotiated penalty settlements, the acceptance of administrative undertakings (‘enforcement undertakings’) and the provision of firm-specific compliance advice by regulators. Each practice is explored through various analytical lenses which enable the underlying constitutional tensions to be identified and interrogated. In so doing, it demonstrates how the emphasis on bargaining, negotiation and discussions between regulators and those they are responsible for regulating advocated by the UK better regulation movement may antagonise several constitutional values, including transparency, accountability, due process and participation, as well as several values associated with formal conceptions of the rule of law. On the other hand, resort to negotiation and discussion in regulatory enforcement can generate important benefits, largely in facilitating the timely, creative and cost-effective resolution of enforcement disputes while avoiding the formality, delay and hostility associated with formal court adjudication. This ‘clash of logics’ can be traced to inherent differences between bargaining, on the one hand, and adjudication on the other. Bargaining and adjudication represent two quite different and distinct forms of ordering through which disputes can be resolved, and it is these differences that lie at the foundation of their respective virtues and shortcomings when employed to resolve disputes concerning regulatory violations.

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Using Google Earth™ and Geographical Information System data as method to delineate sample domains for an urban household surveys: the case of Maroua (Far North Region-Cameroon)

International Journal of Health Geographics ◽

10.1186/s12942-019-0186-8 ◽

2019 ◽

Vol 18 (1) ◽

Cited By ~ 1

Author(s):

Ronald R. B. Ngom Vougat ◽

Steven Chouto ◽

Sylvain Aoudou Doua ◽

Rebecca Garabed ◽

André Zoli Pagnah ◽

...

Keyword(s):

Low Cost ◽

Cost Effective ◽

Google Earth ◽

Geographical Information ◽

Gps Tracking ◽

Low Incomes ◽

Global Positioning ◽

System Data ◽

The One ◽

Time Required

Abstract Background Getting a random household sample during a survey can be expensive and very difficult especially in urban area and non-specialist. This study aimed to test an alternative method using freely available aerial imagery. Methods A gridded map and random selection method was used to select households for interviews. A hundred numbered of points were put along the edges of an updated map of Maroua. Then two numbers were randomly draw at a time and a line was drawn between those two numbers. A lot of different kinds of shapes of different sizes obtained were numbered. Ten shapes were randomly draw and the one selected were considered as ‘neighbourhoods’. A grid of 30 m × 30 m was drawn over each and then numbered. 202 grids considered here as households were randomly selected from the ten neighbourhoods for interviews. Results Out of 202 households visited, only 4 were found to be something other than a house. In addition, 30 sampled households (14.85%) were abandoned or the occupants had relocated elsewhere. This method resulted in an accuracy level of 72%, its advantage is the ability to generate efficient random sample at relatively low cost as well the time required. Conclusions The method proposed in this study was efficient and cost-effective when compared to the infield generation of a household inventory or Global Positioning System (GPS) tracking of households. It can then be used by researchers in low-incomes countries where funding for research is a challenge. However, this method needs to train the investigators on how to use the GPS.

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