scholarly journals Exploratory study to assess the impact of chitosan /bentonite ratio on the metal removal capacity of chitosan modified bentonite clay

2016 ◽  
Vol 18 (2) ◽  
pp. 437-443 ◽  
Keyword(s):  
Physical Properties ◽  
Adsorption Capacity ◽  
Adsorption Isotherms ◽  
Exploratory Study ◽  
Metal Removal ◽  
Bentonite Clay ◽  
Settling Rate ◽  
Modified Bentonite ◽  
Removal Capacity ◽  
The Impact

<div> <p>Adsorption is one of the methods that can be used for metal removal. In this study five metals were used cadmium, chromium, lead, copper and Nickel (Cd, Cr, Pb, Cu, and Ni) over a concentration range from 0.8 to about 7 mg l<sup>-1</sup> for each metal. Adsorbents were prepared with increasing chitosan to bentonite ratio from 0 to 0.67 g chitosan/g bentonite. The study showed that adsorption of metals on plain bentonite and chitosan modified bentonite can fit well with Langmuir and Freundlich adsorption isotherms. Furthermore, the bentonite adsorption capacity will decrease with the increase of chitosan/bentonite ratio. This study concluded that bentonite is a good adsorbent. However, the applicability of bentonite as potential adsorbent may be limited by its physical properties such as slow settling rate and difficulty to use it as an adsorbent in adsorption columns. Despite the decrease of maximum theoretical adsorption capacity as a result of chitosan modification, the addition of small amount of chitosan can improve the physical characteristics of bentonite clay to be used as an adsorbent.&nbsp;</p> </div> <p>&nbsp;</p>

scholarly journals Effect of Aluminium Powder on Kaolin-Based Geopolymer Characteristic and Removal of Cu2+

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 814
Author(s):  
Nurliyana Ariffin ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Przemysław Postawa ◽  
Shayfull Zamree Abd Rahim ◽  
Mohd Remy Rozainy Mohd Arif Zainol ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Aluminium Powder ◽  
Removal Capacity ◽  
Properties And Characterization ◽  
Powder Content

This current work focuses on the synthesis of geopolymer-based adsorbent which uses kaolin as a source material, mixed with alkali solution consisting of 10 M NaOH and Na2SiO3 as well as aluminium powder as a foaming agent. The experimental range for the aluminium powder was between 0.6, 0.8, 1.0 and 1.2wt%. The structure, properties and characterization of the geopolymer were examined using X-Ray Diffraction (XRD), Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Adsorption capacity and porosity were analysed based on various percentages of aluminium powder added. The results indicate that the use of aluminium powder exhibited a better pore size distribution and higher porosity, suggesting a better heavy metal removal. The maximum adsorption capacity of Cu2+ approached approximately 98%. The findings indicate that 0.8% aluminium powder was the optimal aluminium powder content for geopolymer adsorbent. The removal efficiency was affected by pH, adsorbent dosage and contact time. The optimum removal capacity of Cu2+ was obtained at pH 6 with 1.5 g geopolymer adsorbent and 4 h contact time. Therefore, it can be concluded that the increase in porosity increases the adsorption of Cu2+.

Does kraft hardwood and softwood pulp viscosity correlate to paper properties?

TAPPI Journal ◽  
2016 ◽  
Vol 15 (10) ◽  
pp. 643-651 ◽  
Author(s):  
ROBERT J. OGLESBY ◽  
HUMPHREY J. MOYNIHAN ◽  
RICARDO B. SANTOS ◽  
ASHOK GHOSH ◽  
PETER W. HART
Keyword(s):  
Physical Properties ◽  
Strength Loss ◽  
Strength Properties ◽  
Clear Correlation ◽  
Paper Properties ◽  
Physical Strength ◽  
Pulp Viscosity ◽  
Softwood Pulp ◽  
The Impact ◽  
Related Paper

The impact of commercially prepared, fully bleached pulp viscosity variation on handsheet physical properties was evaluated at different levels of pulp refining. Hardwood pulps from the same brownstock species mix, cooking parameters, and kappa numbers were processed through two different commercial bleach plants: one with a D0(EP)D1D2 sequence and the second with an OD0(EOP)D1 sequence. Additionally, a commercial softwood (predominately Scotts pine) brownstock pulp bleached by an OD0(EP)D1D2 sequence was employed in this study. Pulps with viscosities ranging from 14 to 21 mPa∙s were refined in a Valley beater to two freeness levels, and the associated handsheet physical properties were measured in this study. Over the pulp viscosity range of 14 to 21 mPa∙s, no clear correlation was found to exist between pulp viscosity and related paper physical properties. Finally, a series of laboratory prepared bleached pulps were purposely prepared under non-ideal conditions to reduce their final viscosities to lower values. Handsheets made from these pulps were tested in their unbeaten condition for physical strength properties. Significant and rapid strength loss occurred when the measured pulp viscosity dropped below 12 mPa∙s; overall strength properties showed no correlation to viscosity above the critical 12 mPa∙s value.

Motivation for the Pastoral Profession in the Netherlands

2000 ◽  
Vol 28 (2) ◽  
pp. 109-118 ◽  
Author(s):  
Hessel J. Zondag
Keyword(s):  
The Netherlands ◽  
Exploratory Study ◽  
Pastoral Ministry ◽  
Well Being ◽  
Organizational Psychology ◽  
Expectancy Theory ◽  
Way Of Life ◽  
Item Questionnaire ◽  
The Impact ◽  
Protestant Denominations

Expectancy theory has been utilized by organizational psychology to explore the expectations and valuations of individuals in various professions. This study employs expectancy theory to clergy, investigating pastors' personal motivations, or values, for assuming pastoral ministry and the subsequent expectation that these values will be honored by their activities within the pastorate. The responses of 235 pastors from Catholic and Protestant denominations on a 24-item questionnaire devised to gauge pastoral motivation and adapted to assess pastoral expectations were factor analyzed and correlated in this exploratory study. The analysis yielded four robust factors. The first two motives found to be dominant were the pursuit of a Christian Way of Life and Anthropocentric Altruism. Anthropocentric Egoism and Theocentric Egoism, although secondary motivations, were theoretically meaningful in the understanding of pastoral motivations and expectations. The impact of expectations upon pastoral well-being and resilience against burnout is discussed.

Marital Satisfaction of Portuguese Families in Times of Social Lockdown

2021 ◽  
pp. 106648072110098
Author(s):  
Carla Sílvia Fernandes ◽  
Bruno Magalhães ◽  
Sílvia Silva ◽  
Beatriz Edra
Keyword(s):  
Marital Satisfaction ◽  
Exploratory Study ◽  
Social Economic ◽  
Future Research ◽  
Marital Relations ◽  
The Social ◽  
The Family ◽  
Convenience Sampling ◽  
Global Threat ◽  
The Impact

The COVID-19 pandemic represents a global threat and crisis situation, and its wide-reaching impact has also affected marital satisfaction. Dysfunction of the marital system puts the survival of the family unit at risk. This research aimed to determine the level of marital satisfaction of Portuguese families during the social lockdown and the association between the variables under study. A descriptive, exploratory study was conducted. During the social lockdown, 276 people of Portuguese nationality and residing in Portugal were recruited using nonprobabilistic convenience sampling. Marital satisfaction in the pandemic phase showed low values that may be associated with the social, economic, and political context experienced by the pandemic situation. Future research must be carried out in order to identify, prevent, and intervene in situations of violence. In addition, future research should explore not only marital satisfaction during the current pandemic but a more systemic assessment of marital relations during crises, expanding the impact of marital satisfaction in family functioning.

scholarly journals Comparison of Osmotic Resistance, Shape and Transmembrane Potential of Erythrocytes Collected from Healthy and Fed with High Fat-Carbohydrates Diet (HF-CD) Pigs—Protective Effect of Cistus incanus L. Extracts

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1050
Author(s):  
Sylwia Cyboran-Mikołajczyk ◽  
Robert Pasławski ◽  
Urszula Pasławska ◽  
Kacper Nowak ◽  
Michał Płóciennik ◽  
...  
Keyword(s):  
Biological Activity ◽  
Physical Properties ◽  
Plasma Lipid ◽  
Membrane Lipid ◽  
Osmotic Resistance ◽  
High Fat ◽  
Atherosclerotic Lesions ◽  
Cistus Incanus ◽  
Osmotic Resistance Of Erythrocytes ◽  
The Impact

Long-term high fat-carbohydrates diet (HF-CD) contributes to the formation of irreversible changes in the organism that lead to the emergence of civilization diseases. In this study, the impact of three-month high-fat diet on the physical properties of erythrocytes (RBCs) was studied. Furthermore, the biological activity of Cistus incanus L. extracts, plant known with high pro-health potential, in relation to normal and HF-CD RBCs, was determined. Obtained results have shown that, applied HF-CD modified shape, membrane potential and osmotic resistance of erythrocytes causing changes in membrane lipid composition and the distribution of lipids. The impact of HF-CD on physical properties of RBCs along with atherosclerotic lesions of the artery was visible, despite the lack of statistically significant changes in blood morphology and plasma lipid profile. This suggests that erythrocytes may be good markers of obesity-related diseases. The studies of biological activity of Cistus incanus L. extracts have demonstrated that they may ameliorate the effect of HF-CD on erythrocytes through the membrane-modifying and antioxidant activity.

scholarly journals Single Crystal Growth and Physical Properties of Pyroxene CoGeO3

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 378
Author(s):  
Li Zhao ◽  
Zhiwei Hu ◽  
Hanjie Guo ◽  
Christoph Geibel ◽  
Hong-Ji Lin ◽  
...  
Keyword(s):  
High Pressure ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Crystal Growth ◽  
Physical Properties ◽  
Single Crystal ◽  
Single Crystals ◽  
Magnetic Moments ◽  
Single Crystal Growth ◽  
The Impact

We report on the synthesis and physical properties of cm-sized CoGeO3 single crystals grown in a high pressure mirror furnace at pressures of 80 bar. Direction dependent magnetic susceptibility measurements on our single crystals reveal highly anisotropic magnetic properties that we attribute to the impact of strong single ion anisotropy appearing in this system with TN∼33.5 K. Furthermore, we observe effective magnetic moments that are exceeding the spin only values of the Co ions, which reveals the presence of sizable orbital moments in CoGeO3.

scholarly journals Cr (III) Removal Capacity in Aqueous Solution in Relation to the Functional Groups Present in the Orange Peel (Citrus sinensis)

2021 ◽  
Vol 11 (14) ◽  
pp. 6346
Author(s):  
Laura Patiño-Saldivar ◽  
José A. Hernández ◽  
Alba Ardila ◽  
Mercedes Salazar-Hernández ◽  
Alfonso Talavera ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Functional Groups ◽  
Orange Peel ◽  
Pollutant Removal ◽  
External Mass Transfer ◽  
Equilibrium Studies ◽  
Removal Capacity ◽  
Point Analysis ◽  
Agroindustrial Waste ◽  
Previously Treated

Bioremediation is a pollutant removal method that has had a great boom due to the diversity of agroindustrial waste that can be used for this purpose, and that has shown having great efficiency and profitability in the adsorption of heavy metals, such as Pb, Cu, and Co. Based on the above, the present work carried out kinetic and equilibrium studies of bioadsorption of Cr (III) using orange peel (OP) as adsorbent, previously treated with methanol, water, and a water–methanol mixture at different pH (0.91, 1.78 and 2.72), and at 30 °C, finding that the adsorption capacity at equilibrium increases with increasing pH, having a maximum of 55 mg g−1 at pH 2.72—under these conditions, lower adsorption energy was used to remove Cr (III). In addition, it was determined that there are no external mass transfer limitations. An isoelectric point analysis indicated that the adsorption is not carried out by electrostatic forces and a FTIR study of the functional groups of OP showed a decrease in the main functional groups (pectin, cellulose, and lignin, among others), which is directly related to the adsorption capacity of the bioadsorbent.

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