scholarly journals The ionic strength effect on microcystin and natural organic matter surrogate adsorption onto PAC

2006 ◽  
Vol 299 (2) ◽  
pp. 520-529 ◽  
Author(s):  
Margarida Campinas ◽  
Maria João Rosa
Keyword(s):  
Organic Matter ◽  
Ionic Strength ◽  
Natural Organic Matter ◽  
Ionic Strength Effect ◽  
Strength Effect

Decolorisation of natural organic matter by Phanerochaete chrysosporium: the effect of environmental conditions

2004 ◽  
Vol 4 (4) ◽  
pp. 175-182 ◽  
Author(s):  
K. Rojek ◽  
F.A. Roddick ◽  
A. Parkinson
Keyword(s):  
Organic Matter ◽  
Ionic Strength ◽  
Natural Organic Matter ◽  
Phanerochaete Chrysosporium ◽  
Fungal Growth ◽  
Low Ph ◽  
Colour Removal ◽  
Humic Material ◽  
Carbon And Nitrogen ◽  
Carbon And Nitrogen Content

Phanerochaete chrysosporium was shown to rapidly decolorise a solution of natural organic matter (NOM). The effect of various parameters such as carbon and nitrogen content, pH, ionic strength, NOM concentration and addition of Mn2+ on the colour removal process was investigated. The rapid decolorisation was related to fungal growth and biosorption rather than biodegradation as neither carbon nor nitrogen limitation, nor Mn2+ addition, triggered the decolorisation process. Low pH (pH 3) and increased ionic strength (up to 50 g L‒1 added NaCl) led to greater specific removal (NOM/unit biomass), probably due to increased electrostatic bonding between the humic material and the biomass. Adsorption of NOM with viable and inactivated (autoclaved or by sodium azide) fungal pellets occurred within 24 hours and the colour removal depended on the viability, method of inactivation and pH. Colour removal by viable pellets was higher under the same conditions, and this, combined with desorption data, confirmed that fungal metabolic activity was important in the decolorisation process. Overall, removals of up to 40–50% NOM from solution were obtained. Of this, removal by adsorption was estimated as 60–70%, half of which was physicochemical, the other half metabolically-dependent biosorption and bioaccumulation. The remainder was considered to be removed by biodegradation, although some of this may be ascribed to bioaccumulation and metabolically-dependent biosorption.

Biosorption-mediated reduction of Cr(VI) using heterotrophically-grown Chlorella vulgaris: Active sites and ionic strength effect

2013 ◽  
Vol 231 ◽  
pp. 94-102 ◽  
Author(s):  
Francesca Pagnanelli ◽  
Nohman Jbari ◽  
Franco Trabucco ◽  
Ma Eugenia Martínez ◽  
Sebastián Sánchez ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Chlorella Vulgaris ◽  
Active Sites ◽  
Ionic Strength Effect ◽  
Mediated Reduction ◽  
Strength Effect

Transport characterizations of natural organic matter in ion-exchange membrane for water treatment

2002 ◽  
Vol 2 (5-6) ◽  
pp. 445-450 ◽  
Author(s):  
D.H. Kim ◽  
S.-H. Moon ◽  
J. Cho
Keyword(s):  
Organic Matter ◽  
Ionic Strength ◽  
Ion Exchange ◽  
Natural Organic Matter ◽  
Membrane Surface ◽  
Factors Affecting ◽  
Organic Fouling ◽  
Adsorbed Mass ◽  
Pass Through ◽  
Exchange Membrane

A series of adsorption experiments were performed to investigate the factors affecting the transport of natural organic matter (NOM) in an ion-exchange (IX) membrane. In this study, the structure of the NOM was hypothesized to be an important factor in terms of the organic fouling of IX membrane. It was found that the adsorbed mass of hydrophobic NOM constituent on the membrane surface was higher than that of either the hydrophilic or transphilic NOM constituent. NOM adsorption was seriously affected by the apparent charge of the NOM. As the apparent charge increased, NOM adsorption also significantly increased. Moreover, the molecular mass of the hydrophobic NOM acids was too high to enable them to pass through the IX membrane, and this caused an accumulated adsorption of solutes on the membrane surface, i.e. NOM fouling. In addition, both pH and ionic strength affected NOM adsorption on the surface of the IX membrane. Lower NOM adsorption resulted from a lower pH and a higher ionic strength.

Ionic Strength Effect Alters the Heterogeneous Ozone Oxidation of Methoxyphenols in Going from Cloud Droplets to Aerosol Deliquescent Particles

2020 ◽  
Vol 54 (20) ◽  
pp. 12898-12907 ◽  
Author(s):  
Majda Mekic ◽  
Yiqun Wang ◽  
Gwendal Loisel ◽  
Davide Vione ◽  
Sasho Gligorovski
Keyword(s):  
Ionic Strength ◽  
Cloud Droplets ◽  
Ozone Oxidation ◽  
Ionic Strength Effect ◽  
Strength Effect

scholarly journals The role of bivalent ions in the inactivation of bacteriophage ϕ X174 by lipopolysaccharide from Escherichia coli C

1984 ◽  
Vol 223 (1) ◽  
pp. 23-29 ◽  
Author(s):  
E Rowatt
Keyword(s):  
Escherichia Coli ◽  
Ionic Strength ◽  
Electrostatic Repulsion ◽  
Square Root ◽  
Low Concentration ◽  
Ionic Strength Effect ◽  
Bivalent Ions ◽  
Order Of Magnitude ◽  
Strength Effect

The need for Ca2+ in the inactivation of bacteriophage phi X174 by lipopolysaccharide from Escherichia coli C was confirmed. Ca2+ could be replaced almost completely by Na+, but the concentration of Na+ needed was greater by more than an order of magnitude. Other bivalent ions caused inactivation in the same way as Ca2+, and the degree of inactivation varied according to the ion. At 50% inactivation of bacteriophage, the relation between the concentrations of NaCl and of bivalent or tervalent ions (Mx+) fitted the conception that NaCl was neutralizing electrostatic repulsion between virus and lipopolysaccharide by an ionic-strength effect: that is, log[Mx+] varies inversely with square root[NaCl]. The variation in effect of bi- and ter-valent ions and the low concentration needed show that this is not an ionic-strength effect but likely to involve binding to more than one site.

scholarly journals Amine-based Carbon Dioxide Absorption: The Ionic Strength Effect on the Monoethanolamine Protonation Constant at Temperatures from 313 to 333K

2020 ◽  
Vol 19 (2) ◽  
pp. 83
Author(s):  
Sholeh Ma'mun ◽  
Panji Kumala Setiawan ◽  
Egip Indrayanto
Keyword(s):  
Carbon Dioxide ◽  
Ionic Strength ◽  
Protonation Constant ◽  
Acid Dissociation ◽  
Reactive System ◽  
Co2 Removal ◽  
Co2 Absorption ◽  
Pka Values ◽  
Ionic Strength Effect ◽  
Strength Effect

Amine-based absorption has been extensively used for carbon dioxide (CO2) removal processes, such as CO2 absorption from flue gas as well as from natural gas. As a reactive system in which the chemical reaction, as well as mass transfer, occur simultaneously, an experimental determination of equilibrium reaction constants, e.g. acid dissociation/protonation constant (Ka), is, therefore, necessary to be conducted. This study aims to evaluate the ionic strength effect from 0.06 to 6.0 m (mol/kg water) on the Ka value of monoethanolamine (MEA) at temperatures between 313 and 333K. The experimental results indicate that the pKa values tend to be increasing as the ionic strength increases. This is contradicting to the temperature effect where the pKa values tend to be decreasing as the temperature increases. Furthermore, the extended Debye-Hückel formulation was implemented to predict the species activity coefficients.

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