Biodegradation of naphthalene in montmorillonite/polyacryamide suspensions

1995 ◽  
Vol 31 (1) ◽  
pp. 85-94 ◽  
Author(s):  
S. Magdaliniuk ◽  
J. C. Block ◽  
C. Leyval ◽  
J. Y. Bottero ◽  
G. Villemin ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Mass Transfer ◽  
Aqueous Phase ◽  
Pseudomonas Cepacia ◽  
Aerobic Conditions ◽  
Naphthalene Degradation ◽  
Phase Saturation ◽  
Viable Bacteria ◽  
Adsorption Desorption ◽  
Kinetics Of

The biodegradation of naphthalene in the presence of Na montmorillonite particles, of montmorillonite/polyacrylamide complexes and of polyacrylamide alone was studied in batch assays under aerobic conditions. The concentrations of naphthalene used were below aqueous phase saturation. Adsorption-desorption experiments with montmorillonite and montmorillonite/polyacrylamides complex indicated that little or no naphthalene was adsorbed. Adsorption appeared totally reversible and desorption was rapid, reaching completion in less than 24 hours. Naphthalene was rapidly degraded by an adapted strain of Pseudomonas cepacia (10-25 hours) as a function of the initial viable bacteria count of the inoculum. The kinetics of naphthalene degradation in the presence of montmorillonite/polyacrylamide complexes or even with montmorillonite alone (with no naphthalene adsorbed), were slower (0.64 mg l−1 h−1) than in clayless aqueous solution (0.84 mg l−1 h−1). Dissolved non-biodegradable polyacrylamide had no effect on naphthalene degradation. These results indicate that particles decrease the rate of naphthalene breakdown byPseudomonas cepacia . This may be caused by the fact that montmorillonite particles are smaller on average than bacteria cells. Montmorillonite particles may cover bacteria and so limits nutrient mass transfer.

scholarly journals Different photolysis kinetics at the surface of frozen freshwater vs. frozen salt solutions

2010 ◽  
Vol 10 (5) ◽  
pp. 12063-12077
Author(s):  
T. F. Kahan ◽  
N.-O. A. Kwamena ◽  
D. J. Donaldson
Keyword(s):  
Aqueous Solution ◽  
Sodium Chloride ◽  
Organic Compound ◽  
Aqueous Phase ◽  
Physical Nature ◽  
Salt Solutions ◽  
Marked Contrast ◽  
Photolysis Rates ◽  
Halide Salts ◽  
Kinetics Of

Abstract. The presence of solutes such as sodium halide salts can greatly alter the physical nature of air-ice interfaces. In this work, we studied the effects of sodium chloride and sodium bromide on the photolysis kinetics of harmine, an aromatic organic compound, in aqueous solution and at the surface of frozen salt solutions. Harmine photolysis is much faster on pure ice surfaces than in aqueous solution, but the presence of NaCl or NaBr – which does not affect photolysis kinetics in solution – reduces the photolysis rate on ice. The rate decreases monotonically with increasing salt concentration; at the concentrations found in seawater, harmine photolysis at the surface of frozen salt solutions proceeds at the same rate as in aqueous solution. These results suggest that the brine excluded to the surfaces of frozen salt solutions is a true aqueous solution, and so it may be possible to use aqueous-phase kinetics to predict photolysis rates on sea ice. This is in marked contrast to the result at the surface of pure ice samples, where reaction kinetics are often not well-described by aqueous-phase processes.

scholarly journals Different photolysis kinetics at the surface of frozen freshwater vs. frozen salt solutions

2010 ◽  
Vol 10 (22) ◽  
pp. 10917-10922 ◽  
Author(s):  
T. F. Kahan ◽  
N.-O. A. Kwamena ◽  
D. J. Donaldson
Keyword(s):  
Aqueous Solution ◽  
Aqueous Phase ◽  
Salt Solutions ◽  
Ice Surface ◽  
Photolysis Rates ◽  
Quasi Liquid Layer ◽  
Ice Surfaces ◽  
Halide Salts ◽  
Physical And Chemical ◽  
Kinetics Of

Abstract. Reactions at air-ice interfaces can proceed at very different rates than those in aqueous solution, due to the unique disordered region at the ice surface known as the quasi-liquid layer (QLL) . The physical and chemical nature of the surfacial region of ice is greatly affected by solutes such as sodium halide salts. In this work, we studied the effects of sodium chloride and sodium bromide on the photolysis kinetics of harmine, an aromatic organic compound, in aqueous solution and at the surface of frozen salt solutions above the eutectic temperature. In common with other aromatic organic compounds we have studied, harmine photolysis is much faster on ice surfaces than in aqueous solution, but the presence of NaCl or NaBr – which does not affect photolysis kinetics in solution – reduces the photolysis rate on ice. The rate decreases monotonically with increasing salt concentration; at the concentrations found in seawater, harmine photolysis at the surface of frozen salt solutions proceeds at the same rate as in aqueous solution. These results suggest that the brine excluded to the surfaces of frozen salt solutions is a true aqueous solution, and so it may be possible to use aqueous-phase kinetics to predict photolysis rates at sea ice surfaces. This is in marked contrast to the result at the surface of frozen freshwater samples, where reaction kinetics are often not well-described by aqueous-phase processes.

Kinetics of Mass Transfer of Tryptophan between an Aqueous Phase and a Water-in-Oil Microemulsion

Langmuir ◽  
1995 ◽  
Vol 11 (12) ◽  
pp. 4691-4694 ◽  
Author(s):  
Pawel Plucinski ◽  
Walter Nitsch
Keyword(s):  
Mass Transfer ◽  
Aqueous Phase ◽  
Kinetics Of

Competition kinetics of OH radical reactions with oxygenated organic compounds in aqueous solution: rate constants and internal optical absorption effects

2018 ◽  
Vol 20 (16) ◽  
pp. 10939-10948 ◽  
Author(s):  
T. Schaefer ◽  
H. Herrmann
Keyword(s):  
Aqueous Solution ◽  
Optical Absorption ◽  
Organic Compounds ◽  
Aqueous Phase ◽  
Rate Constants ◽  
Radical Reactions ◽  
Solution Rate ◽  
Oh Radical ◽  
Kinetics Of

Atmospheric aqueous phase rate constants are determined and the effect of optical absorbers in competition kinetics is studied.

scholarly journals Mass transfer in the bath reactor of the adsorption process of 1,2-dichloropropane from aqueous solution onto the activated carbon

2007 ◽  
Vol 9 (2) ◽  
pp. 30-33
Author(s):  
Robert Pełech
Keyword(s):  
Aqueous Solution ◽  
Mass Transfer ◽  
Activated Carbon ◽  
Rate Constant ◽  
Adsorption Process ◽  
Particle Diameter ◽  
Mixing Conditions ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Order Rate Equation

Mass transfer in the bath reactor of the adsorption process of 1,2-dichloropropane from aqueous solution onto the activated carbon A pseudo-second order rate equation describing the kinetics of the adsorption of 1,2-dichloropropane from aqueous solution onto the activated carbon at different initial concentrations, adsorbent dose, temperature, particle diameter and the rate of stirring have been developed. The rate constant was calculated. The rate constant correlation in a good mixing conditions was described as a function of the temperature.

Methodology of Research in Micropollutants – Heavy Metals

1982 ◽  
Vol 14 (12) ◽  
pp. 107-125 ◽  
Author(s):  
Roland Wollast
Keyword(s):  
Heavy Metals ◽  
Mathematical Models ◽  
Aqueous Phase ◽  
Suspended Matter ◽  
Solid Phase ◽  
Aquatic Organisms ◽  
Biological Processes ◽  
Particulate Phase ◽  
Sources Of Pollution ◽  
Adsorption Desorption

A comparison of the concentration of dissolved and of particulate heavy metals in the aquatic system indicates that these elements are strongly enriched in the suspended matter. The transfer between the aqueous phase and the solid phase may be due to dissolution-precipitation reactions, adsorption-desorption processes or biological processes. When these processes are identified, it is further possible to develop mathematical models which describe the behaviour of these elements. The enrichment of heavy metals in the particulate phase suspended or deposited and in aquatic organisms constitutes a powerful tool in order to evaluate sources of pollution.

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