Adsorption of Coliphages to Particulates

1986 ◽  
Vol 18 (7-8) ◽  
pp. 267-275 ◽  
Author(s):  
S. Ohgaki ◽  
A. Ketratanakul ◽  
S. Suddevgrai ◽  
U. Prasertsom ◽  
O. Suthienkul
Keyword(s):  
Natural Waters ◽  
Divalent Cations ◽  
Solid Surfaces ◽  
Water Phase ◽  
Desorption Process ◽  
Oxidation Pond ◽  
E Coli ◽  
Soil Microbial ◽  
Alkaline Conditions ◽  
Adsorption Desorption

Adsorption characteristics of coliphages (host cell: E. coli B) to particulates (kaolin, sand, soil, microbial particulates in an oxidation pond) were investigated using batch experiments under various conditions of pH, concentrations of cations and concentrations of dissolved oxygen. The coliphages showed no resistance to acid (pH 3) and weak resistance to alkali (pH 10). Under neutral pH conditions, sodium ions did not have a large effect on the adsorption of coliphages to the solid surfaces of sand. Divalent cations (Mg++, Ca++) had no effect on the adsorption to sand at concentrations below 0.01 mol/l but some effect at 0.05 and 0.1 mol/l. The presence of kaolin had very little effect on removal of coliphages from the water phase under any conditions. Formation of floes such as Mg-hydroxides in alkaline conditions enhanced coliphage removal from the water phase. Coliphage chemical adsorption to particulates in natural waters would probably be low except in estuarine and sea waters. However, the adsorption of coliphages to microbial particulates occurred in aerobic conditions. The desorption of coliphages was observed under anaerobic conditions. This adsorption-desorption process was reversible. The biological adsorption appears to be the dominating cause of coliphage adsorption in natural waters containing microbial particulates.

Effect of Sunlight on Coliphages in an Oxidation Pond

1986 ◽  
Vol 18 (10) ◽  
pp. 37-46 ◽  
Author(s):  
Shinichiro Ohgaki ◽  
Awrapin Ketratanakul ◽  
Uthaiphun Prasertsom
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Field Measurement ◽  
Host Cells ◽  
Dissolved Oxygen Concentration ◽  
High Concentration ◽  
Desorption Process ◽  
Oxidation Pond ◽  
Exposure Experiment ◽  
Adsorption Desorption

Escherichia coli B were used as host cells for isolation and multiplication of coliphages. The coliphages were isolated from a small canal which receives the effluent from an oxidation pond in Bangkok, Thailand, and were used as a virological indicator. Coliphages were assayed by the plaque forming technique (PFU method). The coliphage which was used in this study had no resistance to acid (pH3) and weak resistance to alkali (pH 10).The fate of coliphages in the oxidation pond was investigated by field measurement and laboratory experiments. Batch experiments showed the adsorption of coliphage to microbial particulates (mainly algae) occurred under aerobic conditions. The desorption of coliphage from the particulates was observed under anaerobic conditions. The adsorption-desorption process was reversible and was controlled by dissolved oxygen concentration. The same mechanism of adsorption-desorption was observed in the oxidation pond as well. During day-time, the concentration of coliphage decreased under high concentration of dissolved oxygen caused by photosynthesis. On the other hand, the concentration of coliphage increased after sunset because the dissolved oxygen concentration in the pond decreased to zero due to respiration of algae. The degree of removal of coliphage in the oxidation pond (design retention time = 20 days) was 90% (1 log). Field measurement with submerged bottles in the oxidation pond and sunlight-exposure experiment using beakers showed that coliphage could be inactivated by sunlight only near the water surface (less than 10 cm depth, the highest estimate) in the oxidation pond.

Adsorption-desorption processes on solid surfaces.

1983 ◽  
Vol 139 (4) ◽  
pp. 736
Author(s):  
V.N. Ageev ◽  
E.Ya. Zandberg ◽  
N.I. Ionov ◽  
A.Ya. Tontegode
Keyword(s):  
Solid Surfaces ◽  
Adsorption Desorption

Divalent cations speciation with three phosphonate ligands in the pH-range of natural waters

Talanta ◽  
1997 ◽  
Vol 44 (5) ◽  
pp. 897-907 ◽  
Author(s):  
Véronique Deluchat ◽  
Jean-Claude Bollinger ◽  
Bernard Serpaud ◽  
Claude Caullet
Keyword(s):  
Natural Waters ◽  
Divalent Cations ◽  
Ph Range ◽  
Phosphonate Ligands

Numerical Modelling of the Heat and Mass Transfer in a Channel with Hygroscopic Walls

2008 ◽  
Vol 273-276 ◽  
pp. 782-788 ◽  
Author(s):  
C.R. Ruivo ◽  
J.J. Costa ◽  
A.R. Figueiredo
Keyword(s):  
Mass Transfer ◽  
Porous Medium ◽  
Numerical Modelling ◽  
Heat And Mass Transfer ◽  
Sorption Isotherms ◽  
Physical Modelling ◽  
Desorption Process ◽  
Strongly Coupled ◽  
Two Phases ◽  
Adsorption Desorption

In this paper the numerical modelling of the behaviour of a channel of a hygroscopic compact matrix is presented. The heat and mass transfer phenomena occurring in the porous medium and within the airflow are strongly coupled, and some properties of the airflow and of the desiccant medium exhibit important changes during the sorption/desorption processes. The adopted physical modelling takes into account the gas side and solid side resistances to heat and mass transfer, as well as the simultaneous heat and mass transfer together with the water adsorption/desorption process in the wall domain. Two phases co-exist in equilibrium inside the desiccant porous medium, the equilibrium being characterized by sorption isotherms. The airflow is treated as a bulk flow, the interaction with the wall being evaluated by using appropriated convective coefficients. The model is used to perform simulations considering two distinct values of the channel wall thickness and different lengths of the channel. The results of the modelling lead to a good understanding of the relationship between the characteristics of the sorption processes and the behaviour of hygroscopic matrices, and provide guidelines for the wheel optimization, namely of the duration of the adsorption and desorption periods occurring in each hygroscopic channel.

The adsorption–desorption process of bovine serum albumin on carbon nanotubes

2007 ◽  
Vol 307 (2) ◽  
pp. 349-356 ◽  
Author(s):  
Laura E. Valenti ◽  
Pablo A. Fiorito ◽  
Carlos D. García ◽  
Carla E. Giacomelli
Keyword(s):  
Carbon Nanotubes ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Desorption Process ◽  
Adsorption Desorption

Tetracycline Removal Enhancement With Fe-Saturated Nanoporous Montmorillonite in a Tripartite Adsorption/Desorption/Photo-Fenton Degradation Process

2021 ◽  
Author(s):  
Shiva Chahardahmasoumi ◽  
Seyed Amir Hossein Jalali ◽  
Mehdi Nasiri Sarvi
Keyword(s):  
Antimicrobial Activity ◽  
Visible Light ◽  
Fenton Reaction ◽  
Degradation Process ◽  
Oh Radicals ◽  
Desorption Process ◽  
High Tc ◽  
Modified Montmorillonite ◽  
Adsorption Desorption ◽  
First Time

Abstract The adsorption and photo-Fenton degradation of tetracycline (TC) over Fe saturated nanoporous montmorillonite was analyzed. The synthesized samples were characterized using XRD, FTIR, SEM, and XRF analysis, and the adsorption and desorption of TC onto these samples as well as the antimicrobial activity of TC during these processes were analyzed at different pH. The results indicated that the montmorillonite is a great adsorbent for the separation of the TC from aqueous solutions, however, after increasing the amount of TC adsorbed, the desorption process started, and up to 50% of TC adsorbed onto non-modified montmorillonite was released back to the solution with almost no changes in its antimicrobial activity. After acid treatment (for creation of nanoporous layers) and Fe saturation of the montmorillonite, almost similar great separation was achieved compared to non-modified montmorillonite. In addition, the desorption of TC from modified montmorillonite was still high up to 40% of adsorbed TC. However, simultaneous adsorption and photodegradation of TC were detected and almost no antimicrobial activity was detected after 180 min of visible light irradiation, which could be due to the photo-Fenton degradation of TC on the modified montmorillonite surface. In the porous structures of modified montmorillonite high ˙OH radicals were created in the photo-Fenton reaction and were measured using the Coumarin technique. The ˙OH radicals help the degradation of TC as proposed in an oxidation process. Surprisingly, more than 90 % of antimicrobial activity of the TC decreased under visible light (after 180 min) when desorbed from nanoporous Fe-saturated montmorillonite compared to natural montmorillonite. To the best of our knowledge, this is the first time that such a high TC desorption rate from an adsorbent with the least remained antimicrobial activity is reported which makes nanoporous Fe-saturated montmorillonite a perfect separation substance of TC from the environment.

scholarly journals Using An Exponential Equation to Describe Adsorption/Desorption Processes of Water on Composite Soil at Constant Pressure

2003 ◽  
Vol 21 (4) ◽  
pp. 383-388
Author(s):  
Lianxi Ma ◽  
James C. Holste ◽  
Kenneth R. Hall
Keyword(s):  
Experimental Data ◽  
Water Vapour ◽  
Constant Pressure ◽  
Exponential Equation ◽  
Desorption Process ◽  
Experimental Time ◽  
Long Time ◽  
Experimental Values ◽  
Adsorption Desorption

Using the assumption that adsorption as a function of time may be expressed by an exponential equation, viz. ΔM = g + he−t/τ, it is possible to obtain the amount of water vapour adsorbed by a composite soil without waiting for equilibrium, which usually takes a long time. Given the experimental data for the amounts adsorbed versus time, one can determine g, h and τ, together with the amounts adsorbed at equilibrium by extrapolating the above equation to t → ∞. It is also possible to calculate the error trends in these parameters as a function of time by comparing the values at time t with those obtained for the longest experimental time. The error trends of the equation with time arise from the comparison of the experimental values with those predicted by the exponential equation. We have discovered that although different lengths of time are necessary for different pressures, generally a time between 1.5τ and 2τ is sufficient to obtain reliable results with errors less than 5%. We have also found that this equation describes the desorption process as well.

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