scholarly journals Elution Is a Critical Step for Recovering Human Adenovirus 40 from Tap Water and Surface Water by Cross-Flow Ultrafiltration

2016 ◽  
Vol 82 (16) ◽  
pp. 4982-4993 ◽  
Author(s):  
Hang Shi ◽  
Irene Xagoraraki ◽  
Kristin N. Parent ◽  
Merlin L. Bruening ◽  
Volodymyr V. Tarabara
Keyword(s):  
Surface Water ◽  
Hydrophobic Interactions ◽  
Tap Water ◽  
Calf Serum ◽  
Cross Flow ◽  
Human Adenovirus ◽  
Deionized Water ◽  
Feed Water ◽  
Eluent Composition ◽  
Cross Flow Filtration

ABSTRACTThis paper examines the recovery of the enteric adenovirus human adenovirus 40 (HAdV 40) by cross-flow ultrafiltration and interprets recovery values in terms of physicochemical interactions of virions during sample concentration. Prior to ultrafiltration, membranes were either blocked by exposure to calf serum (CS) or coated with a polyelectrolyte multilayer (PEM). HAdV 40 is a hydrophobic virus with a point of zero charge between pH 4.0 and pH 4.3. In accordance with predictions from the extended Derjaguin-Landau-Verwey-Overbeek theory, the preelution recovery of HAdV (rpre) from deionized water was higher with PEM-coated membranes (rprePEM= 74.8% ± 9.7%) than with CS-blocked membranes (rpreCS= 54.1% ± 6.2%). With either membrane type, the total virion recovery after elution (rpost) was high for both deionized water (rpostPEM= 99.5% ± 6.6% andrpostCS= 98.8% ± 7.7%) and tap water (rpostPEM= 89% ± 15% andrpostCS= 93.7% ± 6.9%). The nearly 100% recoveries suggest that the polyanion (sodium polyphosphate) and surfactant (Tween 80) in the eluent disrupt electrostatic and hydrophobic interactions between the virion and the membrane. Addition of EDTA to the eluent greatly improved the elution efficacy (rpostCS= 88.6% ± 4.3% andrpostPEM= 87.0% ± 6.9%) with surface water, even when the organic carbon concentration in the water was high (9.4 ± 0.1 mg/liter). EDTA likely disrupts cation bridging between virions and particles in the feed water matrix or the fouling layer on the membrane surface. For complex water matrices, the eluent composition is the most important factor for achieving high virion recovery.IMPORTANCEHerein we present the results of a comprehensive physicochemical characterization of HAdV 40, an important human pathogen. The data on HAdV 40 surface properties enabled rigorous modeling to gain an understanding of the energetics of virion-virion and virion-filter interactions. Cross-flow filtration for concentration and recovery of HAdV 40 was evaluated, with postelution recoveries from ultrapure water (99%), tap water (∼91%), and high-carbon-content surface water (∼84%) being demonstrated. These results are significant because of the very low adenovirus recoveries that have been reported, to date, for other methods. The recovery data were interpreted in terms of specific interactions, and the eluent composition was designed accordingly to maximize HAdV 40 recovery.

Surface modification of reverse osmosis membranes with zwitterionic polymer to reduce biofouling

2015 ◽  
Vol 15 (5) ◽  
pp. 999-1010 ◽  
Author(s):  
Ahmed E. Abdelhamid ◽  
Mahmoud M. Elawady ◽  
Mahmoud Ahmed Abd El-Ghaffar ◽  
Abdelgawad M. Rabie ◽  
Poul Larsen ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Tap Water ◽  
Membrane Surface ◽  
Salt Content ◽  
Cross Flow ◽  
Membrane Properties ◽  
Cleaning Efficiency ◽  
Bacteria Growth ◽  
Cross Flow Filtration

The zwitterionic homopolymer poly[2-(methacryloyloxy)ethyl-dimethyl-(3-sulfopropyl) ammonium hydroxide was coated onto the surface of commercial polyamide reverse osmosis (RO) membranes. Aqueous solutions of the polymer at different concentrations were applied to modify the polyamide membranes through an in situ surface coating procedure. After membrane modification, cross-flow filtration testing was used to test the antifouling potential of the modified membranes. The obtained data were compared with experimental data for unmodified membranes. Each test was done by cross-flow filtering tap water for 60 hours. Yeast extract was added as a nutrient source for the naturally occurring bacteria in tap water, to accelerate bacteria growth. Fourier transform infrared spectroscopy, contact angle, scanning electron microscopy, atomic force microscopy, and permeation tests were employed to characterize membrane properties. The results confirmed that modifying the membranes enhanced their antifouling properties and cleaning efficiency, the fouling resistance to bacteria improving due to the increased hydrophilicity of the membrane surface after coating. In addition, the water permeability and salt rejection improved. This in situ surface treatment approach for RO membranes could be very important for modifying membranes in their original module assemblies as it increases water production and reduces the salt content.

scholarly journals Functional Modification of Cellulose Acetate Microfiltration Membranes by Supercritical Solvent Impregnation

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 411
Author(s):  
Irena Zizovic ◽  
Marcin Tyrka ◽  
Konrad Matyja ◽  
Ivana Moric ◽  
Lidija Senerovic ◽  
...  
Keyword(s):  
Cellulose Acetate ◽  
Ion Beam ◽  
Antibacterial Properties ◽  
Cross Flow ◽  
Batch Mode ◽  
Impregnation Process ◽  
Supercritical Solvent ◽  
Cross Flow Filtration ◽  
Microfiltration Membranes ◽  
The Impact

This study investigates the modification of commercial cellulose acetate microfiltration membranes by supercritical solvent impregnation with thymol to provide them with antibacterial properties. The impregnation process was conducted in a batch mode, and the effect of pressure and processing time on thymol loading was followed. The impact of the modification on the membrane’s microstructure was analyzed using scanning electron and ion-beam microscopy, and membranes’ functionality was tested in a cross-flow filtration system. The antibiofilm properties of the obtained materials were studied against Staphyloccocus aureus and Pseudomonas aeruginosa, while membranes’ blocking in contact with bacteria was examined for S. aureus and Escherichia coli. The results revealed a fast impregnation process with high thymol loadings achievable after just 0.5 h at 15 MPa and 20 MPa. The presence of 20% of thymol provided strong antibiofilm properties against the tested strains without affecting the membrane’s functionality. The study showed that these strong antibacterial properties could be implemented to the commercial membranes’ defined polymeric structure in a short and environmentally friendly process.

Effects of Water Source, Dilution, Storage, and Bacterial and Fecal Loads on the Efficacy of Electrolyzed Oxidizing Water for the Control of Escherichia coli O157:H7

2004 ◽  
Vol 67 (7) ◽  
pp. 1377-1383 ◽  
Author(s):  
S. M. L. STEVENSON ◽  
S. R. COOK ◽  
S. J. BACH ◽  
T. A. McALLISTER
Keyword(s):  
Escherichia Coli ◽  
Bactericidal Activity ◽  
Storage Temperature ◽  
Uv Light ◽  
Tap Water ◽  
Organic Matter Content ◽  
Water Source ◽  
Deionized Water ◽  
Escherichia Coli O157 ◽  
E Coli

To evaluate the potential of using electrolyzed oxidizing (EO) water for controlling Escherichia coli O157:H7 in water for livestock, the effects of water source, electrolyte concentration, dilution, storage conditions, and bacterial or fecal load on the oxidative reduction potential (ORP) and bactericidal activity of EO water were investigated. Anode and combined (7:3 anode:cathode, vol/vol) EO waters reduced the pH and increased the ORP of deionized water, whereas cathode EO water increased pH and lowered ORP. Minimum concentrations (vol/vol) of anode and combined EO waters required to kill 104 CFU/ml planktonic suspensions of E. coli O157:H7 strain H4420 were 0.5 and 2.0%, respectively. Cathode EO water did not inhibit H4420 at concentrations up to 16% (vol/vol). Higher concentrations of anode or combined EO water were required to elevate the ORP of irrigation or chlorinated tap water compared with that of deionized water. Addition of feces to EO water products (0.5% anode or 2.0% combined, vol/vol) significantly reduced (P < 0.001) their ORP values to <700 mV in all water types. A relationship between ORP and bactericidal activity of EO water was observed. The dilute EO waters retained the capacity to eliminate a 104 CFU/ml inoculation of E. coli O157:H7 H4420 for at least 70 h regardless of exposure to UV light or storage temperature (4 versus 24°C). At 95 h and beyond, UV exposure reduced ORP, significantly more so (P < 0.05) in open than in closed containers. Bactericidal activity of EO products (anode or combined) was lost in samples in which ORP value had fallen to ≤848 mV. When stored in the dark, the diluted EO waters retained an ORP of >848 mV and bactericidal efficacy for at least 125 h; with refrigeration (4°C), these conditions were retained for at least 180 h. Results suggest that EO water may be an effective means by which to control E. coli O157:H7 in livestock water with low organic matter content.

Cross-Flow Ultrafiltration Used in Algal High Rate Oxidation Pond Treatment of Saline Organic Effluents with the Recovery of Products of Value

1992 ◽  
Vol 25 (10) ◽  
pp. 319-327 ◽  
Author(s):  
P. D. Rose ◽  
B. A. Maart ◽  
T. D. Phillips ◽  
S. L. Tucker ◽  
A. K. Cowan ◽  
...  
Keyword(s):  
Waste Treatment ◽  
Production Systems ◽  
Algal Cell ◽  
Cross Flow ◽  
Viable Cell ◽  
High Rate ◽  
Limiting Factor ◽  
Algal Biotechnology ◽  
Cross Flow Filtration ◽  
Flow Filtration

An algal high rate oxidation ponding process for treating organic s present in saline effluents has been described. The extreme halophile Dunaliella salina can be made to predominate in the system by manipulating salinity, producing products of value together with a waste treatment function. Application in treating tannery saline organic wastes was examined. Techniques appropriate for the harvesting of micro-algae from this and other algal production systems presents a limiting factor in the development of algal biotechnology. Cross-flow filtration was evaluated as a technique for micro-algal cell separation. Both microfiltration and ultrafiltration were found to produce effective algal removal from the medium, Cross-flow ultrafiltration with a polyethersulfone coated tubular filter produced effective separation with the production of cell concentrates in a viable condition. Flux rates of 30 - 40 LMH fall within acceptable levels for application in industrial processes. Cell shattering observed with microfiltration precludes its use for recovering whole or viable cell concentrates.

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