Evaluation of the low pressure RO and NF membranes for an alternative tyreatment of Buyukcekmece Lake

The recent development of new generation LPRO and LPNF membranes has received attention for application in the field of wastewater and water treatment through an increasingly stringent regulation for drinking water purposes and water reclamation. This paper presents the pilot scale membrane separation studies on Buyukcekmece Lake in Istanbul with low pressure reverse osmosis (LPRO) and low pressure nanofiltration (LPNF) membranes. The application to treatment of anionic and cationic pollutants (Na+, Mg2+, Ca2+, Cl–, SO42–, NO3–) has been investigated as a function of transmembrane pressure and recovery rate under very low pressure range (3, 4, 5, and 6 bars). Flux value increased with increasing pressure and the membrane type of TFC-S gave the highest fluxes. The rejections of ions were increased with transmembrane pressure for two types of membranes. TFC-HR membrane rejection performance was better than the TFC-S membrane for all anionic and cationic pollutants. As recovery rate rises, the rejections were decreased.

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Effect of operating conditions on rejection of anionic pollutants in the water environment by nanofiltration especially in very low pressure range

Water Science & Technology ◽

10.2166/wst.1996.0199 ◽

1996 ◽

Vol 34 (9) ◽

pp. 149-156 ◽

Cited By ~ 3

Author(s):

C. Ratanatamskul ◽

K. Yamamoto ◽

T. Urase ◽

S. Ohgaki

Keyword(s):

Water Environment ◽

Chloride Ions ◽

Operating Conditions ◽

Transmembrane Pressure ◽

Operating Pressure ◽

Nanofiltration Membranes ◽

Single Solution ◽

Crossflow Velocity ◽

Membrane Type ◽

New Generation

The recent development of new generation LPRO or nanofiltration membranes have received attraction for application in the field of wastewater and water treatment through an increasingly stringent regulation for drinking purpose and water reclamation. In this research, the application on treatment of anionic pollutants (nitrate, nitrite, phosphate, sulfate and chloride ions) have been investigated as functions of transmembrane pressure, crossflow velocity and temperature under very much lower pressure operation range (0.49 to 0.03 MPa) than any other previous research used to do. Negative rejection was also observed under very much low range of operating pressure in the case of membrane type NTR-7250. Moreover, the extended Nernst-Planck model was used for analysis of the experimental data of the rejection of nitrate, nitrite and chloride ions in single solution by considering effective charged density of the membranes.

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Immersed membranes activated sludge process applied to the treatment of municipal wastewater

Water Science & Technology ◽

10.2166/wst.1998.0688 ◽

1998 ◽

Vol 38 (4-5) ◽

pp. 437-442 ◽

Cited By ~ 23

Author(s):

Pierre Côté ◽

Hervé Buisson ◽

Matthieu Praderie

Keyword(s):

Activated Sludge ◽

Membrane Filtration ◽

Municipal Wastewater ◽

Pilot Scale ◽

Activated Sludge Process ◽

Hybrid Techniques ◽

Membrane Flux ◽

Aeration Conditions ◽

New Generation ◽

Better Than

An immersed membrane activated sludge process has been evaluated at pilot scale by Anjou Recherche. This process represents a new generation of hybrid techniques, which aims at coupling biological treatment and membrane filtration functions, in a configuration adapted to the treatment of municipal wastewater. The process was evaluated under extended aeration conditions, but with concentrations of biomass of between 15 to 25 gMLSS/l, which corresponded to volumetric loadings of between 1.2 to 2.3 kg COD/m3/d. Under these conditions, COD and TKN removal were better than 96% and 95%, respectively. The membrane ensured total removal of suspended solids and produced treated water of excellent bacteriological quality. The sludge production stabilized at 0.20 gDS/kg COD removed. The membrane flux was stable for all conditions tested.

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Comparison of UV and chlorine pretreatment in pilot plant micro-filter membrane separation for drinking water

Water Science & Technology Water Supply ◽

10.2166/ws.2001.0120 ◽

2001 ◽

Vol 1 (5-6) ◽

pp. 245-251

Author(s):

J.Y. Huang ◽

S. Takizawa ◽

K. Fujita

Keyword(s):

Uv Irradiation ◽

Water Purification ◽

Membrane Fouling ◽

Membrane Filtration ◽

Membrane Separation ◽

Pilot Scale ◽

Transmembrane Pressure ◽

Formation Potential ◽

Dead End ◽

Solids Removal

Methods to control bio-fouling, i.e. UV-irradiation and chlorination pretreatment were evaluated in dead-end membrane filtration. Pilot-scale experiments were carried out at Kosuzume Water Purification Plant, which is located at the Sagami River in Kanagawa Prefecture, Japan. As a result, both UV-irradiation and chlorination strongly suppressed the increase of transmembrane pressure and prevented bio-fouling. However, in the case of pre-chlorination, the membrane color changed from white to brown after a long use, causing irreversible membrane fouling due probably to manganese adsorption. Suspended solids removal by membrane filtration decreased the formation potential for CHCl3, but didn't affect the CHCl2Br and CHClBr2 formation potentials. Pre-chlorination, however, increased both CHCl2Br and CHClBr2 formation potentials, thus making up for the reduction in CHCl3 formation potential due to membrane filtration. UV-irradiation pretreatment combined with membrane filtration in the water purification process is regarded as an accessible method and was proved effective in controlling bio-fouling, which gave us a better water quality without increasing trihalomethanes in contrast to pre-chlorination.

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Finding the Right Problems: Some HREM Applications to Interfaces

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100111938 ◽

1984 ◽

Vol 42 ◽

pp. 376-379

Author(s):

D. Cherns

Keyword(s):

Grain Boundaries ◽

High Resolution Electron Microscopy ◽

Boundary Structure ◽

Atomic Structures ◽

Grain Boundary Structure ◽

Resolution Electron ◽

Point To Point ◽

The Right ◽

New Generation ◽

Better Than

The use of high resolution electron microscopy (HREM) to determine the atomic structure of grain boundaries and interfaces is a topic of great current interest. Grain boundary structure has been considered for many years as central to an understanding of the mechanical and transport properties of materials. Some more recent attention has focussed on the atomic structures of metalsemiconductor interfaces which are believed to control electrical properties of contacts. The atomic structures of interfaces in semiconductor or metal multilayers is an area of growing interest for understanding the unusual electrical or mechanical properties which these new materials possess. However, although the point-to-point resolutions of currently available HREMs, ∼2-3Å, appear sufficient to solve many of these problems, few atomic models of grain boundaries and interfaces have been derived. Moreover, with a new generation of 300-400kV instruments promising resolutions in the 1.6-2.0 Å range, and resolutions better than 1.5Å expected from specialist instruments, it is an appropriate time to consider the usefulness of HREM for interface studies.

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Use of Low Pressure Mercury Lamps for the Photodecomposition of Iron Cyanide in Gold Mill Effluents

Water Quality Research Journal ◽

10.2166/wqrj.1985.022 ◽

1985 ◽

Vol 20 (2) ◽

pp. 111-119 ◽

Cited By ~ 1

Author(s):

J.H. Carey ◽

S.A. Zaidi

Keyword(s):

Ultraviolet Light ◽

High Intensity ◽

Experimental Evaluation ◽

Low Pressure ◽

Pilot Scale ◽

Weak Acid ◽

Potassium Ferricyanide ◽

Technical Feasibility ◽

Iron Cyanide ◽

Scale Test

Abstract The use of ultraviolet light (UV) from low pressure mercury lamps for destroying iron cyanide in synthetic and actual gold mill effluents was evaluated in this study. For the light intensities used in this study, UV irradiation was not able to efficiently destroy cyanide. However, it converted iron cyanide to a weak acid dissociable form which was destroyed by chlorine. Data from several bench-scale tests and one pilot scale test were used to estimate quantum efficiencies (moles iron cyanide destroyed/einstein). These efficiencies ranged from 0.2% to 1%; approximately 30% to 90% lower than those reported in the literature for potassium ferricyanide. The data collected during the study demonstrated the technical feasibility of using UV in conjunction with chlorination for destroying iron cyanide in gold mill effluents. However, low pressure mercury lamps do not appear to be a practical UV source for this purpose. Irradiation with high intensity lamps may be more practical and is recommended for experimental evaluation.

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Masers as probes of the gas dynamics close to forming high-mass stars

Proceedings of the International Astronomical Union ◽

10.1017/s1743921317009796 ◽

2017 ◽

Vol 13 (S336) ◽

pp. 201-206 ◽

Cited By ~ 1

Author(s):

Luca Moscadelli ◽

Alberto Sanna ◽

Ciriaco Goddi

Keyword(s):

Gas Dynamics ◽

Very Long Baseline Interferometry ◽

High Mass ◽

Powerful Technique ◽

Long Baseline ◽

Vlbi Observations ◽

Massive Forming ◽

Typical Distances ◽

New Generation ◽

Better Than

AbstractImaging the inner few 1000 AU around massive forming stars, at typical distances of several kpc, requires angular resolutions of better than 0″.1. Very Long Baseline Interferometry (VLBI) observations of interstellar molecular masers probe scales as small as a few AU, whereas (new-generation) centimeter and millimeter interferometers allow us to map scales of the order of a few 100 AU. Combining these informations all together, it presently provides the most powerful technique to trace the complex gas motions in the proto-stellar environment. In this work, we review a few compelling examples of this technique and summarize our findings.

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Dynamic Viscosity of Compressed Water to 10 Kilobar and Steam to 1500°C

Journal of Mechanical Engineering Science ◽

10.1243/jmes_jour_1969_011_024_02 ◽

1969 ◽

Vol 11 (2) ◽

pp. 189-205 ◽

Cited By ~ 14

Author(s):

E. A. Bruges ◽

M. R. Gibson

Keyword(s):

Gaseous Phase ◽

Dynamic Viscosity ◽

Low Temperatures ◽

Pressure Range ◽

Low Pressure ◽

Temperature Range ◽

Inversion Temperature ◽

Pressure Steam ◽

Correlating Equations ◽

First Time

Equations specifying the dynamic viscosity of compressed water and steam are presented. In the temperature range 0-100cC the location of the inversion locus (mu) is defined for the first time with some precision. The low pressure steam results are re-correlated and a higher inversion temperature is indicated than that previously accepted. From 100 to 600°C values of viscosity are derived up to 3·5 kilobar and between 600 and 1500°C up to 1 kilobar. All the original observations in the gaseous phase have been corrected to a consistent set of densities and deviation plots for all the new correlations are given. Although the equations give values within the tolerances of the International Skeleton Table it is clear that the range and tolerances of the latter could with some advantage be revised to give twice the existing temperature range and over 10 times the existing pressure range at low temperatures. A list of the observations used and their deviations from the correlating equations is available as a separate publication.

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Unprecedented CO2 adsorption behaviour by 5A-type zeolite discovered in lower pressure region and at 300 K

Journal of Materials Chemistry A ◽

10.1039/d0ta09944a ◽

2021 ◽

Author(s):

Akira Oda ◽

Suguru Hiraki ◽

Eiji Harada ◽

Ikuka Kobayashi ◽

Takahiro Ohkubo ◽

...

Keyword(s):

Pressure Range ◽

Co2 Adsorption ◽

Low Pressure ◽

Lower Pressure ◽

Dft Studies ◽

Adsorption Behaviour ◽

Zeolite Sample ◽

Pressure Region ◽

Type Zeolite ◽

Efficient Adsorbent

The NaCaA-85 zeolite sample which works as an efficient adsorbent for CO2 at RT and in low pressure range was found and its specificity is nicely explained by the model composed of CO2 pinned by two types of Ca2+ ions through far-IR and DFT studies.

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An ICR Study of an Association Reaction at Low Pressure

Symposium - International Astronomical Union ◽

10.1017/s0074180900072764 ◽

1980 ◽

Vol 87 ◽

pp. 305-306

Author(s):

M.J. Mcewan ◽

V. G. Anicich ◽

W.T. Huntress ◽

P. R. Kemperer ◽

M. T. Bowers

Keyword(s):

Pressure Range ◽

Rate Coefficient ◽

Low Pressure ◽

Second Order ◽

Radiative Association ◽

Association Reaction

An ICR investigation of the association reactionCH3+ + HCN CH3.HCN+has shown the reaction follows second order kinetics over the pressure range 1 × 10-6 to 3 × 10-4 Torr with a rate coefficient of 2 × 10-10 cm3s-1. These results can be interpreted in terms of a saturated 3-body or radiative association mechanism.

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