A speculative hybrid reverse osmosis/electrodialysis unit operation

Desalination ◽  
2007 ◽  
Vol 214 (1-3) ◽  
pp. 11-30 ◽  
Author(s):  
John Pellegrino ◽  
Craig Gorman ◽  
Laura Richards
Keyword(s):  
Reverse Osmosis ◽  
Unit Operation

Waste-Treatment Applications of Reverse Osmosis

1975 ◽  
Vol 97 (1) ◽  
pp. 246-251 ◽  
Author(s):  
J. E. Cruver
Keyword(s):  
Reverse Osmosis ◽  
Large Scale ◽  
Waste Treatment ◽  
Operating Costs ◽  
Textile Dye ◽  
Secondary Effluent ◽  
Unit Operation ◽  
Waste Streams ◽  
Metal Finishing ◽  
The Status

Reverse osmosis has come of age as a unit operation and is finding increasing usage in water and waste treatment. Large-scale (100–1000 gpm) units are currently operating throughout the world on a wide variety of feed streams. This paper summarizes the status of development of reverse-osmosis processing of municipal and industrial waste streams. Plants are described which process secondary effluent, metal-finishing wastes, and textile dye wastes. Capital and operating costs are also presented for reverse osmosis and compared with those of other desalting methods.

Cellulose Acetate Reverse Osmosis Membrane Structure

1972 ◽  
Vol 30 ◽  
pp. 528-529
Author(s):  
H. K. Plummer ◽  
E. Eichen ◽  
C. D. Melvin
Keyword(s):  
Cellulose Acetate ◽  
Reverse Osmosis ◽  
Membrane Structure ◽  
Freeze Drying ◽  
Dense Layer ◽  
Water Removal ◽  
Reverse Osmosis Membrane ◽  
Correct Interpretation ◽  
Electron Image ◽  
Scanning Electron

Much of the work reported in the literature on cellulose acetate reverse osmosis membranes has raised new and important questions with regard to the dense or “active” layer of these membranes. Several thickness values and structures have been attributed to the dense layer. To ensure the correct interpretation of the cellulose acetate structure thirteen different preparative techniques have been used in this investigation. These thirteen methods included various combinations of water substitution, freeze drying, freeze sectioning, fracturing, embedding, and microtomy techniques with both transmission and scanning electron microscope observations.It was observed that several factors can cause a distortion of the structure during sample preparation. The most obvious problem of water removal can cause swelling, shrinking, and folds. Improper removal of embedding materials, when used, can cause a loss of electron image contrast and, or structure which could hinder interpretation.

Polycaprolactone based membranes for the degradation of diclofenac present in water samples using ZnO nanoparticles as the active agent

MRS Advances ◽  
2020 ◽  
Vol 5 (61) ◽  
pp. 3153-3161
Author(s):  
Marco Antonio Juárez Sánchez ◽  
Miguel Ángel Meléndez Lira ◽  
Celestino Odín Rodríguez Nava
Keyword(s):  
Zno Nanoparticles ◽  
Wastewater Treatment Plants ◽  
Active Agent ◽  
Heterogeneous Photocatalysis ◽  
Nano Particles ◽  
Electrical Characteristics ◽  
Unit Operation ◽  
Fields Of Study ◽  
Drug Contamination ◽  
Positive Results

AbstractDrug contamination in water is one of the current fields of study. Since 1990, the presence of drugs in drinking water has been a concern to scientists and public. In Mexico, these organic compounds are not efficiently removed in wastewater treatment plants; therefore, alternative methodologies have been studied that allow these compounds to have a high percentage of degradation or be completely degraded. One example of these techniques is heterogeneous photocatalysis which has obtained positive results in the degradation of drugs using ZnO nanoparticles. These are commonly selected for their electrical characteristics, even though they disperse in water and an additional unit operation is required to separate them from the liquid medium. To eliminate drugs with nano particles in a single stage, polycaprolactone-based membranes with adhered ZnO nanoparticles, by means of electrospinning, were prepared to degrade drugs such as diclofenac. The technique used has shown to efficiently break down diclofenac in 4 hours according to the capillary electrophoresis readings.

Performance Study of Some Reverse Osmosis Systems for Removal of Uranium and Total Dissolved Solids in Underground Waters of Punjab State, India

2014 ◽  
Vol 4 (2) ◽  
pp. 467-476
Author(s):  
Nisha Sharma ◽  
Jaspal Singh ◽  
Barjinder Kaur
Keyword(s):  
Drinking Water ◽  
Reverse Osmosis ◽  
State Government ◽  
Total Dissolved Solids ◽  
Internal Exposure ◽  
Drinking Water Source ◽  
Performance Study ◽  
Dissolved Solids ◽  
Underground Waters ◽  
High Concentrations

Radionuclides (uranium, thorium, radium, radon gas etc.) are found naturally in air, water, soil and rock. Everyday, we ingest and inhale these radionuclides through the air we breathe and through food and water we take. Out of the internal exposure via ingestion of radionuclides, water contributes the major portion. The natural radioactivity of water is due to the activity transfer from bed rock and soils. In our surveys carried out in the past few years, we have observed high concentrations of uranium and total dissolved solids (TDS) in drinking waters of some southern parts of Punjab State exceeding the safe limits recommended by national and international agencies. The main drinking water source is the underground water procured from different depths. Due to the highly saline taste, disorders in their digestive systems and other ailments, people are installing reverse osmosis (RO) systems in their houses. Some RO systems have been installed on commercial basis. The state government is also in the process of installing community RO systems at the village level. As high values of uranium are also undesired and may pose health hazards due to radioactivity and toxicity of uranium, we have conducted a survey in the field to study the performance of various RO systems for removal of uranium and TDS. Water samples from about forty RO systems from Faridkot, Mansa, Bathinda and Amritsar districts of Punjab State were collected and analyzed. Our results show that some RO systems are able to remove more than 99% of uranium in the underground waters used for drinking purposes. TDS values are also reduced considerably to the desired levels. So RO systems can be used to avoid the risk of unduly health problems posed by high concentrations of uranium and TDS in drinking water.

REDUCING ENVIRONMENTAL RISK OF LANDFILLS: LEACHATE TREATMENT BY REVERSE OSMOSIS

2012 ◽  
Vol 11 (12) ◽  
pp. 2319-2331 ◽  
Author(s):  
Maria Gavrilescu ◽  
Ana-Maria Schiopu ◽  
George Ciprian Piuleac ◽  
Corneliu Cojocaru ◽  
Ion Apostol ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Environmental Risk ◽  
Leachate Treatment
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