Energy cost for desalination evaporation versus reverse osmosis

2011 ◽  
Vol 4 (3) ◽  
pp. 277 ◽  
Author(s):  
M. Rognoni ◽  
M.P. Ramaswamy ◽  
J. Justin Robert Paden
Keyword(s):  
2021 ◽  
Vol 18 (4) ◽  
pp. 53-62
Author(s):  
Ashok Tambi ◽  
A.B. Gupta ◽  
Sushant Upadhyaya

This study presents a performance analysis in terms of energy and other costs related to the unit cost of water produced in 16 identical community scale reverse osmosis units installed at Jaipur. The energy consumptions indicated that these plants suffer from accelerated fouling of membranes due to scaling by hardness causing substances, which results in a significant loss of useful life of the membranes. The study shows that the overall cost of water production has four major components. Energy cost varies between Rs. 0.025 and 0.079 per litre. Salary cost varies between Rs. 0.04 to 0.20 per litre. Spares and chemical cost varies between Rs. 0.01 to 0.04 per litre. In addition, repayment of capital invested has also been considered with and without solar integration to arrive at realistic cost estimates over a perceived life cycle of the system. The breakeven achieved by selling 4600–5200 litre water @ Rs. 0.2 per litre per day if repayment of capital investment is not considered, as these units were installed under CSR, while it varies between 8800 and 9600 litre if repayment of capital investment is also considered as an independent business venture. This analysis substantiates that potential exists for the long-term sustainability of these systems.


Author(s):  
H. K. Plummer ◽  
E. Eichen ◽  
C. D. Melvin

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.


1970 ◽  
Vol 126 (3) ◽  
pp. 526a-526 ◽  
Author(s):  
A. N. Goldbarg
Keyword(s):  

IEE Review ◽  
1993 ◽  
Vol 39 (2) ◽  
pp. 66
Author(s):  
R. Alan Davis

2014 ◽  
Vol 4 (2) ◽  
pp. 467-476
Author(s):  
Nisha Sharma ◽  
Jaspal Singh ◽  
Barjinder Kaur

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.


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