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Flashcards in Reverse Osmosis Deck (135)
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1

The Village Marine Tec. (VMT) PW400 Seawater Desalinator is a ____

Single-pass fully transportable purification system that uses reverse osmosis (RO) as its method of seawater desalination

2

The Village Marine Tec. (VMT) PW400 Seawater Desalinator produces potable drinking quality water with salt concentrations of _____ from seawater with salt concentrations as high as _____

< 500 ppm
35000 ppm

3

Naturally occurring phenomenon in which a semi-permeable membrane separates a pure and a concentrated solution

Osmosis

4

Preferentially passes a particular substance

Semi-permeable membrane

5

This potential, referred to as osmotic pressure, increases in proportion relative to ____

Concentration of a solution

6

Every fluid has an ____ that is directly related to the type and amount of solids in solution

Inherent potential

7

A concentrated solution has an osmotic pressure that is ____ than that of a pure solution

Higher

8

In an osmotic system, the less concentrated solution will attempt to equalize the concentrations of both solutions by ____

Migrating across the semi-permeable membrane

9

Salt water is pressurized on one side of the semi-permeable membrane. The pressure must be high enough to exceed the ___ to cause reverse osmotic flow of water

Osmotic pressure

10

Product water

Pure water

11

Feed water

Concentrated solution

12

If the applied pressure is increased in an attempt to gain more product water, a point is reached at which the membrane becomes ____

Fouled by precipitated salts and other undissolved material from the water

13

This RO unit will produce permeate (product water) with a quality of ____ in accordance with World Health Organization (WHO) standards for drinking water

< 500 ppm TDS

14

Permeate

Drinking water

15

With constant salinity and pressure and increasing temperature, permeate TDS ____, Capacity ____

Increases
Increases

16

With constant temperature and pressure and increasing salinity, permeate TDS ____, Capacity ____

Increases
Decreases

17

With constant temperature and salinity and increasing pressure, permeate TDS _____, Capacity ____

Decreases
Increases

18

If feedwater salt concentration decreases, the product water flow rate should not be allowed to increase more than ___ above rated flow

20%

19

Feed pressure may need to be ___ to maintain rated flow in brackish water or fresh water applications

Lowered

20

Experience has shown that operating in waters such as the Chesapeake Bay, system pressure can be reduced from the normal ___ to ___

750-800 psi
350-550 psi

21

As the salinity of the water is lower, pressure can be ___

Decreased

22

Typical sea water contains about __ salinity whereas in a bay, it is about ___

33%
20%

23

The RO system can be adjusted to maintain a constant permeate output when feedwater temperature and salinity is other than nominal. This can be down by controlling system pressure manually via ___

The back pressure regulation valve located in the system brine piping

24

As permeate flow decreases, the operator can ____ to increase system pressure

Throttle the pressure regulation valve closed

25

Throttling the pressure regulation valve closed will ___

Increase the permeate output and mitigate the effect of a decrease in temperature or an increase in salinity

26

Operating the unit at more than 20% of rated capacity in low salinity water can ___

Damage the membranes

27

R/W temperature range (87)

33 - 113*F (1 - 43*C)

28

Minimum R/W inlet pressure (87)

Static suction pressure

29

Maximum R/W inlet pressure (87)

20 psi

30

Design RO element pressure (87)

800 psi