Physical processes Qs Flashcards
Explain the membrane process for dissolved solids
Uses reverse osmosis and nanofiltration to remove dissolved solids. For NF, all the solids and macromolecules are completely retained and don’t go through the membrane.
What is reverse osmosis?
Aiming to concentrate a salt solution even more to achieve clean water, so a pressure that’s higher than the osmotic pressure is applied on the salty water side to push the clean water through the membrane. This works against the gradient and increases it between the two sides. Most common membrane used are spiral wound modules.
Name and explain different membrane applications
- Used in the milk industry, condensate recovery using reverse osmosis condensate from whey powder production.
- Use of membranes to recover spent cleaning productions. E.g. clean in place system (CIP). Pipeline circuits and plant items are cleaned without dismantling or opening of equipment.
Describe the Ion exchange process
: Exchange of the functional group of resin with the ions to be removed from the solution. Ion exchange is strongly dependent on pH levels because the solubility of metals depends on pH, low pH most metals are highly soluble and not taking part in IOX. Its main applications are to remove heavy metals
What is a fixed bed adsorber?
For the binding of certain components from gas or liquid mixtures on the surface of porous surface-active agents. Its main design parameters are adsorbent loading q, contact time and breakthrough point. Main application is for the removal of dissolved organics and heavy metal removal.
How does the MTZ change if the inflow velocity of the fixed bed adsorber increases?
The MTZ zone rises up the adsorber bed to the top, removing the saturated area
Define the breakthrough of an activated carbon filter
The breakthrough is reached as soon as the concentration in the outflow of the filter exceeds a set value. It occurs when most adsorption sites are occupied.
