Water Treatment Plant Flow Loss 1

[OCall]

What average percent should be used to calculate the water loss for a water treatment plant. (What percent is used for filter backwashing and other uses.) I know that the rate will change depending on what treatment is used but where can I the assumed design rate to use?

 

[quark]

OCall!

For pressure quartz filter and activated charcoal filters the back wash is approximately 8 to 10% of (once) flow rate.
This is also ok for water softeners also. But if you have systems like RO its 20 to 30% on continuous basis, 20% being the best efficeint one.

Regards,

Truth: Even the hardest of the problems will have atleast one simple solution. Mine may not be one.

 

OCall!

For conventional drinking water treatment the rule of thumb is ~3% for filter backwashes. Anything higher than that would call for process optimization.

JJ

 

[quark]

J_J!

Generally filter backwash is done once in a day. If your water plant capacity is 30 cu.m/hr then the backwash is
3 cu.m per day, below which we found unclean water at userpoints. 3% you mentioned is what?

Regards,

Truth: Even the hardest of the problems will have atleast one simple solution. Mine may not be one.

 

The plant I work at produces approximately 120 - 140 mgd. Historically, the plant has lost approximately 7% due to blowdown of sediment from the clarification process (soon to be halted and dewatered), leaking valves (also to be reduced as result of new dewatering process coming on-line), and backwash. In looking back at the amount of water actually used for backwash purposes, it appears to be 3-4% of the raw influent flow.

 

[2765]

Loss of water in water treatment will depend upon the process.
Loss in clariflocculator:Calculate the suspended solid removed in kg/hr and convert the same for 2%sludge.
Loss in a DM plant is 7.5-10% of total output between two regeneration.Loss in softening plant is about 7.5%.
Loss in a sand fiter backwash is 5% of total output between two backwash.
Loss in an RO plant is reject rate of membrane which depends on the dissolved solids in raw water.