×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Water Treatment Plant Flow Loss

Water Treatment Plant Flow Loss

Water Treatment Plant Flow Loss

(OP)
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?

RE: Water Treatment Plant Flow Loss

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.

RE: Water Treatment Plant Flow Loss

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

RE: Water Treatment Plant Flow Loss

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.

RE: Water Treatment Plant Flow Loss

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.

RE: Water Treatment Plant Flow Loss

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.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources