Copepods in supernatant return

Hello friends,

I have an issue with copeopds (water fleas) increasing the turbidity in the supernatant return water at a water treatment works. The supernantant is returned to the head of the works . Any suggestions on how to get rid of the critters  before they develop into adults?

Thanks,

Roger

Taxonomy

• Drinking Water Treatment
• Water Treatment & Control
• water treatment
• water treatment

4 Answers

1. Have you looked at UV or ozone to kill the copepods?

   1 Comment

   1. we have ozone at the inlet . It dosent seem to be effective. 

2. These are a real resource for any aquatic food chain, put them in the river. Dry them and sell them to the aquarium industry and fish breeders. Live aquatic food is hard to acquire.

3. Hello Roger, I had experiences with water fleas in activated sludge systems during hot weather.  The solution was to lower the MCRT (mean cell residence time) gradually until it was shorter than the life cycle of the water fleas.   The fleas can survive anoxic conditions for a long time.  The fleas did not survive a 24 hour anaerobic process.  You could also kill fleas with shock chlorination of the supernatant.    Interesting problem.  Let us know how it works out.  Best wishes,  Tom

4. Hi Roger,

   If you are looking for filtration of the fleas please send me an E-mail and I will help you out. mikael.bengtsson@nordicwater.com 

   1 Comment

   1. mikael the email address you provided said it was invalid. Around 10ML of supernatant is returned to the head of the water treatment works. the water fleas (which have been killed by chlorine) are addding 10-20% to the raw was turbidity which is increasing treatment costs. If you have a filtration solution i would be interested to hear back from you. thanks