Water and Wastewater.com Help Forums - Filiment Problem...O21N....

YaBB Newbies

Offline

I love Water and
Wastewater.com

Posts: 6

Company or Organization: Lebanon NH WWTP

Filiment Problem...O21N....
Jun 26^th, 2012, 10:16am

We have had to Chlorinate our RAS more times than ever before. I dont know what has changed with our process to breed this filiment. I know its a volitile acids filiment, so I have looked into septage, centrate concentration, sewer seperation, and primary removal. Can't seem to pinpoint the problem. Anyone else have problems with this before and what was the cause. We are a convertional activated sludge plant, primary and secondary clarifiers. Septage is contained and bled slowly. Any help would be great!

Back to top

IP Logged

grrun God Member Offline WaterandWastewa ter.Com is the best! Posts: 3525 Pekin, IL Gender: Company or Organization: Freelance Environmental Engine	Re: Filiment Problem...O21N.... Reply #1 - Jun 26^th, 2012, 2:07pm Your problem may be due to operational practices rather than feed composition. What is the sludge age, effluent TSSs, influent & effluent BOD, etc. for your treatment? grrun
Back to top	IP Logged

The sludge judge

God Member

Offline

Posts: 649
Wisconsin
Gender: male

Company or Organization: private

Re: Filiment Problem...O21N....
Reply #2 - Jun 26^th, 2012, 2:23pm

I've had success with volatile acids filaments by utilizing step feed (this dilutes the volatile acid concentration because they are taken up within 30 min or so) and diluting the influent- we have a plant where we recycle a percentage of the effluent back into their EQ tank to dilute the volatile acids, this works very well.

Raising the redox in the collection system (calcium nitrate) will work. Also helpful is pre-chlorination of the influent/ hydrogen peroxide addition to the collection system. This won't oxidize all of the VFA's but will help freshen up the water and oxidize sulfide, which 021N grows on too. (does the 021N have sulfur granules?)

Perhaps the warmer weather is increasing the biological activity in your collection system or maybe a longer retention time now?

You really need to do a VFA profile of the plant to determine where they're coming from. Check the collection system, primary, sludge handling supernate etc.

Feel free to send me a pm if you'd like.

hope this helps,

Ryan

Back to top

IP Logged

Handsome Dan

YaBB Newbies

Offline

I love Water and
Wastewater.com

Posts: 6

Company or Organization: Lebanon NH WWTP

Re: Filiment Problem...O21N....
Reply #3 - Jun 27^th, 2012, 11:59am

Hi,
Thanks for the comments. Grrun, Here is the info you wanted. Our sludge age or mcrt is currently nine days. Our effluent t.s.s. is around 5mg/l and our influent/eff BOD is 250/5 mg/l. We have operated the plant like this forever, and just started having a problem around 2010. We get the filiment, hit it for a few days at 2lbs per thousand and it goes away. Only to come back in a month or so.

Sludge judge, I like your thoughts on the collection system. We have done some major stormwater seperations in the past two years. We haven't stained to see granules, so will have to do so. We are expecting a big upgrade soon and will switch to BNR treatment. This should help alot. Thanks for the imput....keep it coming!!

Back to top

IP Logged

The sludge judge

God Member

Offline

Posts: 649
Wisconsin
Gender: male

Company or Organization: private

Re: Filiment Problem...O21N....
Reply #4 - Jun 27^th, 2012, 1:06pm

The upgrade to BNR will probably help. You already have the organic acids for bio P removal, now you can hopefully use them to your advantage.

If you do the sample in situ or even within a day or two you should still see the sulfur granules if they're present with 021N under phase contrast. The S test will be positive if they're growing on sulfide, but the sulfur granules dissapear during transit. I sent you my mailing address if you'd like me to take a look.

As for sludge age: 021N grows between sludge ages of 3 days to 40+ so changes here won't help with this problem.

021N is a rough one, bridges the flocs and the SVI can go through the roof overnight. You have my sympathy. Chlorine works well because there's no sheath.

best regards,

Ryan

Back to top

IP Logged

almar1965

God Member

Offline

Composting is the
work of Satan !!

Posts: 1269
Santiago
Gender: male

Company or Organization: Sinquiver Ltda

Re: Filiment Problem...O21N....
Reply #5 - Jun 29^th, 2012, 4:38pm

Hi

O21N is closely related to Thiothrix (Eikelboom et al.) and responds to increased in available sulphur. It seems to refer sulphide and keeping the DO at a good level seems to reduce levels of this filament fairly well. The volatile acids tend to form under septic conditions, and this will mean lower dissolved oxygen at points. This will contribute to the sulphate reducing to sulphide....giving the O21N tow food sources.

Increase DO and eliminate septic dead spots and you should have a much easier time.

regards
Alistair

Back to top

IP Logged

Handsome Dan YaBB Newbies Offline I love Water and Wastewater.com Posts: 6 Company or Organization: Lebanon NH WWTP	Re: Filiment Problem...O21N.... Reply #6 - Jul 6^th, 2012, 10:53am Hello, We run our D.O. at a 2.0 mg/l and have taken actually less septage this year than previously. The D.O. coming into aeration runs typically around a 0.6 mg/l
Back to top	IP Logged

The sludge judge God Member Offline Posts: 649 Wisconsin Gender: Company or Organization: private	Re: Filiment Problem...O21N.... Reply #7 - Jul 6^th, 2012, 12:19pm controlling 021N isn't as easy as having enough DO. To control it you need to either oxidize or dilute (step feed) the VFAs and sulfide. I've seen bulking with this filament in DO greater than 4 mg/L. In industry lack of nitrogen can be a cause, but that's not a factor here (municipal). hope this is of some help, Ryan
Back to top	IP Logged