Re: DIG-L: Ammonia in Biomethanation !!!!!!

["OLEL" <olel@vsnl.net>]

Thanks for an instant responce !!

1.The pH of the Distillery Spentwash is around 4. But the pH of the Raw effluent is adjusted to 6 to 6.5 before it enters the UASB system by using the Biocarbonate Alkalinity from the treated Effluent(Which is recycled in a buffer Tank , where it gets mixed with the raw Effluent) and an external addition of Lime to the Buffer Tank.

2. We are not using Proprietory Bactria or Organic Media Cells.

3. I didn't understant what  you mean by UASB as a Dilute Process.Would be grateful if you could explain.

   The COD of the Distillery Spentwash is 100000 mg/L. The organic Concentration entering the reactor after dilution and mixing with the recycled flow is 30000- 40000 mg/L(COD) !!!!

 

Thanks again for the responce.,

Avadhut Bapat.

----- Original Message -----

From: cbocch

To: OLEL

Sent: Friday, December 07, 2001 10:53 AM

Subject: Re: DIG-L: Ammonia in Biomethanation !!!!!!

Chances are the pH is the determination factor of the excess ammonia.
Are you using proprietory bacteria?
Organic media cells for the bacteria?

UASB is a very dilute process and the absence of H2S is not surprising; but this is dependant on the throughflow rate of your wastes.

A low pH will deliver excess ammonia residues.

Just my two bobs worth

good luck

Regards
Carmine Bocchino

OLEL wrote:

I operate an anaerobic UASB system for the treatment of 700m3/day Cane molasses based Distillery Spentwash.This plant has been in operation for the last 6 years.One of the UASB ractors was recently opened for the repairs of the feed distribution Network. Besides many interesting findings , one puzzling observation was that, throughout the period when the Anaerobic Biomass was being removed from the reactor(i. e. for about 3  weeks) , a very strong odour of Ammonia was persistent in the reactor.  Actually H2S smell was expected as the Spentwash contains high concentrations of sulfates and the Anaerobic Biomass contains Sulfate Reducing Bacteria. But No H2S smell was encountered. Can somebody please throw some light on the possible reasons for the presence of this strong Ammonia smell ?? P.S. 1.No external Nitrogen was being added as the TKN  concentration in the distillery spentwash is in the range of 1000 to 1500 mg/L. 2. Moderate quantities of yeast may have accumulated in the reactor(Source: Distillery Spentwash). Thanks., Avadhut Bapat