Struggles of Anaerobic Digestion

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I'm doing a bit of research about treatment chains as well as trying to understand a bit more about the effluents from AD and Biogas. 

Firstly, what industries are these systems mostly used in and, if any, what is used as a post-treatment for the water?

I'm aware that they can typically reduce COD to around 500ppm, depending on the application, but for people out there with experience what sort of chemicals/pollutants/colour does this process struggle to deal with?

What is being left in there that may stop you from reaching your discharge consent's or force you to look down further avenues for treatment?

Thanks for any help.

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5 Answers

  2. David:

    Our company manufactures, installs and commissions biodigesters.

    We convert everything that goes in to valuable products.

    The digestate has value. Water that is removed is used for "A" Grade irrigation water...or we are able to quite simply take the treatment one step further and produce potable drinking water.

    Some digestate is used as mulch and the remainder is used as fertilizer.

    In one case we press the digestate and produce a reasonably dry pellet that is then used to fuel a gasifier and to produce electricity. In one case the heat from the gasifier is used to heat a controlled atmosphere green house to grow vegetables all year around. In another case we use the heat in a kiln to dry timber for immediate use, much faster than air drying.

     

    We use Solutek to "super charge" the entire system. Solutek could be used as a standalone solution to clean and clarify effluent, this gives once again "A" Grade irrigation water.

     

    Please see attached paper.

     

    E. Hugh Pettman, Ph.D.

  3. I understand your question. But I do not understand the reason for using anaerobic digestion.  When using the proper microbes all waste is reduced into their elemental/nutritional state.  There is no leftover. Only potable drinking water. One earlier comment caught my eye. "Remaining ​organic matter ​are difficult ​to biodegrade ​by anaerobic ​process. ​However it can ​be removed by ​aerobic process.​ "

  4. From Thailand and case of Tapioca Plant and Ethanol Plant. I designed Modified Cover lagoon with settling pond and continue using SBR by endogenous phase operation the COD and BOD are around 200 and 60 respectively then we sent to Engineering Wetland that water can reach the std. But this treated waste water contain contains N, P, K (,50,50,100)and we try on Napier grass , Sugar cane, Cassava for water fertilizer and success untill we do not have the problem of treated WW at all. Wetland Engineering is right the Solution in term of academic but on application water fertilizer needed for the farmer.  aggasit2012@gmail.com

    1 Comment

    1. Are you currently looking for ways to reduce your COD and BOD even further? 

  5. Salient features of Anaerobic Treatment are as follows

    a. This mainly work on highly biodegradable waste water like Dairy, Sugar, distillary, starch manufacturing etc.

    b. Pre-treatment - Screen chamber, Grit chamber to remove floating and heavy inorganic compound. Equalization is also recommended

    c. It is combination of Hydrolytic, acidogenic and methanogenic bacteria. Methanogenic bacteria are slow growing.

    d. Colors from dyes can not be removed.

    e. Remaining organic matter are difficult to biodegrade by anaerobic process. However it can be removed by aerobic process.

    Rajendrakumar V Saraf