Temperature Phased Anaerobic Digestion in Municipal WWTPs

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Does anyone have experience with temperature phased Anaerobic Digestion (TPAD)?

TPAD has many claimed benefits but I am wondering why there are only a few TPAD plants in the world, only few in USA, one in New Zealand, few in Europe. 

What are the disadvantages of TPAD?

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7 Answers

  1. The temperature.
    Above a threshold of T a degree actually evolve the system. 
    on this basis we must be careful.
    Each degree achieved will change the structure of the workplace. Each change will change the environment. Each evolutionary step is more manageable and no one is able to explain the consequences. Because he must not forget that the middle of the wastewater effluent is chemical. An issue that does not arise in an aerobic environment totally organic.

  2. Hello

    The anaerobic cannot exist on Earth

    How was born the State without oxygen?

    A perception of mind of a person discovering an environment in a State of putrefaction advanced whose knowledge of the time (the beginning of the science of life in the 1700/1800, cannot it give a definition and as opposed to aerobic, a State) designated without oxygen (anaerobic) in contrast.

    At that time we just discovered the aerobic State and the scientific community welcomed his vision of opposition.

    Except that the knowledge of recent items contradict this definition:

    a) Water, H2O contains oxygen. Where there is water there is thus necessarily oxygen. Even if there are 0.001%.

    b) The atmosphere is totally aerobic at several levels of its layer where it is demonstrated that there is life. The percentage of oxygen in Earth's atmosphere is about 21% in proportion. Percentage which decreases, is scarce, but is always present.

    c) Those who speak of the anaerobic describe an environment often inaccessible and distant in the remotest places of our planet, where it is of course impossible to check.

    d) Some describe this environment to clean up wastewater.

    he land is mainly managed in its entirety by the presence of oxygen. For a State without oxygen to take place it would have exceptional conditions such as:

    - The containment of an environment protected from the air with oxygen

    - An environment that is totally waterproof, which does not exist on our planet

    - Water with formula H2O loses its 2 molecules of oxygen

    - Hundreds of years to stabilize the environment

    - Bacteria mutate to live without oxygen

    - Bacteria that will perpetuate

    All of the following elements contradict the establishment of a State without oxygen.

    The environment must not be destroyed all 3/5 days as is the case on a wastewater management station or, in a complex of biogas in which we did get oxygen (water, air, organic matter containing water H2O). Except that it's hard to admit that in a medium containing water, so an aerobic State with oxygen, can settle an anaerobic State without oxygen. 

    question

    - How does this environment to settle?

    - How does this environment persist?

    - What is the trigger for the creation of the State?

    - How and who would be able to delineate in an aerobic oxygen environment, the component of the separating barrier of the aerobic State with the anaerobic State, in a moving liquid?

    - Is it an intermediate state between these two circles?

    - By the principle of the existing atmospheric conditions on Earth, water and air are in perpetual motion. Because of this principle oxygen is regenerated at all times even in the remotest corners of our land. An effluent of sewage on a wastewater management station transits within five days.

    The anaerobic: a heresy, a utopia, a challenge, a lie, a farce, a mistake, etc. What surprises most of our days with very advanced technical knowledge on the science of life on Earth is to see how our scientists are struggling to correct erroneous principles. 

     

  3. Most prefer aerobic. Still the degree of uncertainty of having one pathogenic microbe competing with another pathogenic microbe leaves you with the more resilient microbe surviving. It might become helpful to stick with a non pathogenic RNA microbe. This will speed up the process and many other benefits.

  4. There are several papers available on the performance of a TPAD facility in Pamplona, Spain along with performance data and design criteria used. I saw the plant when I was in Spain back in 2010 and was very impressed with quality of the effluent and digestion of the biosolids reduction of VLSS.

  5. Sam, we did a comparison on mesophilic, TPAD, thermophilic operating  conditions on a live plant in Scotland. We ran a trials to identify the benefits with regard to biogas production, and log reduction of E-coli. If the drive is to increase gas production, we did not see a significant difference, especially when you consider the additional energy required to maintain >50 Degrees C. However if the driver is sludge stabilization and greater reduction of E-coli the in higher temp allowed us to meet our land application requirements. We had no issues with foaming of the digester when ramping up or reducing the temperatures. The main downside with TPAD in my view is exactly why you are asking the question, it is not as established and understood process, thus a certain amount of scepticism of it. I would stick with either meso or thermo as your conditions dictate to keep it simple.

    1 Comment

    1. Hi Paul ,Thanks for the answer. I myself involved in one of the TPAD commissioning project these days and system is working well so far and reduce risk of foaming with more VSD reduction is something we expect also with less HRT requirement compared with Meso. It would be difficult to stop being sceptical about this process unless it is proven in many installations. 

  6. At Carimate (Como, Italy) there is a working example. Contrary to many other cases, they operate a first stage mesophilic (fed on sewage sludge) and a second thermophilic stage, fed on biodegradable liquid wastes. As these wastes do not require heavy hydrolysis to be degraded, and due to the over-sized digester, the process  runs steadily with a very good production of biogas (70% methane). You may ask more info at: responsabile.tecnico@sudsevesoservizi.it (ing. Marco Bernasconi; warning: he does not speak/write in English). Website (in Italian): http://www.sudsevesoservizi.it/Objects/Home1.asp

    1 Comment

    1. Hello

      In an effluent of sewage containing the chemical presence of micro organisms is rare. otherwise it would be super bacteria (we do not know yet) The sludge of wastewater management stations excrement died inert.The mud is a State of decomposition of the organic matter under the action of methanisation.This environment contains more of being alive.It is difficult to conceive that human beings alive can survive in these conditions. Sludge management stations feces contain 8% of dead bacteria. Below a certain level of presence of micro organisms they survive but can no longer operate the feature of biodegradation of organic matter.In addition there are micro organisms live in a medium containing water.Off the sludge out of the wastewater management stations are dried on planks of sandy earth before being stored on a holding of the follow-up of their management area. It is imperative to dry sludge or the action of methanisation would survive on their storage making implode in permenence storage. In these dry sludge there is no sign of life of a any micro-organism. The description above applies to the term mesophilic as for the term thermophilic. It's amazing the ingenuity of people in sanitation to believe in something that is completely unrealistic. This presentation is so utopian.

  7. From experience it boils down to economics and process simplicity. The thermophilic process requires unique parameters that are fairly difficult to maintain. In our designs we stick to pure thermophilic as a secondary mesophilic process add few economical (read $) benefits to the equation.