Extended Aeration Activated Sludge (EAAS) Treatment System Design

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Hi everyone:

I'm looking for a handbook to design EAAS treatment system. Does anyone have any reference to give or introduce me to?

It's very important to me.

Thanks

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6 Answers

  2. I agree that Metcalf and Eddy is the standard reference for the industry. However it covers an extremely wide range of subjects. I have attached a report by the South African Research Commission written by Prof. George Ekama et al. This report was extremely helpful in my career. If one works though this report it will give you a very good understanding of the EAAS process and positively assist with the design of such a system.

    1 Comment

    1. First of all thanks because of your reply. but i have seen metcalf before and I did not find anything related to EAAS design. Is it completely similar to conventional activated sludge process?

       

      1 Comment reply

      1. Hi Iman. To my understanding it is essentially the same thing and the same design principles apply, except for the differences below. I find that sometimes there are different understandings of EAAS.  The only difference is that conventional AS could typically have primary settling tanks upstream to remove part of the organic load and operate at lower sludge ages and retention times. EAAS typically do not use primary settling tanks (and are therefore simpler) and is typically designed for longer sludge ages of 20 to 30 days, with hydraulic retention of 24 hours or more.

        Regards

  3. Bonjour Iman 

    ton post présente quelques petites imperfections.

    Boues activées????

    Traitement ?????

    Aération prolongée???

    Il n’existe aucun traitement des boues par aération prolongée. l’aération prolongée ou l’aération tout court est le mécanisme d’aération qui détermine de l’activation des boues.

    Je m’explique

    Dès l’arrivée de l’effluent sur le site terminal de gestion, ce dernier passe dans un bac d’aération. il s’agit d’une visse sans fin qui injecte de l’air jusqu’au fond du bac d’aération.

    Existe t-il un traitement ? NON, il s’agit uniquement de tuer le processus  de méthanisation de l’effluent. A la base de la conception des stations l’enclenchement du processus de méthanisation de l’effluent fissurait le béton de construction des bacs. En aérant le bac par une visse sans fin, on tue le processus de méthanisation.

    Pour labéliser ce processus, les techniciens ont eu l’idée de le revaloriser sous une forme -biologique- d’un éventuel traitement de l’effluent, ce qui n’est pas du tout le cas.

     

    Boues activées

    toute la matière en suspension dans l’effluent se transforme en boue dès qu’elle perd ses caractéristiques -biologique- souvent du à :

    - défaut d’oxygène

    - molécules chimiques

    C’est souvent effectivement de la boue qui arrive sur le site de gestion des eaux usées. Cette boue n’a plus rien de -biologique-, c’est un élément mort, inerte. C’est pour cette raison que mondialement, les stations de gestion produisent annuellement plus de 45 millions de tonnes  de résidus boueux.

    la boue est indestructible -biologiquement- parlant.

    Avant d’être de la boue c’était de la matière organique en majorité de la matière fécale baignant dans un liquide imprégné d’urine. Une urine qui au contact de l’oxygène transforme l’urée en ammoniaque.

    Tous les composants biochimiques de l’urine, ajoutés aux molécules chimiques des produits détergents et brassés par le bac d’aération  font un liquide hautement toxique.

    La boue activée est donc uniquement de la boue brassée par une visse sans fin qui ne lui apporte rien autrement qu’augmenter la toxicité du milieu par la présence d’une forte dose d’oxygène.

     

    Le traitement est fantomatique puisqu’en sortie malgré plusieurs étapes du dispositif de la station il y a autant de boue à la sortie que celle qui y est entrée.

    Seuls les micros organismes peuvent réduire, voir supprimer la matière organique en suspension mais dans les boues ils sont morts. Les boues d’assainissement contiennent plus de 8% d bactéries mortes.

    Une hérésie puisque naturellement une bactérie morte cela n’existe pas.

     

    L’action prolongée du système d’aération des boues est inutile du moment que le liquide est devenu neutre inerte. l’aérer durant des heures augmentera le coût énergétique de la gestion des eaux usées sur le site terminal.

  4. Hello Iman your post presents some small imperfections.

    Activated sludge????

    Treatment?????

    Extended ventilation???

    There is no treatment of sludge by prolonged aeration. Prolonged aeration or short aeration is the aeration mechanism that determines the activation of the sludge.

    I explain

    As soon as the effluent arrives at the management terminal site, it passes through an aeration bin. This is an endless screw that injects air to the bottom of the aeration bin.

    Is there a treatment? No, it is only a matter of killing the process of digestion of the effluent. At the base of the design of the stations the initiation of the digestion process of the effluent fissurait the concrete of the construction of the bins. By aerating the tray by an endless screw, the process of digestion is killed.

    To label this process, the technicians had the idea of upgrading it in a form-biological-of a possible treatment of the effluent, which is not at all the case.

     

    Activated sludge

    All suspended matter in the effluent is transformed into mud as soon as it loses its characteristics-biological-often from:

    -Oxygen deficiency

    -Chemical molecules

    It is often actually mud that arrives at the sewage management site. This mud has nothing more-biological-, it is a dead element, inert. For this reason, globally, management stations produce more than 45 million tonnes of muddy waste annually.

    The mud is indestructible-biologically-speaking.

    Before being mud it was organic matter mostly of fecal matter bathing in a liquid impregnated with urine. A urine that in contact with oxygen transforms urea into ammonia.

    All the biochemical components of the urine, added to the chemical molecules of detergent products and brewed by the aeration tray make a highly toxic liquid.

    The activated mud is therefore only mud brewed by an endless screw that does not bring anything other than increase the toxicity of the medium by the presence of a high dose of oxygen.

     

    The treatment is ghostly since in spite of several stages of the station's device there is as much mud at the exit as the one that entered it.

    Only micro organisms can reduce, see remove the suspended organic matter but in the sludge they died. Sewage sludge contains more than 8% of dead bacteria.

    A heresy since naturally a dead bacterium does not exist.

     

    The prolonged action of the sludge aeration system is useless as long as the liquid has become inert neutral. Aerating it for hours will increase the energy cost of wastewater management at the terminal site.

     

     


     

  5. Metcalf&Eddy Wastewater Engineering McGraw Hill is a book that gives You good info on all the subjects in wastewater tretment as Jeremy advised,

    1 Comment

    1. First of all ​thanks because ​of your reply. ​but i have seen ​metcalf before ​and I did not ​find anything ​related to EAAS ​design. Is it ​completely ​similar to ​conventional ​activated ​sludge process? ​

  6. There are simple guidelines in the standard text books - Metcalfe & Eddy being the most obvious.

     

    You can then evaluate the resulting design using computer models, including varying flow / load / storms & sensitivity to settlement assumptions.