SuSanA - Forum Kunena Site Syndication http://forum.susana.org/ Fri, 19 Dec 2014 08:39:20 +0000 Kunena 1.6 http://forum.susana.org/components/com_kunena/template/default/images/icons/rss.png SuSanA - Forum http://forum.susana.org/ en-gb Re: Pathogen destruction in biogas plant vs ABR - by: MichaelCarr http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/10926-pathogen-destruction-in-biogas-plant-vs-abr-anaerobic-baffled-reactor#11412 http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/10926-pathogen-destruction-in-biogas-plant-vs-abr-anaerobic-baffled-reactor#11412 From what I know, the HRT - Hydrolic Retention Time in a BGD is 40 days.
Farmers here in Cambodia are instructed to mix 1 for 1 - ie; one gallon of cow poo for one gallon of water. They dry the ensuing sludge in beds, but I haven't been able to see any empiric info on safe UV drying times.

Due to the one on one poop v water situation - adding a flush toilet to the system - which farmers in the provinces aspire to - creates a problem of too much water entering the BGD and breaking down the system. Anybody any ideas on how to overcome this? Is there some kind of intervention that already exists?

best regards
Mike]]>
Biogas sanitation systems and DEWATS Fri, 19 Dec 2014 03:40:35 +0000
Lessons Learned from the Dissemination of Biodigesters for Sanitation in Haiti, from 2010 to 2013 - by: Anthony http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/11396-lessons-learned-from-the-dissemination-of-biodigesters-for-sanitation-in-haiti-from-2010-to-2013#11396 http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/11396-lessons-learned-from-the-dissemination-of-biodigesters-for-sanitation-in-haiti-from-2010-to-2013#11396
It is with great pleasure that we share with you on the SuSanA Forum our research report “Lessons Learned from the Dissemination of Biodigesters for Sanitation in Haiti, from 2010 to 2013”.

The entire document may be viewed here:

www.dropbox.com/s/8qqu3qpkhohatol/NCA_Bi...20report_EN.pdf?dl=0

An extract from the document translated into French, may be viewed here:

www.dropbox.com/s/jaq3m8dehbqmotg/NCA_Bi...0Extract_FR.pdf?dl=0

The report is the result of a research into the dissemination of biodigesters for sanitation in Haiti in the period 2010 – 2013. The research was carried out by Norwegian Church Aid (NCA) from September to December 2013. The overall purpose in carrying out the research was to evaluate the functionality of biodigesters and their toilets up to 4 years after their construction. The evaluation was based upon the 3 objectives that the biodigesters were designed to address:

• Sanitation (i.e. toilets, wastewater treatment and pathogen removal); 

• Renewable energy (in the form of ‘biogas’); and 

• Nutrient rich digestate (in the form of ‘biol’).

We encourage all forum users with a particular interest in biodigesters, Faecal Sludge Management, DEWATS, or indeed Haiti, to read the report and provide feedback.

A more in depth technical analysis of the report’s findings, will be presented at the 3rd International Faecal Sludge Management Conference in Hanoi, Vietnam, during the podium session on Anaerobic treatment on Tuesday the 20th January 2014. To all interested conference delegates, we look forward to seeing you there.

Finally, may we take this opportunity to wish all Forum users a Merry Christmas and a safe, healthy, sustainable, and joyous 2015!

With festive regards,

The NCA WASH team in Haiti.]]>
Biogas sanitation systems and DEWATS Wed, 17 Dec 2014 17:07:16 +0000
R&D-Idea: Combination of SIMPLE Anaerobic with SIMPLE Aerobic system - by: AquaVerde http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/11361-rad-idea-combination-of-simple-anaerobic-with-simple-aerobic-system#11361 http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/11361-rad-idea-combination-of-simple-anaerobic-with-simple-aerobic-system#11361
ABR is just a purposely simplified "permanent plug-through 2-3 stage biogas-reactor" useful as 1. stage for agriculture and sewage.

R&D-Idea: Combination of SIMPLE Anaerobic with SIMPLE Aerobic system

a cross-border cooperative and public R&D (Creative Commons = Open Source for all! "...to share the results and have more means to perform the research...") Therefore, no large scale PPP's and private R&D-institutes!

A combination of a simplified USAB with CW's. This means a "COLD" Anaerobic Baffled Reactor (ABR) with a Dr. Käthe Seidel 2 stage CW-System (now called "French" CW-System) for combined sewer systems (sewage and storm-water combined).
During storm-water mineralised and fresh sludge will get purposely partly flushed out of ABR by design to 1. Stage of CW-system. In front of ABR is a Rainwater Divider placed, which prevents against total flush outs of all sludge from ABR during heavy rains by design. All Rainwater from Rainwater Divider and all effluent & all sludge (mineralised and fresh) from ABR (all ground-outlets + overflows) leads to the 1. Stage of CW (a rough CW stage for sludge mineralisation).

In my opinion this leads to a smaller footprint (I guess: 1,5-2 m2/pe) of following two stage "French" CW-System and will enable to make use of the permanent incoming carbon. I guess only a wwtp scale above 200-300 pe will be an economical plant, with this combined intention in mind.

ABR is feeding gas through a active carbon biogas cleaning to a Stirling CHP or goes simple/straight to a robust gas-therme to produce heat only. (wwtp-CHP-stirling example by Dr. Heinrich in Niederfrohna, ZV Frohnbach www.niederfrohna.de/?q=node/750)

Maybe, 2 x SIMPLE = very complicated "self-cleaning power of nature" !?
To be more clear, the only aim of this planed "Simplicity" (low-tech), is a planed higher Resilience/Robustness/Effectiveness of an AN-AER-wwtp-sytem, even if Efficiency is less and volumes are higher in comparison to other wwtp's. E.g., in a first stage of suggested R&D a CHP-stirling should not be part of the focuses, much later yes.

This R&D should not be limited to very technological issues only. It should involve as well implementation and possible desamination via appropriate flexible business models. And should therefore involve interested PUBLIC utilities too. Because, technology by itself is "stupid" and do not know by it self, how useful it is for others.

Looking forward to your reply's.

Detlef]]>
Biogas sanitation systems and DEWATS Sun, 14 Dec 2014 15:40:43 +0000
Re: Pathogen destruction in biogas plant vs ABR (Anaerobic Baffled Reactor) - by: christoph http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/10926-pathogen-destruction-in-biogas-plant-vs-abr-anaerobic-baffled-reactor#11356 http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/10926-pathogen-destruction-in-biogas-plant-vs-abr-anaerobic-baffled-reactor#11356
ABR is aimed to Wastewater treatment a) desctruction of organic material by anaerobic digestion (and by that produces biogas) b) separation of liquid fase and settable material.

The biogas plant is (as the name says) aimed to biogas production (and therefore reduction of organic material) but as Krishan wrote the aim is not to separate the liquid fase and the settable material, as typically the complete content should be put to agricultural use.

So for a normal biogas plant I would say – as there is no separation of sludge and water the efficiency for pathogens should be less than in an ABR. But as I said two different functions!

Yours Christoph]]>
Biogas sanitation systems and DEWATS Sat, 13 Dec 2014 20:07:52 +0000
Re: Pathogen destruction in biogas plant vs ABR - by: JKMakowka http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/10926-pathogen-destruction-in-biogas-plant-vs-abr-anaerobic-baffled-reactor#11352 http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/10926-pathogen-destruction-in-biogas-plant-vs-abr-anaerobic-baffled-reactor#11352 muench wrote:

How much solids-liquid separation would we expect in a biogas reactor? Probably not so much. Would the helminth eggs nevertheless settle to the bottom of the reactor and into the thicker part of the sludge that stays in the reactor for a very very long time (even "indefinite"?)?


This depends in the design, but usually there is no seperation as the digesters are either actively mixed / plug-flow designs, or at the very least try to minimize "dead space" where solids could settle.

It would be possible oft course to design a hybrid ABR that tries to optimize pathogen reduction and also produce Biogas to some extend.]]>
Biogas sanitation systems and DEWATS Fri, 12 Dec 2014 15:02:55 +0000
Re: Pathogen destruction in biogas plant vs ABR (Anaerobic Baffled Reactor) - by: joeturner http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/10926-pathogen-destruction-in-biogas-plant-vs-abr-anaerobic-baffled-reactor#11350 http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/10926-pathogen-destruction-in-biogas-plant-vs-abr-anaerobic-baffled-reactor#11350
If so, then this might also come down to how well the helminth survive in a wetter environment in the one than in the other. Also, presumably, there is more of a build up of methane in the biogas than in the ABR, so the helminth survival might (or might not) be affected by that.]]>
Biogas sanitation systems and DEWATS Fri, 12 Dec 2014 14:35:47 +0000
Re: Pathogen destruction in biogas plant vs ABR - by: muench http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/10926-pathogen-destruction-in-biogas-plant-vs-abr-anaerobic-baffled-reactor#11349 http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/10926-pathogen-destruction-in-biogas-plant-vs-abr-anaerobic-baffled-reactor#11349
And yes, you are right: When I was talking about helminth eggs, I was thinking of the sludge. As these helminth eggs are relatively heavy, they would settle out in the sludge.

All wastewater treatment processes produce an effluent and a sludge - the latter is often forgotten about which is not good.

So you are right with regards to the effluent from the ABR, the helminth eggs should not be a concern, but rather the other pathogens (bacteria, viruses, protozoa) need to be looked at.

How much solids-liquid separation would we expect in a biogas reactor? Probably not so much. Would the helminth eggs nevertheless settle to the bottom of the reactor and into the thicker part of the sludge that stays in the reactor for a very very long time (even "indefinite"?)? - Help! Where are the biogas digester experts on this forum?

Regards,
Elisabeth]]>
Biogas sanitation systems and DEWATS Fri, 12 Dec 2014 14:26:27 +0000
Re: Pathogen destruction in biogas plant vs ABR - by: joeturner http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/10926-pathogen-destruction-in-biogas-plant-vs-abr-anaerobic-baffled-reactor#11348 http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/10926-pathogen-destruction-in-biogas-plant-vs-abr-anaerobic-baffled-reactor#11348 Biogas sanitation systems and DEWATS Fri, 12 Dec 2014 13:59:08 +0000 Re: Pathogen destruction in biogas plant vs ABR - by: joeturner http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/10926-pathogen-destruction-in-biogas-plant-vs-abr-anaerobic-baffled-reactor#11347 http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/10926-pathogen-destruction-in-biogas-plant-vs-abr-anaerobic-baffled-reactor#11347
Anaerobic baffled reactor



Biogas reactor



from Akvopedia]]>
Biogas sanitation systems and DEWATS Fri, 12 Dec 2014 13:54:20 +0000
Re: Pathogen destruction in biogas plant vs ABR - by: muench http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/10926-pathogen-destruction-in-biogas-plant-vs-abr-anaerobic-baffled-reactor#11345 http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/10926-pathogen-destruction-in-biogas-plant-vs-abr-anaerobic-baffled-reactor#11345
I think your assumption is correct:
I can only assume that this is because biogas plants may usually have longer retention times.


Biogas plants have much much longer retention times than ABRs (many days compared to just hours or a few days).

Perhaps another reason could be that biogas plants can be operated at higher temperatures which would also lead to faster pathogen kill.

One publication that came to mind (because I was involved in creating it) is this Technology Review of GIZ on biogas plants:

Mang, H.-P., Li, Z. (2010). Technology review of biogas sanitation (draft) - Biogas sanitation for blackwater, brown water or for excreta and organic household waste treatment and reuse in developing countries. Deutsche Gesellschaft für Internationale Zusammenarbeit GmbH (GIZ)
www.susana.org/en/resources/library/details/877

There is a section in there on pathogen destruction, I copy a bit:

3.2.1 Incomplete pathogen removal

Human excreta are contaminated with all kinds of pathogens
and hence a reliable technology is necessary for their
inactivation. During anaerobic digestion an inactivation of
most animal and plant pathogens is obtained under
thermophillic conditions (>55°C for several days). Several
studies on wet fermentation report that also mesophilic and
lower temperature operation inactivates pathogens; further
findings indicate that reactors with retention times of at least
60 days at 20oC to 15 days and 35-55oC reduce significantly
any type of pathogens (Michael H. Gerardi 2005).

Many studies reveal also that under fully mixed mesophilic
conditions, pathogens are not completely inactivated.
Therefore recommendations on the use of the not posttreated
slurry should limit irrigation only to fruit trees, and
exclude spray irrigation to vegetables. Effluent water could be
post-treated with UV desinfection by natural sunlight in
shallow polishing ponds. Post-composting of sludge may be
required for a one year period. If the effluent is directly
worked into the soil as soil conditionner no further restriction
applies.

Two main factors regulating the inactivation of pathogens
have been identified, namely the temperature and the concentration
of free ammonia as a function of the time of treatment/
exposure.




When it comes to helminth eggs (my most favourite topic), then I think they are pretty much just settled out but not destroyed in biogas plants. I could not imagine which mechanism should destroy them in a biogas plant given that they are so hardy that they can survive in the digetive tract of humans? (about helminths: en.wikipedia.org/wiki/Helminths - another page that I have been working on).

So when the sludge from a biogas digester is used for reuse activities you still need to keep those helminth eggs in mind and put treatment steps in place (or other safety precautions during reuse).

There is also this presentation from Heinz-Peter Mang about reuse of digestate in China which is very interesting:

forum.susana.org/forum/categories/174-sa...fertilizer-bioslurry

Perhaps my little input here will prompt others to share their experiences (or questions) on this important aspect of pathogen destruction in biogas sanitation systems.

And how about yourself, Marijn: As you work on a biogas programme in Nepal, what are your experiences with pathogen destruction in biogas plants, and reuse activities? Or is your work not dealing with human faecal matter?

Regards,
Elisabeth]]>
Biogas sanitation systems and DEWATS Fri, 12 Dec 2014 11:30:40 +0000
Re: WRC Publication: DEWATS Process for Decentralised Wastewater Treatment - Technical Lessons From eThekwini Municipality - by: biotech80 http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/9332-wrc-publication-dewats-process-for-decentralised-wastewater-treatment-technical-lessons-from-ethekwini-municipality#11195 http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/9332-wrc-publication-dewats-process-for-decentralised-wastewater-treatment-technical-lessons-from-ethekwini-municipality#11195
sorry for the late reply on your questions.

First, we do not measure colour of the wastewater. As we only treat domestic waste water we do not see any strong colouring. No dyes are in the waste water either.


I attach a picture pf the waste water sampled throughout the DEWATS plant, so have a look at it.


Regarding VGF HGF:

Sadly, both PGFs are connected in series, so we do not have a parallel comparison of each PGFs treatment. However, the VGF performs very good, yet, due to undersizing it, it is not meeting effluent discharge values for South Africa. A COD of below 100 mg/l is give ant any time though...as well as removal of TSS,turbidity and odour.


IF it would help you I could run the standard 3/5 point colour spectrum.

EDIT:

We do not capture biogas as it wasnt possible to get the settler gas tight. Additionally we experienced overboearing scum/Fog issues making it necessary to weekly open and access the manholes for maintenance.



Regards
Bjoern]]>
Biogas sanitation systems and DEWATS Mon, 01 Dec 2014 06:39:14 +0000
Re: WRC Publication: DEWATS Process for Decentralised Wastewater Treatment - Technical Lessons From eThekwini Municipality - by: biotech80 http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/9332-wrc-publication-dewats-process-for-decentralised-wastewater-treatment-technical-lessons-from-ethekwini-municipality#11194 http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/9332-wrc-publication-dewats-process-for-decentralised-wastewater-treatment-technical-lessons-from-ethekwini-municipality#11194

let me try togive an answer on your question.

I am the BORDA R&D Coordinator and a PhD student with Prof Buckley in Durban. I am conducting my research on the DEWATS demonstration plant you/Chris mentioned.


To your question:

The main COD reduction usually happens in the first 3 Anaerobic Baffled Reactors. A second degradation of about 10% COD happens in the first following Anaerobic Filter.
This can be seen in most BORDA plants around the world.


A probably high degradation is happening in the settler before the reactors, but, at the moment, cannot be sampled and analyzed.
Originally we tried to collect the biogas from the settler, but issues with pressure builtup and scum removal made this impossible.

I am saying COD reduction as we cannot measure the actual gas production in the reactors.
It also appears that a certain higher portion of the gas is not leaving the liquid phase but carried over to ABRs at the end.

If you have any further questions...i am happy to answer.
Sadly, I cannot share data as publication is the first step.
Attached find a graph with the results of 2 samplings of the reactors.

Additionally, to illustrate what is meant with scum in this context a short video I made of the !weekly! descumming procedure. Scum is meant in the terms of floating Fat, Oil & grease matter containing larger amounts of gasbubbles.




All the Best
Bjoern]]>
Biogas sanitation systems and DEWATS Mon, 01 Dec 2014 06:13:18 +0000
Re: The potential for financing small-scale wastewater treatment (with UASBs) through resource recovery: experience from Bocas del Toro, Panama - by: stilmans http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/10860-the-potential-for-financing-small-scale-wastewater-treatment-with-uasbs-through-resource-recovery-experience-from-bocas-del-toro-panama#11045 http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/10860-the-potential-for-financing-small-scale-wastewater-treatment-with-uasbs-through-resource-recovery-experience-from-bocas-del-toro-panama#11045
Unfortunately, my understanding of the copyright agreement with the publisher is that I am not authorized to distribute the article in whole or in part on other venues. I realize that this is inconvenient, but I was not in a position to pay the higher publication fees for open access.

I do believe I am authorized to share individual copies of the article to colleagues for their personal use...]]>
Biogas sanitation systems and DEWATS Wed, 19 Nov 2014 06:44:53 +0000
Re: Ammonium in effluents of decentralised treatment plants - by: Bhaskar http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/2159-ammonium-in-effluents-of-decentralised-treatment-plants?limit=12&start=12#11030 http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/2159-ammonium-in-effluents-of-decentralised-treatment-plants?limit=12&start=12#11030 Arctic - www.windows2universe.org/earth/polar/arctic_marine_life.html
Antarctic - blogs.jcvi.org/tag/diatom/
Lake Erie - www.sciencedirect.com/science/article/pii/S0380133011002619

Diatoms are 'plants' not animals. They only consume the nutrients in the sewage.

Our process is so simple that you do not have to harvest the Diatoms, you can allow them to die and sediment.

Or you allow them to flow out with the treated sewage, the Diatoms would be consumed by the fish in the receiving waters. This is better than allowing nutrients to flow out, this only causes unwanted algae such as Cyanobacteria to bloom.

Farmers use manure to grow crops.
ec.europa.eu/programmes/horizon2020/en/n...king-most-pig-manure
"Traditionally, farmers disposed of this mix of urine, faeces and waste water by simply spreading it on the ground as fertiliser."

So what is the problem in growing algae in sewage and allowing fish to feed on the algae?]]>
Biogas sanitation systems and DEWATS Tue, 18 Nov 2014 11:29:17 +0000
Re: Ammonium in effluents of decentralised treatment plants - by: kelldigest http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/2159-ammonium-in-effluents-of-decentralised-treatment-plants?limit=12&start=12#11028 http://forum.susana.org/forum/categories/35-biogas-sanitation-systems-and-dewats/2159-ammonium-in-effluents-of-decentralised-treatment-plants?limit=12&start=12#11028
How are the diatoms harvested and used?

In Europe you cant feed animals to animals that have been fed on human waste(sewage).

Regards
Seamus.]]>
Biogas sanitation systems and DEWATS Tue, 18 Nov 2014 10:34:56 +0000