Scale up urea treatment for safe reuse of excreta (SuSan Design, Norway and Uganda)
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TOPIC: Scale up urea treatment for safe reuse of excreta (SuSan Design, Norway and Uganda)

Re: Scale up urea treatment for safe reuse of excreta - SuSan Design 26 Feb 2013 11:28 #3592

  • SuSan Design
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Hi Joe,

Jørgen did his masters (UMB) in cooperation with SuSan Design to review the risk levels at differet stages in the value chain we are planning from home to farm. The treatment time is dependent on temperature, urea use and needs to be followed to secure the deactivation of all pathogens. (log4 reduction)

We use the SLU research done by Nordin and Vinnerås. Based on teh good work Jørgen Fidjeland did at UMB for his masters he is now doing his phd research on this methodology at SLU.

In the pdf you will all find 1 page summaries of the reports we made during the test phase - we are ready for scale up.

Best regards,

Karsten Gjefle
SuSan Design
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Contact person Oslo:
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Contact person Nairobi:
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Last Edit: 26 Feb 2013 12:25 by muench.

Re: Scale up urea treatment for safe reuse of excreta - SuSan Design 26 Feb 2013 11:34 #3593

  • joeturner
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  • I am a shit philosopher, thinking about how we think about sanitation. I think our main paradigms in WASH may be wrong.
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log4 reduction of what, though?

According to Nordin's PhD thesis page 76, refering to Ascaris reductions:

If faecal material contains 1000
Ascaris eggs g-1 faeces wet weight (Schönning et al., 2007; Westrell, 2004), more than a 4 log 10 reduction may be required to reach the WHO product validation requirements


Have you met the WHO product validation standard?
I don't work for anyone, I am a philosopher interested to think about how we think about WASH and sanitation. All thoughts are mine alone, I am responsible for any errors.

Previously trained and worked as a Soil Scientist and worked on projects composting sewage sludge.

Re: Scale up urea treatment for safe reuse of excreta - SuSan Design 26 Feb 2013 11:40 #3595

  • christoph
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Dear Karsten,
thanks for answering. This post is related somehow as well to the terra preta posts.
Unfortunately your attachment has not come through, please attach it again.
You wrote:
The test unit in Kampala showed that under the curcumstances urea treatment gave pathogen free material and we did not get the same robustness of treatment from composting.

It would be very necessary to get some more specific information (which I guess is in the attachment).
The question which come up:

• Composting not so robust. As this puts a question mark on heat composting, I guess it is very important to be more than clear about the testing conditions. a) to be able to think if it was the way of use, b) the time of composting c) the experiment conditions or a general problem of composting. What has been your impression /conclusion?
• How did you do the pathogen analysis? A material and methods would be very helpful to be able to understand better. You wrote "pathogen free". That is a question I have. There has been quite a bit of discussion here and elsewhere that helminth eggs are very tricky. IF you don´t find them, it does not mean they are absent, you might just not have had them? or you might have a sample which was free. On the other hand you might find helminth eggs but they are dead...inactivated. So the treatment worked. I´m a civil engineer and my knowledge is just what I hear from others, but something does not seem right in the discussion.


Regards

Christoph

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Note by moderator (EvM): All of the documents about his grant which Karsten has attached or tried to attach are now available here in the SuSanA library:
www.susana.org/lang-en/library/library?v...p;type=2&id=1715
Last Edit: 26 Feb 2013 15:50 by muench.
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Re: Scale up urea treatment for safe reuse of excreta - SuSan Design 01 Mar 2013 15:22 #3682

  • Vinneras
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I just wanted to give some general comments to the previous discussion.

Composting is a complex system, the basics are easy but to reach a temperature that sanitises the material (>50° as a rule of thumb) is hard to achieve. To reach that temp in the centre is easy, but to reach a reduction of 4log10 (i.e. 99.99%) (irrespective of organism) you have to treat 99.99% of the material at high temp.
In the final material it is also hard to see any difference between cold and hot composted material. The method is a good method for stabilization and homogenization but not for sanitization.

Ammonia treatment is a simple and roboust method. The treatment needs to take place in a closed environment to avoid ammonia losses. The urea used for treatment both sanitize the material while at the same time increasing the fertilizing value of the material.
By adding the non-toxic chemical urea to a faecal material the enzymes therein transfer the urea into ammonia, that increases the pH to about nine and the sanitization starts.
The factors that regulate the speed of sanitization is the concentration of uncharged ammonia and the treatment temperature (that also increases the uncharged ammonia concentration). By changing these two parameters you can regulate the speed of the sanitiation.
In the case of Susan design, the study was performed as a BSc study with Enterococcus inactivation, this is a very conservative organism (our data indicate (not published yet) that it is more conservative than several viruses, including Adeno and reoviruses, at temperatures above 20°C).
The actual time of treatment can vary a lot, based on what ammonia concentration you have.
Below is a table summarising the effect of different organisms at different ammonia concentrations, as a rule of thumb with a safety margin, copied from a book chapter that is soon to be published(Vinnerås, B. 2013. Sanitation and hygiene in manure management. In: Sommer, S.G., Jensen, L.S., Christensen, M.L., Schmidt, T. (eds). Animal Waste – Recycling, Treatment and Management. Wiley-Blackwell. Oxford UK (In Press)).

Table 6.2. Time required for fulfilment of EU regulations on ABP (EC 146/2011) by chemical treatment of animal manure at different NH3 concentrations and at temperatures from 4 °C

Ammonia concentration [NH3] (mM) Salmonella spp. (days for 5 log10 redn.) Enterococcus faecalis (days for 5 log10 redn.) Ascaris spp.* (days for 3 log10 redn.)
50 4 150 200
75 1 80 150
100 0.5 50 100
150 0.5 30 80
200 0.5 20 60
250 0.5 10 40

*Data only given for inactivation at temperatures above 20 °C. The reduction in Ascaris spp. at lower temperatures is significantly longer, as the lag phase increases in time and there are not sufficient data for generalising the inactivation at this concentration.

With Higher temperatures the speed of inactivation is considerably faster as the effect of ammonia increases with temperature.

+++++++++++++++
Introduction of Björn (added by moderator):
Dr Björn Vinnerås in an Associate Professor in Environmental Engineering at the Swedish University of Agricultural Sciences and the National Veterinary Institute. Dr Vinnerås has during the last 15 years researched and developed sustainable sanitation systems for high as well as low income countries. His focus during later years has been sanitization technology and he has been developing ammonia sanitization techniques that has been implemented in the patented Single use, biodegradable self sanitizing toilet Peepoo as well as accepted by the Swedish Agricultural board as a recommended manure management method during disease outbreaks on farms.
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Last Edit: 03 Mar 2013 20:27 by muench. Reason: added intro about Björn
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Re: Scale up urea treatment for safe reuse of excreta - SuSan Design 01 Mar 2013 16:56 #3684

  • joeturner
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Thank you for taking the time to explain that to us, Bjorn. What is the ammonia concentration estimated to be inside the peepoo bags?

I disagree with you about co-composting, the method is robust, but only if the material is turned and mixed regularly. Hence I strongly do not believe anyone who says they can conduct full sanitising using co-composting in much less than 8 weeks without additions of extra C-rich material or without at least weekly turning. I don't think that can be done.

Are the figures you have given here measured or calculated? What concentrations did you need to have 3log10 reductions in 2-3 weeks, and how does that relate to the ammonia concentrations in the peepoo bags? Why would you not want to measure the destruction of the most conservative pathogen indicator available?

Why is the EU Animal Byproducts standard being used to test the effectiveness of a system in Uganda? Why is that relevant? Surely a 3log10 reduction may still give a result that is >1 ova per g as per the WHO recommendation if the pathogen loadings are high?
I don't work for anyone, I am a philosopher interested to think about how we think about WASH and sanitation. All thoughts are mine alone, I am responsible for any errors.

Previously trained and worked as a Soil Scientist and worked on projects composting sewage sludge.
Last Edit: 01 Mar 2013 16:58 by joeturner.

Re: Composting with hot box method (Howard-Higgins system) 10 Mar 2013 17:39 #3837

  • SuSan Design
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Dear Christoph and all others interested,

I stand by my comment as stated earlier: "The test unit in Kampala showed that under the circumstances urea treatment gave pathogen free material and we did not get the same robustness of treatment from composting." (log4 reduction was our goal)

This does not mean that I do not recommend the use of composting or the Howard/Higgins system. We have thoroughly evaluated and worked very closely with Richard Higgins.
For an urban context there are many waste streams and different solutions should be used to create a good mix in terms of capacity needed and the robustness needed.

Our experience shows very clearly that faecal sludge should be handled by ammonia treatment and other non-pathogenic waste streams like garden-, market-, household bio materials and agricultural bio waste/e.g. rice husks etc. can and should be composted. The Howard/Higgins methodology is valuable for this type of scenario. Urine from urinals can also be used here to bring some speed to the compost if that is available.

Bio materials that contain faecal matter from pits, septic tanks or UDDTs should be treated by our ammonia treatment methodology to assure safe reuse in agriculture.

See the set up we had in Kampala in the file attached - we are looking for scale up partners so do contact us if we can be of help to set up decentralized treatment units that are both cost efficient, robust and can run "off grid".

I hope this loosens up the annoyed part of your quest for information. Feel free to contact me for additional information.

Best regards,

Karsten Gjefle
Director
www.susan-design.org
Mobile: +47 410 422 75
Skype: karsten.gjefle
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Last Edit: 10 Mar 2013 17:55 by muench.

Re: Composting with hot box method (Howard-Higgins system) 10 Mar 2013 18:22 #3838

  • christoph
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Dear Karsten
Thanks for this very clear reply. Clarifying your standpoint. As sanitization of fecal matter is our main goal in this forum /this thread I think your statement is very important, as you are one of the few people to have direct contact with the system. I am rambling so much about this because from my understanding heat composting is the way forward and a bad example makes everything more complicated, but as well could serve for learning.
I think just the way of trying to get a heat composting going (14 days and boxes without moving) in the applied method is not good. But I would guess that details from your trials in Uganda could be very interesting for all of us who are thinking about heat composting. As Richard states…there is no doubt, that heat treatment is an effective way of treatment. So it would be very helpful to understand what caused the observation
did not get the same robustness of treatment from composting
.
It might be the point that the outer regions were too cold, or the heating up took not place, or time was too short, or was not continuous or the system does only work with sufficient other organic waste or, or, or. These findings would help us to avoid errors in the future and take short cuts as we don´t have to learn again.

Thanks again.

Christoph
Last Edit: 10 Mar 2013 19:11 by christoph.

Re: Composting with hot box method (Howard-Higgins system) 10 Mar 2013 19:05 #3839

  • christoph
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P.S. I only now saw the posting of Richard. Richard, I guess for most of us the helminth eggs are the (or one of the) most important aspect(s). Concerning the methods I recommend the thread about methods, especially this post#3669

Christoph
Last Edit: 10 Mar 2013 19:18 by christoph.

Re: Composting with hot box method (Howard-Higgins system) 11 Mar 2013 00:24 #3841

  • richard higgins
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The trials in Uganda were not conclusive as far as I am concerned.
As the trial was a one off batch,it was not sufficient to conclude what
I am trying to prove.

We only managed to do one cycle (batch)in the allotted time for the trial.
The 36 toilets added in bio liners were too many in one 1.5m unit so that
prevented the heat increase (also the plastic liners were all touching and
this prevented proper aeration)The same applied in the other units with too
closely packed bags. But the report that I received stated no harmful pathogens
were found upon testing.

The next trial I do will have obvious adjustments.
So this does not change anything for the potential of the HH - 2 system.
All our previous work for 15 years has given proper temperature increase,
which as our graph indicates on our presentation will kill all the harmful
pathogens and Ascaris eggs. Even though the temperature increase was not satisfactory due to these factors it remains evident that more capacity testing is needed and adjustments to the feed input have to be made.
This is what trials are all about.

Thank you for your patience.

Best regards

Richard

Fwd: video link for your presentation 19 Mar 2013 10:45 #3927

  • SuSan Design
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Dear all,

It might help to clarify some aspects of our research grant and the work we did in Kampala: The video of my presentation from the FSM2 Conference (end of October 2012 in Durban) is now available in the SuSanA Youtube channel.

Here is the link to the video of my presentation ("The sustainable sanitation design concept for sludge treatment for cities in Africa"):



The ppt slides to go with the video are available here:
www.susana.org/docs_ccbk/susana_download...sm2-gjefle-susan.pdf

I hope you find it interesting.

Regards,
Karsten
Contact person Oslo:
Karsten Gjefle, karsten@susan-design.org

Contact person Nairobi:
Emery Sindani, emery@susan-design.org
Last Edit: 19 Mar 2013 10:07 by muench.

Re: Fwd: video link for your presentation 19 Mar 2013 16:09 #3930

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Dear Karsten,

Thanks for the video and slides. I enjoyed watching your presentation!

Log4 pathogen reduction (99.99%) in 45 days is impressive. Kindly share with us the results of the tests of pathogen contents conducted by the Swedish University of Agricultural Sciences (SLU) as well as that performed by the national agricultural research team in Uganda (NARO). It would be interesting to see from these tests how the inactivation of pathogens especially helminth eggs (already raised by Christoph) changes during the treatment period of 45 days.
Were the faecal matter from dry toilets, septic tanks, and pit toilets treated separately? If yes, do the tests after treatment reveal any significant differences. Maybe the presentation of Björn Vinnerås on treatment efficiency that you referred to in your presentation answers these question. Please share this presentation if you have it: The treatment robustness from our treatment unit in Uganda has been verified by SLU and NARO in separate testing on pathogen and heavy metal levels.


Best regards,

Nelson
Nelson Ekane
Research Associate
Stockholm Environment Institute (SEI)
Kräftriket 2B
SE-106 91 Stockholm, Sweden
nelson.ekane@sei-international.org
www.sei-international.org
Tel: +46 (0) 8 674 7070
Mobile: +46 (0)737078631
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Scale up urea treatment for safe reuse of excreta (SuSan Design, Norway and Uganda) 26 Mar 2013 23:44 #4003

  • SuSan Design
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Dear all and Christoph in particular,

When I started working on the design of sanitation systems in 2007/08 I thought we would be composting as well and I was a big believer in the process until I understood the need of decentralization, bio volumes and long term heat levels to handle the pathogens.

When this did sink in I understood that my goals of reaching millions of users fast so SuSan Design could play a part in getting the 2,6 billion (or is it 4,1?) into a reachable goal "sanitation for all".

We need a bottle neck free system to handle the excreta from millions of people living in urban areas and the research developed by SLU and brought into a manageable concept for a treatment unit by SuSan Design has enormous potential to bring to reuse what today becomes pollution of groundwater and river/lakes.

The heavy metal volumes are the same as "fresh" excreta so very low. There should be no effluents from industry in the pits or private home septic tanks and surely not in the UDDTs. For risk levels to be low we have to be very vigilant about possible contaminants in pits or septic tanks in locations that use it for other waste volumes that can contain pollution.

I wish there was less talk and more investment. Gates Foundation was very generous to support this initial pilot that in my mind give a very clear working relationship between composting and ammonia treatment as I have explained earlier. Both methods are fantastic but play a different role in the waste management system for cities of the future.

(the current model of not doing anything or nutrient destruction is not a way forward)

Please read the comments of Bjørn Vinnerås as well...

Best regards,

Karsten Gjefle
SuSan Design
skype: karsten.gjefle
Contact person Oslo:
Karsten Gjefle, karsten@susan-design.org

Contact person Nairobi:
Emery Sindani, emery@susan-design.org
Last Edit: 27 Jun 2013 11:12 by muench.
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