The question is probably more difficult than I state it now, but we are missing the management model and the support of governmental structures to support the development of such systems.

...

A lot of gas can be produced from FS if the management system motivates the operator.

I guess I tried to answer your question from July ahead in Feb 2014 already

Kindly see: forum.susana.org/forum/categories/97-ena...mit=12&start=12#7358

Maybe answers are too simple and too much profit orientated!?

All the Best
Detlef

Dear all,

thanks for the nice discussion.
The topic about bio gas generation from septage or FS from pit latrines as well as bio gas potentials of substrate is a topic that is a crucial topic if we try to generalize it.
To get some practical experiences in this discussion I will try to clarify in the name of BORDA on the questions raised about sufficiant biogas productiion and economic viablity of FSM Services that use biogas for additional income generation.

1. Biogas production from septage or FS:
Yes, there is still "sufficiant" biogas that can be generated from FS or septage. Please find attached the report of a monitoring project which BORDA conducted for a FS Treatment plant in Lusaka, Zambia. 15m³biogas per 1m3 FS. With a input of approx. 1.6m3/day. Sludge samples form that region (high water table) show that sludge average TS and TVS are: TS=15% , TVS=37% (270l Gas/kgTVS). The TVS is quite low compared to sludge samples from Antananarivo, Madagascar (TVS>60%), where we are working with WSUP on two FSM projects. However TS in Antananarivo Region is at TS:10%. This evens out TS/TVS ratios (Lusaka:5.6 and Tana: 6.0).
The high TS in Lusaka is achieved, because pit latrine construction is majorely done over ground, because of the high water table. That creates a very dry FS.

The first point I would like to make is that even though sludge conditions are quite different and might indicate at first that it is fully digested they still produce biogas. How much is a question of the operator and how it is fed. The FS or septage are great for the stabalization of the anaerbobic food chain. If we look at biogas plants in Germany each biogas plant fermentation is considred to be unique. Still construction parts are standardized. Therefore the essential part is the operation. A biogas plant need lots of attention if we want to maximize resource recovery, This should be the same if we look at biogas generation from anaerobic treatment in FSM.

2. The projects Mr. Schwagerer brings up especially in Mojekerto, BORDA faced problems in terms of operation. With 30 m3/d it is quite big compared to the plant in Lusaka. For bigger treatment plants infrastructure becomes even more essential. Mojokerto handed over to the Municipality in 2010 and by now it is only receiving 3-6 m3/day FS from septic tanks. This is not sufficient for a proper treatment process. I have no gas values but I can assume that it is as well not sufficient. Again this brings up point of economic viability... or the question why is there no operator who is interested to get the treatment plant running to generate more income from resource recovery. The question is probably more difficult than I state it now, but we are missing the management model and the support of governmental structures to support the development of such systems.

The amount of risks for the planning process is quite high, so many unknowns (nothing new:). However, the operator and the management model and how it is introduced into the public private context is essential. We need more show cases that can convince other municipalities and we need trainings for operators that help them understand impact of substrates and other O&M procedures.

A lot of gas can be produced from FS if the management system motivates the operator.

BR
Thomas

Dear All

Biogas generation from septage from septic tanks does not appear feasible as they are in almost degraded form due to long retention time in septic tanks. Therefore, Biogas production rate from septage should be very low.
There are two references for septage management in Indonesia- Banda Aceh and Mojokerto Cities by BORDA. They were implemented a few years before.
There is no information about the performance of these two units, on the site of BORDA. If such information is available to any member of the Forum, I would like to have it.
Regards
Pawan

Thanks Linda,

If you are interested for field testing, you may consider our project area in Bangladesh.

Great question Roshan!

How do we get research into practice? Based on this research, I think it is important to point out the importance of doing a market demand study first to identify the best end-use. There are not currently any standaridized methods for doing this, but it is something we are also working on and hope to field test before the end of the year.

Dear Linda and dear Mbaye,

First of all I do not call my self FSM-expert! I apply just common sense.

Still I was puzzled to read in your comprehensive FSM-article at 3.4 Biogas

As of yet, there are no full-scale operational anaerobic digesters for the centralized treatment of faecal sludge in developing countries. ...

and

...lack of existing implementations

As long you are maybe going just and "only" for a large scale centralized approach (plant) with all the problems of less resilience's and much more transport costs and typical traffic problems within big towns, I fully agree with you.

Maybe you look more in the direction towards South-South know-how and technology transfers and you will find existing "Municipal Sludge Treatment Plant" in "warm" countries (medium size full-scale operational anaerobic digesters for the [semi-]centralized treatment of faecal sludge in developing countries)

Repeating centralized problems through large scale plant solutions of "cold" countries within "warm" countries is not a solution!

Having several medium sized Sludge Treatment Plant's decentralized located would have more resilient for the users/towns and will reduce upcoming transport costs and typical traffic problems.

According to Indonesian colleagues STP's are proven and affordable biogas-solutions.

...STP costs around $100.000 USD depending on the load capacity and regional conditions. ...

Implementations are found in Aceh and Mojokerto Municipalities in Indonesia.

- Banda Aceh: "This facility is intended to provide the capacity to treat 60 m3 of sludge from Banda Aceh City per day, which is in addition to the existing facility with a capacity of 40m3/day. This capacity is sufficient to serve a population of approximately 250,000 inhabitants from Banda Aceh City and Aceh Besar Regency. The cost of the new sludge treatment plant is US$ 470,000, which will be financed by UNICEF. "

- Mojokerto City: "This plant has a designed capacity of 30 m3/day and designed to serve a population of 120,000. The project implementation cost is approximately US$ 150,000. The implementation is co-financed by BORDA, Ministry of Public Works, and Mojokerto Municipality. The engineering design was developed by the engineering team of BORDA, and LPTP, project construction will be administered and supervised by BEST."

2005: www.best.or.id/modules/news/article.php?storyid=23
2010 IWA: www.iwaponline.com/wpt/005/0095/0050095.pdf

What do you think about it?

Good luck in your undertakings

Detlef

see too

Hi Authors,

Excellent article! Can we apply this knowledge in real practice? One of our grantees is implementing a large scale FSM project in Khulna, Bangladesh (see: forum.susana.org/forum/categories/99-fae...thern-bangladesh-snv). Please advise how can you assist them.

Thanks.

Thank you Sebastian!

Dear All, please note the article is open access, so it can be downloaded and shared by everyone. Cheers, Linda

Dear Forum Users,

A new article in the Journal 'Resources, Conservation and Recycling' is looking at the economic value of faecal sludge in a sub-Saharan context. Some Co-authors are members of this Forum. Maybe questions and remarks could be interesting for all of us?

Find the article attached or in the following link:

www.sciencedirect.com/science/article/pii/S0921344914000913

A value proposition: Resource recovery from faecal sludge — Can it be the driver for improved sanitation?

Stefan Diener, Swaib Semiyaga, Charles B. Niwagaba, Ashley Murray Muspratt, Jean Birane Gning, Mbaye Mbéguéré, Joseph Effah Ennin, Christian Zurbrugg, Linda Strande

Abstract

There is currently a lack of access to affordable sanitation in urban areas of Sub-Saharan Africa. This study evaluated the potential for resource recovery from innovative faecal sludge treatment processes to generate a profit that could help sustain the sanitation service chain. A total of 242 interviews were conducted in Accra, Ghana; Dakar, Senegal; and Kampala, Uganda to compare markets in different cultural and regional contexts. Products identified to have potential market value include dry sludge as a fuel for combustion, biogas from anaerobic digestion, protein derived from sludge processing as animal feed, sludge as a component in building materials, and sludge as a soil conditioner. The market demand and potential revenue varied from city to city based on factors such as sludge characteristics, existing markets, local and regional industrial sectors, subsidies, and locally available materials. Use as a soil conditioner, which has been the most common end use of treated sludge, was not as profitable as other end uses. These findings should help policy and decision makers of sanitation service provision to design financially viable management systems based on resource recovery options.

© 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-NDlicense (creativecommons.org/licenses/by-nc-nd/3.0/).




[posted by Sebastian Klos]