In order to give you all a bit more information "to chew on" for this grant that we carried out at our university in Durban, please find attached the final report with all the results for Phase 1. This report was submitted to the Foundation in November 2012.

Please let me know if you have any questions. I would be happy to answer them.



Or see here in the SuSanA library (document number 16):
www.susana.org/lang-en/library/library?v...eitem&type=2&id=1707

Regards,
Chris

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Note by moderators: This post was made by a former user with the login name ChrisBuckley who is no longer a member of this discussion forum.

Dear Elisabeth,
Below please find a response from Chris Buckley to your questions posed in your post:

I understand your confusion. I will provide the long answer…

The Pollution Research Group (together with eThekwini Water and Sanitation) is involved in a number of projects funded by the Gates Foundation because Durban is a popular research site. The projects include:
• University of Maryland – Menstrual Management and Sanitation. Path and SEI are co-partners
• Eawag – VUNA: Nutrients from Urine

The PRG also has consultancies:
- Mechanical Properties of Faecal Sludges. This project is to produce data on sludges from traditional pit latrines, VIP latrines, UDDTs, pour-flush toilets, community ablution block toilets and School toilets.
- Economic Evaluation of Faecal Sludge Disposal Routes: This project aims to develop a versatile economic model to enable a total cost comparison between the processing of the contents of Ventilated Pit Latrines ("VIP'') in order to:
(i) Sell Latrine Dehydration and Pasteurisation ("LaDePa") agricultural pellets and
(ii)Sell/ produce ash from a total combustion process.

At the end of the RTTC Phase 1, initial tests had been carried out to characterise the input waste streams and the processing of segregated faecal and solid waste and urine streams. A prototype pedestal was designed and tested on a laboratory scale, but was not taken further. A proposal for Phase II is being processed. It expands on the provision of data on different sanitation streams, supporting other RTTC grantees in the field testing of their prototypes, facilitating field and laboratory studies by other Grantees in Durban and adjacent countries, providing laboratory access to work with excreta samples. In addition, generic processes such as pumping, extrusion, filtration, drying and pasteurisation on excreta samples will be undertake. Generic transformation models will be produced.

In response to your particular questions:

1. To what extent have you achieved the goal of the project?

The prototype pedestal was built and tested, but was not developed any further. A limited number of analyses and tests were carried out. These will continue under the second phase.

2. What has been the biggest frustrations to date?

- Lack of suitable project team members from the start of the project – recruitment of students and staff was only possible after the start which delayed the work
- Lack of awareness as the amount of time that would be required for setting up collection procedures which resulted in delays for the rest of the project
- External laboratories are unwilling to test these types of samples which placed an additional burden on undertaking physical and chemical analyses in-house; and the setting up of specialised equipment

3. What have been the biggest successes? (which of the 7 posters actually describes the most promising aspect of the research project?)

- Data gathering has been very valuable
- The pit scanner proved to be invaluable in undertaking pit-filling investigations
- The sludge extruder focused attention on the large amount of non-excreta material in a pit
- The recognition that source separation provides many processing advantages was useful to other grantees;

4. What have been enabling factors to make this project a success?

The active assistance from eThekwini Water and Sanitation has been crucial to the success of this work

5. When can your technology be brought to scale and under which conditions?

It will not be brought to scale

6. Where do you see its biggest niche or application area?

Our change in focus to data collection (and the rapid publication in open access journals such as Water SA will ensure that the missing data reaches a wide audience)

7. And what about the costs? What would the toilet or the ablution block cost in capital and in O&M if it was rolled out on a larger scale? (I know that the Gates Foundation had made exctremely low limits on allowable costs - was this achievable in the end?

We did not examine costs at this stage of the technology development

I trust that this answers your questions? Please let me know if you need further information.

Below please find links to two YouTube videos on the work carried out by:

• Konstantina Velkushanova on the Mechanical Properties of Faecal Sludge, and
• Ruth Cottingham on the Reinventing the toilet at UKZN and Properties of Faecal Sludge.

Both were presented at the Second International Conference on Faecal Sludge Management (FSM2) that took place in Durban, South Africa during 29 to 31 October 2012.

Dear Chris,

Thanks for making these interesting research results and concepts available. Those 7 posters that you shared are very well done and give an interesting overview.
(they can be accessed here in the SuSanA library:
www.susana.org/lang-en/library?view=ccbktypeitem&type=2&id=1707 )

I am a bit confused though. The goal of the project was very ambitious, given the very short time span of the project of just over a year! I suppose the time was just enough to develop concepts and carry out some initial tests, but now the funding has ended and what comes now? Is the further development currently on hold?

My other questions are:

1. To what extent have you achieved the goal of the project?
2. What has been the biggest frustrations to date?
3. What have been the biggest successes? (which of the 7 posters actually describes the most promising aspect of the research project?)
4. What have been enabling factors to make this project a success?
5. When can your technology be brought to scale and under which conditions?
6. Where do you see its biggest niche or application area?
7. And what about the costs? What would the toilet or the ablution block cost in capital and in O&M if it was rolled out on a larger scale? (I know that the Gates Foundation had made exctremely low limits on allowable costs - was this achievable in the end?

(reminder about the costs:

”maximum costs of $0.05 per person and day; this goal refers to total costs, including capital and operating costs.”

, see also here a previous post about this:
forum.susana.org/forum/categories/97-oth...g-capital-costs#2928)

I look forward to your responses. It is good to see that you have assembled such a big group of partners as well (see above the partner list in Chris' post). Hopefully they could also get engaged in this discussion.

Regards,
Elisabeth

Here comes the "formal" introduction of my research grant under the Reinvent the Toilet Challenge (RTTC) Round 1:

Title of grant: Data and design: mineralization of sanitation wastes from community ablution blocks

Subtitle (more descriptive title): Development of a three-way split pedestal with trash separation and extrusion of solid material

Name of lead organization: University of KwaZulu-Natal

Partner organisations:
Hering www.heringinternational.co.za
Envirosan www.envirosan.co.za
Partners in Development www.pid.co.za/
eThekwini Municipality www.Durban.gov.za
Water Research Commission www.wrc.org.za

Primary contact at lead organization: Chris Buckley

Grantee location: Durban, South Africa

Developing country where the research is being or will be tested: It is already being tested in South Africa.

Short description of the project:
The conceptual flowsheet was to produce three excreta containing streams (urine, washwater and a relatively dry solids). The scale would be a community ablution block serving 75 households (as is currently used in informal settlements in Durban). The solid stream would be separated into extrudeable pellets and detritus. The pellets would be dried and incinerated to ash. The urine stream would be filtered through a microfiltration membrane (under gravity) to remove colloidal material thereafter forward osmosis would be used to concentrate the saline components. The osmotic draw solution would be a recycled ammonium carbonate stream (urea decomposes to ammonia and carbon dioxide). The excess energy from the combustion of the faeces would be used to drive the Forward Osmosis system and to recover ammonia and carbon dioxide. The washwater would be separated by a membrane process. The concentrate would join the faecal stream and the filtrate would join the urine stream.

The project developed a three-way splitting pedestal in conjunction with Envirosan. An extrusion device was developed (based on the process used by eThekwini Water and sanitation in their LaDePa process) to separate faeces from non-faecal material. The viscosity of fresh faeces (with different moisture contents) was determined under a range of sheer rates, temperatures and pre-shearing conditions. A drying rig was constructed to determine the rate of drying of different geometry pellets and the conditions needed for pasteurisation of the pellets. This rig was not commissioned before the end of the project. No progress was made with the treatment of the washwater or the urine.

Goal(s): The goal of this project was to design, prototype, and evaluate a toilet system that can safely dispose of pollutants and recover valuable materials such as water and carbon dioxide from urine in community bathroom blocks.

Objectives:
The project was based on conditions pertaining to the conditions where the investigators are based. The objective of the project was to process the excreta from a community ablution block in an informal settlement, which would serve 75 households with an average of 5 people per dwell. (About 1 000 000 people live in informal settlements in Durban and are in the process of being served with community ablution blocks.) Further, the project builds on the experiences and developments of our project partners who are all involved in addressing the needs of poor unserved communities.

Start and end date: 20 June 2011 to September 30, 2012

Funding for this research currently ongoing? An application is in the pipeline for Phase II funding

Research or implementation partners: Partners in Development, Envirosan, Hering, eThekwini Water and Sanitation, Water Research Commission

Contacts, links, further readings: Factsheets, 7 posters and one powerpoint presentation are available here in the SuSanA library:
www.susana.org/lang-en/library?view=ccbktypeitem&type=2&id=1707

Please note that some scientific papers are currently in the making (they will be published in Water SA), so they cannot be shared yet. MSc theses are also not yet completed.

1-minute video about the concept (produced just after the Reinvent the Toilet Fair in Seattle, August 2012):


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Note by moderators: This post was made by a former user with the login name ChrisBuckley who is no longer a member of this discussion forum.

Greetings,

I have added the draft of a paper submitted to Water SA entitled Modelling the filling rate of pit latrines to the ‘Resources’ tab [of the former Sanitation Network]. It is based on data obtained from pits in Durban, South Africa.

Excreta (faeces and urine) that is deposited into a pit latrine are subject to biodegradation,
which substantially reduces the volume that remains. On the other hand, other matter that
is not biodegradable usually finds its way into pit latrines. The net filling rate is thus
dependent on both the rate of addition of material and its composition. A simple material
balance model is presented which represents the faecal sludge as mixture of biodegradable
organic material, un-biodegradable organic material and inorganic material. Measurements
made on two pits in eThekwini, South Africa were used to determine parameters for the
model. Model predictions were then compared with data from 15 other pits in the same
area and filling rate data from previous South African studies. These comparisons
indicated that the pits studied exhibited relatively low filling rates resulting from orderly
disposal practices. The average composition of the pit (COD, biodegradable material and
inorganic fraction) changes with age, which will impact on any subsequent sludge
treatment process. Pit filling rates are greatly affected by the disposal of solid waste in
addition to the faecal material. For the pits studied, the model predicts that the filling time
could have been extended from 15 y to over 25 y if all solid waste had been excluded from
the pit.

Keywords: Pit latrine, filling rate, biodegradation, solid waste disposal

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Note by moderators: This post was made by a former user with the login name ChrisBuckley who is no longer a member of this discussion forum.

Greetings,

I have added the results on an on-going study into the nature and composition of the contents of VIP latrines in Durban, South Africa to the Resources page [of the former Sanitation Network]. This work was carried out by Tunde Bakare a PhD student with the Pollution Research Group.

This study investigated variations in the characteristics of the sludge content from different ventilated improved pit (VIP) latrines and variation in these characteristics at specific depths within each pit. Faecal sludge from 16 VIP latrines within the eThekwini Municipality was collected and laboratory characterisation including moisture content, total and volatile solids, chemical oxygen demand, and aerobic biodegradability was performed. Sludge samples were collected from 4 specific depths within each pit investigated. The laboratory characterisation performed showed that none of the VIP latrines investigated had the same sludge characteristics, and that within a pit sludge characteristics varied with increasing depth in the pit. This supports the motivating hypothesis that, depending on household habits and local environmental conditions, there should be considerable variation in the organic contents, moisture content, non-biodegradable content and microbial population between different pits. This variation with increasing depth within a pit is expected, since fresh material is constantly being added to the pit overlaying older material which might have undergone a certain degree of stabilisation.

Keywords: stabilisation, household habits, aerobic biodegradability, sustainable

dx.doi.org/10.4314/wsa.v38i4.2

Available on website www.wrc.org.za
ISSN 0378-4738 (Print) = Water SA Vol. 38 No. 4 July 2012
ISSN 1816-7950 (On-line) = Water SA Vol. 38 No. 4 July 2012 479

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Note by moderators: This post was made by a former user with the login name ChrisBuckley who is no longer a member of this discussion forum.