SuSanA - Forum Kunena Site Syndication Thu, 28 May 2015 15:46:54 +0000 Kunena 1.6 SuSanA - Forum en-gb Re: Who is doing toilet and FSM product and technology design / R&D and what are you working on? - by: dandreatta
Again, sorry for the slow response, my regular job and some other volunteer work has kept me busy lately.

Thank you for the complements. Sometimes having a limited budget saves time by forcing one to work efficiently. Since Christoph has made the most comments, I'll respond mostly to his comments.

First, the 3 videos I presented are 3 separate ideas, they can be used together or separately. The pasteurization ideas (not shown in videos) are other separate ideas.

The pit emptying device has been developed further since the video was made. It certainly does need to be improved in durability and some other things, at this point I'm working on the basic idea to make it functional. There will be videos of better versions coming soon. The newest version is much more compact. To dump the bucket requires only gravity, as about 2/3 of the bucket is beyond the pivots. Pulling on the rope pivots the bucket up, and releasing the rope allows gravity to pivot the bucket down. It seems to work well for both very liquid sludge and more solid sludge. One thing I will do soon is find out how solid the sludge can be, as I have gotten feedback that sometimes the sludge is very solid, almostly like dirt.

Regarding the tipping basin, it was lined with a teflon sheet, and in the week that I used the device as my toilet most things did not stick to the teflon very much. I don't know of any less sticky surfaces. Maybe a surface that is very water repellent? Various levers and ropes could be used for manual dumping with no water, with the disadvantage that your hand or foot would be touching what someone else's dirty hand or foot has touched. Perhaps that is not such a big deal, since each user is touching the same door that others have touched.

Regarding the solar pasteurization, I also see some gaps in that design, mostly related to its performance. Of course, here at 40 degree North latitude we don't have tropical sun, and the performance was pretty marginal here in the northern summer. I did not include any UV effects, as I assume that the UV does not penetrate very far into the feces. According to Feachem and many others, the most heat resistant pathogens are enteric viruses, so the helminth eggs should be well cooked at these temperatures. The green line (showing log reduction of pathogens) was calculated from the measured temperature at the (assumed) coolest spot in the feces. The relationship between time, temperature, and die off was based on enteric viruses and based on data given in the famous work from 1983 by Feachem and others. The mathematics for relating time and temperature to die off are fairly simple, though I'll leave the details for another time.

For reference, I have attached the newest version of the document that talks about all these ideas, including the time-temperature-die off curves from the pasteurization tests. The 3 youtube videos are referenced in this document, as well as my recent tests with the dumping basin.


Faecal sludge transport Wed, 13 May 2015 01:30:32 +0000
Re: Who is doing toilet and FSM product and technology design / R&D and what are you working on? - by: christoph I do think you are on the wrong track! It is not possible as you are suggesting. And You misunderstood (maybe ) my obersvation.
a) 1,1 m³ is a lot if you have to get it out without access of a tanker
b) how do you solid separation?
c) how do you treat the liquid? Just to leave no doubt - I did not suggest to treat it with uv! And UV treatment for sure is not enough. you need a secondary biological treatment (as for every liquid which goes out of a solid separation.
solid that is left over will, if properly aerated, degrade to mineral

How do you do that? That would be the solution for our problems!


Note by moderator: The answer by Vishwanath has been moved into this new thread:]]>
Faecal sludge transport Sun, 10 May 2015 13:51:33 +0000
Re: Who is doing toilet and FSM product and technology design / R&D and what are you working on? - by: vishwanathdalvi Where does that go?"

I am glad you did the calculation for me The numbers line up with what I had imagined.

1.1 m3 is not a large volume (its a small water tank occupying about 10 square feet of floor space). Further, a lot of this is liquid, which can be drained and (as you suggested) sterilized with a UV Led.
The solid that is left over will, if properly aerated, degrade to mineral. So that 1.1 m3 can last decades without clearing.

I would love to hear your views on this.

With kind regards,

Faecal sludge transport Sun, 10 May 2015 13:04:59 +0000
Re: Who is doing toilet and FSM product and technology design / R&D and what are you working on? - by: christoph just now I came to read you material and to take a look at the videos. Congrats very interesting ideas. I would like to comment on some aspects. (I think your proposal should have a more prominent space as it is interesting - the titel of the thread is right, but not pointing to a really ineteresting solution)

a) the bucket (first video) really is a very interesting solution as a simple device for emptying dry pits... I think there might be some issues with the durability of the material, but that is all possible to solve I guess even with cheap material.

b) I don´t see the bucket as a good solution as demonstrated for liquid emptying, I guess it would be better to have a stick instead of the rope, by that you can tip the bucket and fill it more rapidly.

c) the tipping device is definitely a very interesting idea for pits in my understanding, I was impressed. I have seen it so often for measuring of volume but it never occurred to me for this application. For sure it is easy to close better the gaps between pit and bowl with a rubber seal (obviously that might be influencing the tipping weight). The bowl must be some sort of very anti sticking material (teflon like?), if not that might be a problem. But even with some “rests” better than an open hole . Attaching a thin rope at the back of the bowl going out below the seat at the back, would not be a solution to tip it without water? (yes a dirty hand could have pushed that rope… but the same hand might have opened the door as well…)

d) for the solar pasteurization device I do have some doubts. First of all I really appreciate the effort you put into that and the results you gained with so little resources. There are some BMG projects with more resources and less results out there. I think the temperature measurements are very interesting… BUT the collusion you are drawing .. I understand based on your trials with water solarization (please correct me if I am wrong) are dubious to me… will say. ..

1) the green curve was not measured, it was plotted due to your experience with water.. right?

2) Did you consider that UV has a strong influence as well for die off of coliforms in the case of water?

3) you speak of pathogens, I think you refer to coliforms? Not helminth eggs.

But again, congrats for the achievements they are food for thought.

To vishwanathdalvi. Do a calculation. 5 persons, 365 days 0,5l /water,use, 0,12 l/ feces,d,pe. = 1,1 m³/year
Where does that go?

Faecal sludge transport Sun, 10 May 2015 12:44:36 +0000
Re: Who is doing toilet and FSM product and technology design / R&D and what are you working on? - by: vishwanathdalvi Faecal sludge transport Sat, 09 May 2015 17:09:04 +0000 Re: Who is doing toilet and FSM product and technology design / R&D and what are you working on? - by: dandreatta
The basic results are that the system worked as designed, though a few improvements are needed. The average water usage was 486 grams. Everything flushed (dumped) properly with no splashing or splattering. The odor was mostly contained within the vessel, though reduced gaps around the edges of the basin would have contained the odor better.

Regarding your question about whether the system could be made smaller so as to use less water, the basin could be made a little smaller, but not much. The basin was pretty full at times.

The attached report covers 4 sanitation solutions, the mechanical dumping toilet that is the subject of this discussion is the second solution and starts somewhere around page 5.


Dale Andreatta
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Faecal sludge transport Fri, 08 May 2015 22:22:17 +0000
Re: Ubuntu-SAN: Point-of-use dry sanitation and sludge beneficiation micro-entrepreneurship model (mobile, decentralised sludge sanitiser via solar pyrolysis) - by: joeturner

The interesting thing about it is that the insulation around the stove pipe ensures that the fuel inside burns very fast and very hot.

My question is this: as I understand the description above, the solar system chars the faeces to use as fuel in the stove. The video seems to have wood burning in the stovepipe, is the suggestion that the charcoal would go inside the insulation chamber? I have heard of wood being charred efficiently in this way, I am wondering whether this is the intention here.

I have contemplated sanitation systems where faeces is collected inside a chamber, which is then converted into a rocket stove which then chars and sanitises it. This might well produce noxious fumes, so your solar charring method may well be safer..]]>
Faecal sludge transport Thu, 07 May 2015 19:47:21 +0000
Re: Ubuntu-SAN: Point-of-use dry sanitation and sludge beneficiation micro-entrepreneurship model - by: muench Wade Edwards (who posted just above me) made a presentation about his project in Hanoi, see here:

UbuntuSAN: A micro-entrepreneurship model for point-of-use dry sanitation and sludge beneficiation using concentrated solar power: Wade Edwards, Atl-Hydro, Department of Chemical Engineering, Cape Peninsula University of Technology, Cape Town, South Africa

Video (the sound is a little low at first but gets better after a minute):

Or see here, where his part starts at 18:18

There are some really nice pictures in his presentation, well worth a look. He also talks about cartridge based solutions (see also here on the forum:

Faecal sludge transport Wed, 06 May 2015 11:22:23 +0000
Re: Who is doing toilet and FSM product and technology design / R&D and what are you working on? - by: vishwanathdalvi Faecal sludge transport Sun, 03 May 2015 14:06:27 +0000 Experiments regarding pit emptying devices and clog-proof toilet (mechanical toilet that uses little water) - Ohio, USA - by: dandreatta This thread used to be here ("Who is doing toilet and FSM product and technology design?"):

I'll add my 2 cents worth here. I am doing toilet and FSM technology design. I am an independent engineer working on sanitation in my spare time.

I've developed some prototypes of a pit emptying device, see

This is not a universal solution, of course, but should work well in some places, and is certainly better then the poor men climbing down into the pit.

I've also developed a low water clog-proof toilet, see

I've used this for a while and it works well, though it needs some changes.

I'm also working on an above-ground latrine made of a barrel for high water tables, which can be emptied using something like the mechanism shown in

This one is still in the early stages of development, so I can't claim too much yet.

Dale Andreatta, Ph.D, P.E.]]>
Faecal sludge transport Sat, 25 Apr 2015 21:20:16 +0000
Re: Training sessions with pit emptiers in Mombasa, Kenya, using the Gulper: training materials we might use in our trainings? - and incentives - by: rsklar
Thank you for your questions. Incentive schemes were designed to encourage sludge disposal at future site of the waste-to-fuel plant as opposed to hapazardly in the community. Emptiers in the treatment group received the opportunity to take advantage of two incentive programs: 1) sludge pick-up from a focal point in the community or 2) sludge drop-off dropping at the plant in exchange for a cash reward on a per volume basis. All transportation costs were paid for by Pivot during the trial period. All emptiers in the treatment cohorts were entitled to use equipment provided by pivot such as 50 gallon barrels and PPE (rubber boots, rubber gloves, protective eyewear, respirators, coveralls, and rubber jumpsuits) and stored in "sanistations" in the community. Incentive one, sludge pick-up from a focal point, was chosen in 21 of 22 empties that took place over the course of the trial. It was more feasible for the emptiers as most didn't have access to a vehicle to use for drop-offs.

Hope that answers your questions. I am very happy to share my photographs with the SusanA community on the flickr database. I am happy to provide the images in their original resolution.

Faecal sludge transport Wed, 22 Apr 2015 20:03:24 +0000
Re: Training sessions with pit emptiers in Mombasa, Kenya, using the Gulper: training materials we might use in our trainings? - and incentives - by: muench
Thanks for posting your presentation. It's a pity the video of your presentation is not yet available but I have heard that they are coming soon now (sneak preview:

Just based on the powerpoint slides, I couldn't quite understand which incentives exactly you offered? And which incentives worked the best? Was it mainly just about providing personal protective equipment (but how would that be an incentive to deliver the fecal sludge at the designated collection point?)?

I found it interesting that you listed these three costs of the pit emptiers:
  1. Alcohol (to make the work bearable!)
  2. Bribes (to bribe local leaders!)
  3. Chemicals (to "disinfect" the sludge - which chemicals do they use? Is this something you'd discourage in future as it could interfere with reuse options if you have nasty chemicals in the fecal sludge?)

And finally, I would like to ask you about your pit emptying photos. Would you be willing to make them available in the SuSanA flickr database? We are always after good photos showing the grim realities of dealing with fecal sludge...
You see other photos from Kenya, which Doreen Mbalo had provided in the past, here:

Faecal sludge transport Tue, 14 Apr 2015 10:06:46 +0000
Re: Comparison field tests: Equipment for emptying and transporting difficult pit latrine sludge in Blantyre, Malawi - WASTE - by: hajo
I also had the idea to fludise pit sludge with a high pressure water sprayer (KAERCHER) to make it pumpable and I am delighted to see somebody has turned the idea into action and tested it.

My next step would be to see whether I can filter the spray/pump water on site, 'recycle' and re-use it in order to reduce the quantitiy of water I have to transport to and from site. In large the technique exists in MUELLER sludge tankers (see )which will be too big to suit to your equipment.

But there may be a nano-filter technique which may provide a similar service. Is there somebody on the forum who can provide more insight into the possible application of such technique? I know the BLUE DIVERSION of EAWAG is also using filter membranes for water treatment. We are not looking at production of drinking water but only bringing the water to a condition where it can be re-used for spraying without blocking the nozzles.

Another advantage of the on-site filtration would be the de-watering of the sludge to a condition where it can be fed into a LADEPA plant, which requires 30-35% solid content (limits still to be confirmed with EWS in eThekwini).

The Fecal Sludge Omni-Ingestor (FSOI) suite of technologies for fecal sludge emptying and transport (contract by BMGF, see seems to go into the direction of de-watering the sludge as well. Maybe we can learn something from them further developing your system.

I am keen to find a professional and more effective way to empty pits beyound using shovel and gulper. With thousands of pits in every African town it can still provide decent work for people and hopefully a sustainable service chain to customers.

ciao, Hajo]]>
Faecal sludge transport Mon, 30 Mar 2015 13:51:08 +0000
Comparison field tests: Equipment for emptying and transporting difficult pit latrine sludge in Blantyre, Malawi - WASTE - by: WASTE
The equipment tested was: Vacutug, Diaphragm Pump and the ROM. In the lead of this operation, Joseph DeGabriele presented his findings during the FSM3 conference in Hanoi this year.

The ROM came the best and together with WASTE developed a Mobile Desluging Unit, optimised for difficult pit's, which is already in production.

For the presentation see:

For a short movie about the Mobile Desludging Unit of ROM: ]]>
Faecal sludge transport Fri, 27 Mar 2015 07:29:09 +0000
Re: The excrevator (power auger) to empty pits (North Carolina State University, USA) - now field testing - by: muench
For those of you following progress of the excrevator tool by the group of Francis at North Carolina State University, take a look at this presentation at the FMS3 conference:

The “Excrevator” - Safe and Effective Pit Emptying: Tate Rogers, North Carolina State University, Raleigh, NC, USA

It includes results from their field testing in:
  • Hyderabad, India
  • Durban, South Africa
  • Mzuzu, Malawi

From their summary slide:
  • The Excrevator is an effective pit emptying tool if trash content can be managed
  • An assortment of tools are necessary to empty the high variability of existing pits
  • Field testing to continue in Malawi in Early 2015
  • New field testing locations to be determined

As far as I know, their current phase of funding is coming (or has come) to an end, so I think they are looking for more funds for further R&D, so I wish them good luck with that!

Faecal sludge transport Tue, 17 Mar 2015 09:39:15 +0000