Solar treatment for Faecal Sludge treatment

  • Kad90
  • Kad90's Avatar
    Topic Author
  • Posts: 2
  • Likes received: 0

Solar distillation for Faecal Sludge treatment

Hi all,

I am an entrepreneur exploring the area of sanitation and have been studying various designs for faecal sludge treatment. In many developing countries where desludging and maintenance of wet sludge (in any form - treated or not treated) is one of biggest challenges, treatment of faecal sludge where the end result is a dry solid waste seems quite promising. I have read about photo dryer, solar thermal heating etc. Want to know from the experts in this forum about the feasibility and effectiveness of this technology. Why has solar treatment of blackwater and faecal sludge nt taken off as much as other technologies?

Thanks in advance.

You need to login to reply
  • JKMakowka
  • JKMakowka's Avatar
  • Just call me Kris :)
  • Posts: 955
  • Karma: 35
  • Likes received: 309

Re: Solar distillation for Faecal Sludge treatment

What makes you think it "hasn't taken off"?

Given the specific circumstance that there isn't in general much sludge treatment taking place in most countries with sufficient solar radiation to make it viable year round...

So aside from export driven and loan funded transplanted sewerage treatment facilities that follow northern European technology standards, sludge drying beds are quite popular, I think.

In technical terms the main issue is seasonal variability in term of cloud cover and especially air humidity, which has a huge impact on the quanity of sludge that can be processed. Thus to allow sufficient treatment capacity all year around a lot of space is needed, which is usually not available within realistic transport distance.

In addition to that, unless only fed with stabilized sludge or pretreated somehow, it can be a significant smell nuisance, which again very much limits the places it can be implemented within a realistic transport distance.

Microbiologist & emergency WASH specialist
WASH news aggregator at:
The following user(s) like this post: samshancn
You need to login to reply
  • Kad90
  • Kad90's Avatar
    Topic Author
  • Posts: 2
  • Likes received: 0

Re: Solar treatment for Faecal Sludge treatment

Thanks for the reply, Kris.

What I meant by not taking off is that most of the treatment plants are funded or pilot projects with sustainability and the validity of the project yet to be validated.

And, yes I am aware of the solar drying bed, but even that involves transporting the sludge to these treatment centres where they can be dried under the sun and converted into utilizable fuel.

Just to be clear, I am thinking of a decentralised, in-situ technology that could cater to say 10-15 toilets (community toilets ) or individual households (if possible), where the waste can be treated on-site using a small scale photo dryer (and the like) and the wastewater can recycled.
You need to login to reply
  • muench
  • muench's Avatar
  • Moderator of this Forum; Freelance consultant and Wikipedian (former roles: program manager, lecturer, process engineer for wastewater treatment plants)
  • Posts: 2664
  • Karma: 52
  • Likes received: 729

Re: Solar treatment for Faecal Sludge treatment

Hi Kad,

Funny that you brought up this topic now: I was just e-mailing with Santiago Septien from South Africa (Uni KwaZulu Natal) last week about the issue of solar sludge drying. I asked him if he'd like to post about it after seeing his presentation at the FSM5 conference online:
His presentation was called solar drying of faecal sludge so I think you'll find it useful.

Two previous discussion threads on this forum could be interesting for you as well:

Solar treatment of feces? - to treat feces with solar energy in order to kill the pathogens in the feces quickly

Research project about faecal sludge drying, at the Pollution Research Group (South Africa)

There have been other discussions about solar treatment on this forum which you can find by putting "solar" into the search field.

Anyway, just thought I'd give you this background for your literature search. Let us know how you get on with this.


Community manager and chief moderator of this forum
(Funded via GIZ short term consultancy contract)

Dr. Elisabeth von Muench
Independent consultant located in Brisbane, Australia
This email address is being protected from spambots. You need JavaScript enabled to view it. Twitter: @EvMuench
Sanitation Wikipedia project leader:
My Wikipedia user profile:
You need to login to reply
Share this thread:
Recently active users. Who else has been active?
Time to create page: 0.811 seconds