There is an entirely different approach that could be taken. Thoughtfully and practically design (indoor) toilets where the fecal waste is pushed(instead of flushed) out into a BSF composting unit. This would be a huge win, because then the cost of treating the waste water is substantially decreased.  Urine separating toilets would be required as well.  By composting the waste at the source where it is generated, you would realize several wins:  1. Lower cost to treat waste water   2. Lower cost to dispose of removed solids  3. You would encourage more people to also compost ALL of their food waste at home, reducing what goes into landfills, while reducing costs associated with collecting and transporting household waste.  If folks utilized used tires to build varmint proof BSF composting system, keeping tires out of landfills, and all of our food waste out of landfills would be more huge wins.         
There would be some minor logistical challenges, all of which could be easily overcome with a little ingenuity.

I see it's three years since anyone posted on this thread.

I am curious whether anyone, anywhere, has successfully managed to use Black Soldier Fly for processing faecal sludge.  By "successfully" I mean that the processing plant benefits exceeded costs (all costs, not just operating costs).

I was part of a team that designed, constructed and operated a nominally 20 t/d pilot BSF plant in South Africa from 2015 to 2019.  We were working with a company which was at the time regarded as a world leader in BSF technology, although their experience was limited to using BSF on food waste, not faecal sludge [despite this company's initial promise, it subsequently failed - seehttps://www.luxresearchinc.com/blog/what-happened-to-agriprotein/ . 

At the time we started the promise of technology was very exciting.  The pilot was, however, not successful.  Problems encountered were:

i) The larvae did not reduce the FS mass and volume significantly.  We concluded that a very large area (impractical in a city where suitable and available land is hard to find) would be needed in order to spread the sludge in a very thin layer.
ii)  FS from on-site toilets does not have a lot left in it for the larvae to feed on.  The FS has already been fed on by all kinds of biota for years and so much of food potential is gone.  This means that the FS must be supplemented with other nutrient sources, e.g. fresh faecal waste or food waste.  That adds costs, and if the FS itself is not much reduced by the larvae then you don't have an FS treatment system.
iii)     Separating mature larvae from the FS waste is not a simple or inexpensive process
iv)   FS larvae are temperature sensitive.  If you are farming BSF on the equator perhaps its more practical, but we concluded that we would need to spend a lot on climate control to boost productivity.
v)  Incubation of BSF eggs and hatching of larvae is not simple.  

I am therefore sceptical on the promise of BSF, at least as far as faecal sludge treatment is concerned.  If anyone has reports and data to prove me wrong, please share.  I do know that Sanergy has built a big BSF plant in Kenya, but I'm not sure what mix of feedstock it uses, and how the economics are working out.

Regards

Dave

Dear Heiner,
Thanks for your feedback and contributions. It is obvious that there are things that still need to be done to ensure that we ultimately harness the most of the potential created by the black soldier flies and their larvaes.
On the particular statement that you question (an excerpt of a communication note, not directly in the report), it is important to note that the statement refers to the area of land used to produce different protein sources, and not so much to the method of production of these proteins.

In the report, we have presented what the footprint of existing BSF plants, which could be typically 40m2 per tonne daily input of waste. The yield of larvae is often reported to be up to 118 kg dry weight per tonne of waste processed, with a protein content of 35 to 44% dry weight. It becomes possible to calculate the yield of proteins and compare it to what is seen in other sectors (e.g. one chicken needs 0.2 to 1m2 and will grow about ~3-4 kg (wet weight) in 3 months). By doing so, one notes that the land productivity with BSF is way higher (i.e. can attain 100 times the one for poultry), and this is the message we were trying to convey in simple terms that non-technical people would understand after reading the communication brief. But the report itself remains technical and addressed to a technical audience.

Best,
Josiane.

Dear Mohammad,
Thanks for your post, highlighting this new report (please always indicate if text is your own or if it's taken from another website; I have now changed your post so that it's clear that the text is not yours but copied from that website).

Heiner:
Thanks for your insightful commennts. I will contact the authors of the report to get a clarification on this misleading statement (I couldn't find the statement in the report but only on their website; I guess it was meant as an "attention seeker"... but it should still be correct. Thanks for pointing that out.

Saroj:
The report doesn't include examples in India. I used our SuSanA resources to see if I can help you: I checked in the SuSanA library for keyword "BSF" and found only these 7 entries: www.susana.org/en/knowledge-hub/resource...title=&author=&year=
We also have this sub-category on BSF here on the forum: forum.susana.org/147-production-of-insec...eta-or-organic-waste
In there I found a guide from EAWAG (www.eawag.ch/fileadmin/Domain1/Abteilung...te_Processing_LR.pdf) but again nothing about India.

Then I had a look at the SuSanA project database, filtering for BSF as a "reuse product" and found these 8 projects:
www.susana.org/en/knowledge-hub/projects...1%5B663%5D=663&test=

There was a project funded by the Gates Foundation in India which made a sub-grant on BSF research:
www.susana.org/en/knowledge-hub/projects/database/details/204

See here: forum.susana.org/forum/categories/147-pr...man-feces-research-p
It was at Indian Institute of Technology Roorkee.

Perhaps you could follow up with them. Their last post was from 2015:

As requested by Elisabeth, here is an update. There is nothing exciting to share with at this moment! We had an unusually long cold winter. The fund was released in January 2015. We are still working on to get used to the rearing of the fly and its larvae so that we can build a community of flies from where we get a continuous supply of eggs and larvae for further experiment. Once we get a continuous supply of young larvae, and other equipment are in place to conduct a scientific work, we will start working with human feces. Right now the larvae are being fed with food waste. We hope to let you know something exciting by August 2015.

forum.susana.org/forum/categories/147-pr...ces-research-p#13700

Hope this helps,
Elisabeth

Hello ,

I am also working on organic waste processing and presently trying out composting using different microbial cultures, however recently came across , Black Soldier Fly, just curious to know how feasible is this for large quantity of waste.like 10 tons per day.. and where i can see this in India,

Thanks
saroj

Dear Mohammad,
thanks very much for your input. I used soldier flies larvae as fish feed already (Tilapia) and think it is important to do some more research on it. F.e. the protein content of 20% is to low for young fish so they are more suitable for mature fish.

But the statement: "...can produce about 100 times more protein per year than chicken or soybeans, not to mention cattle, on the same area of land..." is simply wrong. Soldier flies can't produce a gram of protein if there is no organic material (waste). And all organic material is produced by plants (or algae). The flies can substitute chicken, pigs, cows and even fish... but definitely not plants like soybeans (legume).

To feed the world we have to intensify and optimise plant production....AND close the loop behind in a very efficient way. And here is a lot to do for the flies!

Have a nice day,
Heiner

From this website:
www.iwmi.cgiar.org/2019/11/global-experi...hnology-to-business/

Black soldier fly colonies can produce about 100 times more protein per year than chicken or soybeans, not to mention cattle, on the same area of land. The flies can directly feed on different types of organic wastes, leapfrogging closed loop processes within a circular food economy. Also, where no protein is needed, for example, to feed fish or pigs, the larvae can be processed into high-quality biodiesel. However, can this be done at scale? The answer is ‘Yes’. The report showcases some of the leading global businesses in Black Soldier Fly production.

www.iwmi.cgiar.org/Publications/wle/rrr/..._reuse-series_16.pdf