You may find the following link interesting. It’s author is Dr. Olivier, the BioPod inventor.

http://www.esrint.com/pages/bioconversion.html

At very end of the page you will see a reference to urine diverting toilets. Dr. Olivier has worked with the governments of a few countries on programs that address the processing of human waste. I believe his position is that these developing countries don’t need to invest in an expensive sewer system like ours which mixes potable water with feces and urine. Instead a family could operate a BSF bio-conversion unit that would handle all putrescent waste and produce valuable larvae as a byproduct.

From what I’ve read the liquefaction is largely caused by the presence of urine. At a blog called pond boss (I presume you’ve seen it) the person writing the thread on BSFL described his experiments feeding BSFL, including dry hog feed. While others have written in mentioning all the “worm tea” the BSFL produce, it’s clear that that is largely a factor of the water content of the food. The BSFL fed dry hog feed didn’t produce “tea”. Feces separated from urine, or a system which allows the liquids to drain out could provide a drier medium that wouldn’t lead to um turd soup.

Ideally, a BSF process for dealing with human excrement in the developing world would be more contained than the floor of a livestock pen. Unlike livestock, we try not to walk around in our own excrement. And we can control the moisture by adding fluffing material or removing the moisture.

I’ve not been able to locate any information on the use of BSFL in human excrement processing, but if a system could be developed and introduced to developing countries where sanitary standards are abysmal, this could be a good way to cut the volume of and problems associated with human waste. Admittedly, my comment is speculative, so if anyone has actual information, I’d be interested in seeing that.

It’s a common observation that BSF larvae liquefy manure as they process it, but if properly managed the benefits seem to outweigh the obstacles. The most significant point is that BSF limit the presence of disease carrying houseflies, and there are ways around the problem of liquefaction, at least on a commercial scale. Designs have been tested at both poultry and swine operations using BSF larvae to reduce manure with good results. I think the urine is separated from the manure to reduce liquefaction. There’s also the side benefit of harvesting the mature larvae and feeding them to the animals that created the manure. Here’s a link that I believe address some of these issues:

http://www.cals.ncsu.edu/waste_mgt/smithfield_projects/phase2report05/cd,web%20files/A2.pdf

It does mention that the presence of BSF larvae seems to help reduce the numbers of ‘house fly’ larvae. But it also mentions something about the ‘manure’ being liquefied, except it doesn’t put it in such a positive light as Michael May put in his comment (and the comment made on the NYtimes blog site) since it says that it makes it ‘difficult to remove’ and ‘may block up walkways (in the poultry house”.

Any thoughts?

Thank you!

Widespread adoption of BSFL as a means of dealing with human excrement in the developing world could conceivably save millions of lives per year. It could eliminate the flies and open sewers that spread disease largely to children. And it would provide an important source of protein for feeding chickens to improve the production of eggs and meat for human consumption.

This needn’t even require someone to collect the larvae as they could simply be dropped in a place where the chickens could self-feed.

And a well-designed unit could redirect urine which could be an important source of nitrogen in countries with poor soils.