This is a story about pee & poo.

Fedde worked a lot in Asia in sanitation projects. He wanted to use his knowledge in a Dutch context, so he decided to create composting toilets for festivals.

It was easy to collect the human poo & pee, but how to treat it afterwards.

Because of the high temperature and the long retention times the biomeiler seems like an ideal solution for treating humanure.

Urine is not really a danger, it can be readily used in agriculture.

Feces is difficult, it can be treated by:

• drying
• composting
• fermenting
• burning

The first biomeiler project was not very successful in terms of heating, but this story is mainly about the sanitation aspect. The biomeiler was build with an outside of straw bales and the inside was completely wood chips except for the pee and poo (with sawdust). We made an underground tank to store the urine and waste water from washing.

Some parameters have been analysed.

E-coli is the main indicator for pathogens and it was completely taken out.

Some other, not dangerous, bacteria were still there after half a year, indicating some anaerobic conditions.

After a year all levels were very low and within safety limits.

In the second analysis also the fungi Aspigillus has been found. This can be treated with worm composting afterwards, this is now being done.

For medicine residues all 97 kinds tested were lower than 0,5 ppm. If this is safe is debated, but it’s a lot better than normal waste water treatment.

Literature shows that one of the most difficult substances (carbamazepine) to treat in waste water can be reduced by 88% in composting, which is a big change for this industry.

The value comparison is very hard, especially since it is not yet legal to sell this kind of compost. With a small biomeiler the return of investment is about 10 year or more, but with bigger systems it can be within 5 years. Using the compost or selling it can be done within the law in NL if you make an association where only the members are using it for themselves.

Another project has been build in Frylan near Leeuwarden.

This is a 100m3 biomeiler, also meant for waste water treatment. It has just been build, so there is no data about it yet.