Quote:
Originally Posted by DoubleO7
True, however it supposedly is not human waste.
"When all the nutrients have been consumed, the microbes die. Agents are then added to begin clumping the microbes together. This process of settling and coagulating takes place in quiet sedimentation tanks.
After settling, the clumped microbes are removed and sent to the Dewatering and Drying building where moisture is removed using belt presses. This produces a semi-solid form similar to wet cardboard that is subsequently dried in twelve rotary driers at temperatures ranging from 900⁰ - 1200⁰F. Any surviving pathogens are killed from the extreme hot temperatures."
Being dried at At 900F+, I can't imagine there is any nutritional value to plants. It is more like sterilized dirt to me, but plants do seem to like it.
http://www.milorganite.com/Using-Milorganite/What-is-It |
This process is right up my alley of work, although I don't work with human municipal waste, I work with industrial such as pulp and paper mills etc, they utilize the exact same processes and biology. The clumping agents they refer to are polymers, specifically epipolyamines and polyacrylamides of which in the last 23 years of working as a chemist, I have developed a few.
They are nitrogen bearing chemistries which do have a nutrieve value and there are a few papers written where they have shown soil conditioning properties.
As far as the drying of the microbes with the polymers present after they have eaten the sewage, these microbes have consumed all the nutrients in the water such as all the organics, nitrogen and phosphorus in a specific ratio of 100:5:1 of BOD:N:P. Oven drying does not affect the nutrient nitrogen or phosphorus. It's still there after drying and is quite a good plant fertilizer source.
So, go ahead and use it. The drying kills all the life forms including pathogens and viruses but the nutrients such as nitrogen and phosphorus cannot be destroyed since they are elemental.