[Start of Page 2 of the discussion thread]


After constructing six UDT for St. Monica girls secondary school we went there for a revisit and realized that most of the stool chambers are full. They are using the second chambers. This means that very soon they will be also full. The headmistress asked us who will be responsible for emptying them.

We concluded that though we trained them on O&M and she knows how to empty she is not ready for harvesting the manure. I have realised that there is a need to solve this gap economical. Therefore kindly assist me answer the following and I will make money out of this need.

1. What do you need for preparation of decomposed stool before emptying the vaults
2. What do you need when you want to add value to the decomposed stool
3. What is the mineral distribution in decomposed stool
4. What do you need to add value to harvested urine
5. What is the mineral distribution in the diluted urine (1 urine:3 water)
6. How does one arrive at the market value of the added value of both human waste respectively.

My regards

I can answer the last 3 of your questions.

4. What do you need to add value to harvested urine

Use it to grow fish.

5. What is the mineral distribution in the diluted urine (1 urine:3 water)

The average nutrient content of urine is Nitrogen - 5 g per person per day and Phosphate - 0.5 g per person per day.

6. How does one arrive at the market value of the added value of both human waste respectively.

We can grow Diatoms upto 12 times the N content, i.e., 60 g per person using the toilet per day. This would increase fish weight by 6 grams per day.

If fish are harvested at 1 kg weight and sold for Rs 100 per kg, the income would be at least Rs 200 per user per year. The actual income is more since fish feces too is recycled in the ponds ( 60 g - 6 g mentioned above ).

Regards

Bhaskar