1. Overview

Urine disposed of in bio-toilets is processed as domestic waste. Urine contains nutrients that plants need to grow, so rather than process it as “waste,” we have undertaken to make effective use of it as a resource (fertilizer). To make effective use of it, it is essential to put the urine in a state where it is easy to deal with for people.
Bio-plants are devices that produce this state. (Chemical fertilizers have the problem of raw material depletion)
Bio-plants were patented in March 2019. (Patent #6496866)

2. State where urine is easy to deal with

  1. ① Devoid of unpleasant odor
  2. ② Aseptic
  3. ③ Colorless

3. Overview of the purification process

In the processing tank, urine is aerated and purified by bubbles containing ozone. The bubbles use UFB (Ultra Fine Bubbles).

4. Device configuration

5. Purification process

  1. ① 5 L of urine collected from bio-toilets and 20 L of city water are added to the processing tank (50 L capacity)
  2. ② Ozone aeration begins the purification process. The source of the aeration is ultra fine bubbles (UFB).
  3. ③ When the ozone monitor confirms ozone saturation, the purification process is completed. The processing time for 25 L of liquid is 9 hours.
  4. ④ Collecting the purified urine. There is no scum at collection time.

6. Process diagram

7. Sample test results
(sample test performed by Nagano Rodo Kijun Kyokai Rengokai, Suwa Measuring Post)

Collection from bio-toilets
Raw urine:
sample 8-1-0
Test criteriaTest results
Total nitrogen6,300mg/L
Total phosphorus300mg/L
Number of coliforms0/mL
General bacterial count120/mL
Odor concentration7,900
Odor index39
Before purification
5L of raw urine + 20 L of city water
Sample 8-1-1
Test criteriaTest results
Total nitrogen1,200mg/L
Total phosphorus58mg/L
Number of coliforms0/mL
General bacterial count62,000/mL
Odor concentration3,200
Odor index35
After purification
Purified urine:
Sample 8-1-2
Test criteriaTest results
Total nitrogen1,200mg/L
Total phosphorus60mg/L
Number of coliforms0/mL
General bacterial count0/mL
Odor concentration20
Odor index13

Please feel free to inquire
about anything that is unclear.

In order to respond to points of uncertainty, we have collected the questions we receive most often into a Q&A. Before submitting an inquiry, please check our FAQ page first.

We wish to spread this technology around the world. We can respond flexibly to the lateral deployment and export of this technology, so interested parties should feel free to contact us.