DISCUSSION

Urine diversion or urine separation?

via email, Oct. 9, 2001, 17:11

Urine separation and urine diversion are two different things. You can separate cream from full milk but you cannot separate urine from human excreta once the urine and the faeces have been mixed. What you can separate from the mixture is a liquid, but that liquid is not "urine".

Uno

via email, Oct. 10, 2001, 10:02

your comment is convincing, but also confusing. To my knowledge, urine separation is a widely used term in the community of ecological engineers, and it's used by many to describe the separation of the two excreta fractions in the toilet bowl. I have never heard it being used for the separation of a liquid fraction from a mixture of feces and urine.

Thus, in my view, urine separation and urine diversion are used as synonyms. Isn't that the case? Håkan used the term urine separation as well in his article. Can you clear this up for me?

Andreas

via email, Oct. 10, 2001, 11:42

The fact that a term is widely used in the community of ecological engineers does not mean that it is the correct term. Sanitary engineers always talk about 'sewage disposal'. They have heard it and used it so many times that they believe that the problem they are going to solve is defined by these two words. But, as I have said many times, the human body does not produce 'sewage'. Sewage is the product of a particular technology, of a particularly unfortunate technology. And in a closed system nothing can be permanently disposed of. You can move it and hide it, but not get rid of it. - Muddled thinking results in inappropriate solutions.

Back to separation vs diversion. - You separate what is mixed or joined. If it is not mixed or joined there is no need to separate. The human body does not mix urine and faeces. They leave the body from different openings and in different directions. If we want to process them separately, which makes sense considering their quite different properties, we should not mix them but instead divert them away from each other. This results in a specific set of technical solutions and processes. - For various reasons we may decide to go against nature and mix urine and faeces. If we do, there is no way we can separate them again. We can separate liquids and solids, but not urine and faeces.

Of course we can say like Winnie the Poo: 'When I use a word it means exactly what I want it to mean when I use it'. - A charming idea.

Words influence thinking. Thinking influences technology. Technology affects ecology. Words are important - also for ecoengineers.

What term would you use to describe the separation of the liquid fraction?

Håkan is using 'urine separation' because he believs that this is the correct translation of the Swedish term 'urinsortering'.

Uno

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