Urine waste management from compost toilets and enzymes

Hello, Maybe someone has experience with managing/composting/neutralising the urine from compost toilets, let me explain before you answer.

I think we are all familiar with the standard techniques of deluting urine with water, not seperating urine from the compost toilet but keeping it together and composting it together, sending the urine to bushes and trees or various evaporation techniques but I'm asking something completely different.

Has anyone experimented with using enzymes for neutralising the acidity and smell of urine? I've tried all the other methods with good success and now i would like to look into the use of enzymes. If anyone has experience to share or knows of useable studies done on this subject and or has intelligent information to share i would greatly appreciate to hear from you.

Best regards
Davide

Hi Davide,

Just looking for some clarification; my understanding is you're looking for an enzyme additive to add to a composting toilet system that combines urine with 'the rest'.

So you're looking for an additive to help with the smell. What is the end use/location of the composting toilet collection? Do you add anything already? Such as a carbon source (wood shavings?). What is the turnover rate for your current system?

Ashley Cottonwood wrote:Hi Davide,

Just looking for some clarification; my understanding is you're looking for an enzyme additive to add to a composting toilet system that combines urine with 'the rest'.

So you're looking for an additive to help with the smell. What is the end use/location of the composting toilet collection? Do you add anything already? Such as a carbon source (wood shavings?). What is the turnover rate for your current system?

Hello Ashley,
Not exactly. Currently I'm separating the urine and looking to treat it separately, possible with enzymes. The solids are composted using traditional methods with great success. I would like to reduce the urine imput in my composting piles to reduce the nitrogen levels.

Hi I've been using a compost toilet for 5-ish years now. I just have the old bucket setup. I used to separate the urine but now I don't.

My best results for curbing urine smell has been regularly soaking buckets in a PBW solution between uses, since I have a rotation of 3 buckets so they can be cleaned in dried and ready to go. If you're unfamiliar PBW is a brewery cleaning powder that is powerful but grey water safe. Some people say that oxyclean is pretty much the same, but I beg to differ. I work at a brewery and I find it to be far more effective.

I've found that after a while the smell will seep into the plastic and it doesn't matter what I add to the toilet as soon as it gets wet again it starts to stink.

I am however experimenting with adding a wee bit of greywater holding tank enzyme to my bucket see what happens.

Happy Composting!

We have run lovely composting toilet setup, using sawdust we get free from a local lumber yard. It's all pretty fine sawdust from green sweet chestnut coppice.

We have NEVER had issues with smell due to urine etc... provided a sufficient amount of sawdust is being added to the bucket regularly. There has been no need to divert urine and process it separately, and the urine ensures that the sawdust makes for a very hot composting process with neutralises everything in a matter of a few days.

The permaculture approach her is "the problem is the solution" - your current system has an issue with too much urine for some reason, but the nitrogen in urine is incredibly valuable as a nutrient and makes good compost. Using an enzyme to break it down (presumably back to atmospheric nitrogen?) is essentially looking for a waste disposal system for urine.

Maybe flip your thinking round. How can your redesign your system to get maximum use from the urine, so it isn't a waste to dispose of?