Extracting the urine, suggestions?

[Justme]

No really I am extracting the urine & need suggestions.




So after two years of using a bucket & chucket / composting set up with no urine separation its now time to build two separation units.
I already have two separation seats that I am going to mount under a nice wooden top.





My big question is how will I stop smells from the urine pipe coming back up the pipe?
I did think about using a trap of some sort but that will just fill with urine & then smell. I have also heard that people use a trap but put some oil in it to float on the top of the urine to seal it. It would also be possible to "flush" the unit using a beaker of water but that would rely on people remembering to do so.
I guess we could also use urinal blocks of some sort but they would need to be "green". The green ones I have found are about £3 each inc del.

[EccentricAnomaly]

The waterless urinals at CAT use the oil floating on top method. Might be worth having a word with them.

[guydewdney]

what about the waterless urinals in pubs - they have a sort of green rubber disc with holes in.

[Justme]

what about the waterless urinals in pubs - they have a sort of green rubber disc with holes in.

They seem to come in 3 types

1, using a alcoholic oil that you replace as needed
2, using replaceable cartridges
3, using "silver" tec that is impregnated in the actual urinal

All seem to need a plethora of chemicals to clean it quite often.

The oil used in type 1 costs £70 per US gallon but not found it in the UK yet, carts wont work nore will the silver tec.

Other suggestions have been

using a valve that is operated by the user sitting or the lid
a trap with oil
using a vent stack

and a few more, all have merits & down sides. Keep the ideas coming.

[mespilus]

There must be some way of making a vapour lock
with a buoyant ball, (table tennis ball?),
which floats on the water/urine mix in the 'u'-bend.

There is a fixed upper position of the buoyant ball,
probably by a reduction in size of the pipe diameter,
such that the buoyant ball is in (annular) contact,
forming the vapour lock,
with the smaller diameter pipe when floating on the contents of the  'u'-bend.

When the urine accumulates in the liquid part of the toilet bowl
the mass of the urine forces the buoyant ball down releasing the urine through the 'u'-bend.

[johnrae]

On a visit to Yosemite park in the states I noticed they had "dry" toilets which did not smell .  This was achieved by simply fitting a tall chimney stack (at least 12 feet high and around 8 to 10" diameter) to the underseat chamber.  The stack created a natural draft which in turn created a partial vacuum within the soil chamber which was balanced by fresh air being drawn down through the toilet seat.  Hence no smell came up from the toilet.  Very simple and extremely effective.  No fans, no chemicals, no running costs.

[Justme]

I do like the ball idea. Not quite sure that you could get the liquid level, pipe taper & ball to seal with just enough pressure but can still be pressed down by a small amount of urine above it. If any stays above the ball it will smell. Also all the extra bits will build up "salts" & need regular cleaning to maintain operation.


The vent method works well for non separating units as you want the air flow from below the seat. It wont help keep the urine sterile till its out of the pipe system or stop build ups. Plus I dont really want yet another hole in my brand new roof.


The more I look at this the more I am inclined to go simple with either a manual water flush using a beaker or a spray bottle with a water / additive mix. Backed up by a daily or weekly hot water flush. Keep the pipe work steep to stop residues, possibly using the sink waste to add water to the pipe to flush it. Might even be possible to fit a water rinse / flush system from a caravan portapotty.

[wookey]

How about simply using a HepV0 straight-through trap?
http://www.plumbworld.co.uk/hepv0-self-sealing-waste-0-4439

Pretty-much perfect, I'd have thought.

We've been on bucket+chuckit (into the compost unless the weather is Oh, how I wish it was better), as you so nicely describe it. Where did you get those separator seats? And where do you pipe the weasel pee to?

[Justme]

How about simply using a HepV0 straight-through trap?
http://www.plumbworld.co.uk/hepv0-self-sealing-waste-0-4439

Pretty-much perfect, I'd have thought.

We've been on bucket+chuckit (into the compost unless the weather is Oh, how I wish it was better), as you so nicely describe it. Where did you get those separator seats? And where do you pipe the weasel pee to?

That part looks like it might do.

The seats came from linky

At the min the urine is going on the compost in the bucket. We want it to go to the grey water system (to get diluted) that helps water the growing area.

[jackal]

Hi we have a separett and that don't smell  so I don't see an issue unless the system you have is inefficient. We also have a simple compost toilet outside and built it using the draft principle you find on chimneys. It works very well and doesn't smell or have any problems with flies even though we have a farm house and cattle.

Good luck

[Justme]

Well its been up & running now for a few weeks. We had guests so there was 4 adults & one child. The urinal bit dint smell at all but we do give it the odd squirt with water / citronella mix. Did have smells from the other bit but one of the guests was not following the instruction to saw dust it & was covering it in toilet paper instead.

Emptying it is now much much easier, less often even with the guest than before.