[ho !sheep!]

Moving forward with horse racing rehabilitation centre we have plans for a water walker that uses salt to generate chlorine via electrolysis. The problem is once full of horse poo we need to get rid of the water. The prodjected bills for waist water where eye watering. So as we will be getting more sheep ? and salt Marsh raised lamb is supposed to be extra tasty I'm thinking about spreading the water on some of our land. There arnt any streams to worry about. So what do you think ? and where can we get salt tolerate grass?

[Possum]

Interesting idea but I think salt marshes need to be coastal. As far as I know, they need twice daily tides in order to maintain a healthy ecology.

[Womble]

  OK, now I'm really confused!  .

we have plans for a water walker that uses salt to generate chlorine via electrolysis.

So a water walker is like a regular horse walker, but in a sort of swimming pool arrangement, right?

Then the chlorine is presumably being added to keep the water sanitary?

Therefore what the chlorinator is doing is using electricity (electrolysis) to split common salt (Sodium Chloride) into chlorine gas and presumably sodium hydroxide (caustic soda). So is the water itself kept salty?  For example, does the electrolysis happen directly in the pool, or does it happen in a side-chamber, with only the chlorine going into the pool?

I'm sure this will sound like a digression from your original question, but whilst the chlorine will escape, the sodium has to go somewhere, so I'm not sure it's as simple as spreading salt water on the land, because half of what made the salt (the chlorine) has disappeared, and there could be other salts present due to the need for pH correction, unless I'm missing something somewhere.

Do you have an expected concentration analysis for the pool water and any effluents?

[arobwk]

[member=169267]ho !sheep![/member]

I'm sure you didn't literally mean   "... once full of horse poo ..."  !!! 

Anyway: clearly you are thinking laterally, but I would seriously recommend you talk to the Environment Agency before you commit to spreading "the water" on your land (with or without "Salt Marsh" sheep being grazed). 

It sounds to me like something that could end up with a hefty fine for pollution if it's not been "approved" as an acceptable waste management arrangement. 

[ho !sheep!]

I'm thinking some kind of boi filter in form of a salt Marsh to remove the poo and salt running back into land drainage to a tank for recycling, we plan fit a horse walker that has water in it that comes up to the horses knees this is why we will have more waist salt water than we can dispose of without a licence and huge bills. The development of the horse therapy center is how we pay the bills. Farming is more of a side line that helps us tick boxes with planing requirements. 2x day discharge over the adapted feilds would be easy to do. We do a massive amount of rain water capture as the current hydrotherapy kit we have for the horses needs changing after each horse though this water is not chemically treated at the moment if we fit the water walker we will actually use less water just need to be able to separate out the salt before we can recycle it. Hope my idea makes more sense now.

[ho !sheep!]

Chemically once the water has no current running though it the chlorine brakes down back in to salt - one chloride no gass is give off and no caustic soda is created if it was it would kill the horses and a lot of people too pH sits between 6.4 and 7.5. We control this with how much salt we add, and yes there is quite a lot of poo in it after 6hrs of horses walking round and doing what the do well poo where you would rather they didn't. it blocks sand filters in under 6mths. back washing the filters helps but you have to take it all out by hand compost it and spread it or pay to flush it down the sewage system. Nothing will just be done without approvals not wort it just thinking there has to be a better way to make use of the water and waste. Than pay for it to go down the drain.

[Womble]

Chemically once the water has no current running though it the chlorine brakes down back in to salt - one chloride no gass is give off and no caustic soda is created.

So are you saying you don't have to add any acid at all? I had expected you'd have to put hydrochloric acid back in to lower the pH again, and to replace the lost chlorine (enabling the sodium hydroxide to be turned back into salt, as you say). If the system doesn't do that, I'm definitely missing something somewhere.

There are lots of good ways to separate solid poo from liquid water though. That would then give you a clean salt water stream back for re-use. Environmentally, I think you'd have to use some sort of closed loop rather than putting anything on the fields, as I'm pretty sure this would be counted as a release even if you ultimately got most of it back again.

It all sounds like a really interesting setup. Do you have any blurb from the suppliers that you could share? 

[sheeponthebrain]

why not grow foddet beet? i believe it thrives in salty ground.  you could spread the salty water on it all through the growing season id pressume

[ho !sheep!]

I had posted a reply but it has disappeared in the opps no WiFi I think.
https://www.cat.org.uk/info-resources/free-information-service/water-and-sanitation/sewage-treatment/
This has some helpful information in the my recerch so far.
Basic salt choline generator info https://autopilot.com/how-does-a-swimming-pool-salt-chlorine-generator-work/ the more advanced ones disovle the chlorine gass and it gets used in the pool sanitisation of the filters. This more advanced system is the type we want as our pools are in barns so we can't vent the gass safely.
The beet crop isn't a bad idea. Thanks Removal of just the solid poo without a filter that needs renewing would be helpful but they pee in it too. And that over time dose mess up the pH and ability to generate the chlorine. The more I read the more options there seam to be but it's very confusing.

[Buttermilk]

People use salt to kill plants do they not?  I think dumping salt water on an area of land will kill off the herbage that is growing there.

[arobwk]

I knew nothing about equine water-walkers until now:  I’m intrigued by the waste issues they generate and so I followed the links you offered [member=169267]ho !sheep![/member]  However, I’m not a lot better off from viewing the web-sites.  So bear with me while I try to deconstruct your issues & objectives.
 
Firstly, your problem is the high cost of ‘disposing’ of contaminated water waste via the sewers;
 
But also, filters become well congested with solids and there are issues related to practical cleaning operations;
 
And so, how to dispose of (recycle) contaminated water without incurring sewage costs and how to minimise filter clogging/cleaning.

 So:
 
My 1^st thought is that water-walker manufacturers are fully aware of the issues and surely would have worked out and be offering complete enviro’ friendly and cost-effective solution/s already if it was “easy” !
 
My 2^nd thought is that you need to minimise recirculation of water during horse-walking operations:  in other words, you need to be able to refresh the vast majority of water during horse/s walking session/s and divert contaminated water (particularly as regards solids) without the need to re-condition the solids contaminated water immediately through the chlorination plant.

 My 3^rd thought is that my 2^nd thought will require a very very large reservoir of ‘salted’ feed-water to keep the horse walker supplied through a chlorination unit without having to rely on immediate recirculation/filtration/re-chlorination of contaminated bath water.

 Am I getting a little bit closer to understanding your problem/objective ??

 

[ho !sheep!]

Your 2nd and 3rd thoughts are very correct the main manufacturers just use commercial human pool filters they just aren't designed to handle the volume of solids from 60+ horses our yard is expanding to 120 horses.
Most systems are currently set up for 6 horses a day and the use of horse nappies unfortunately many of the horses we have come to us who would use the water walker most come with back injury or hind limb injury that makes it impossible to fit the catch bag nappies.
So we have the issue that we pay for the the desposal huge volumes of water that we can't capture from rain water fast enough to replace it therefore having to add mains water and the cost. Or coming up with a far more environmental friendly recycling system. We can add more storage tanks that's the easy bit but even just removing the solids and recycling the salt water we have to discharge about 15% daily. It takes 72hrs to desolve enough salt to start with system up from fresh tap water not OK as we need to run the walker every day our contract for the extra boxes and horses depends entirely on the installation of the water walker it dubbles our capacity. This does mean that financing the prodject is more than manageable if we can control the ongoing operating costs for water consumption and disposal we generate the power we use from solar and wind. Our aim is to be as self sustainable as possible while we aren't a small 40 acer farm we are very much new to farming and learning alot far faster than we often wish we had to our crop area is all contracted out we just don't have the skills or kit to produce our own feed for all the horses and other critters we are introducing to the farm.

[Womble]

the main manufacturers just use commercial human pool filters they just aren't designed to handle the volume of solids from 60+ horses our yard is expanding to 120 horses.

OK, so that says to me that you need some sort of pre-filtration before the water gets to the standard poo(l) filters. Something like this vacuum drum filter might do the trick (though hopefully a smaller version):



Then you'd need a method to control the concentration of urine in the water. Off the top of my head, I can't think of a way to do that without also removing salt, but the first thing to do would be a "mass balance" to work out what the required purge rate (i.e. offtake and replacement rate of water), to keep urine and other contaminants at or below acceptable levels.

So effectively what I'm saying is:

1) Remove the majority of the poo, using something like the rotary filter shown above
2) Remove the rest of the poo using the manufacturer's pool filters, perhaps with additional sand bed filtration upstream to improve their lifespan and reduce maintenance
3) Continuously purge (remove) a percentage of the water from the system to keep urine levels under control. The key here would be to minimise the quantity of the purge, since that's what will cost money.
4) Get rid of the purged water by:
    a) Using your original salt marsh idea if possible.
     b) Paying for it to be disposed of
    c) Concentrating it up to reduce its volume, then disposing of it (this would be like b, but hopefully lower cost).

As arobwk says, the manufacturers would be the first port of call for this, but if they can't help, I think it would make sense to get some additional technical support, either to act on your behalf in thrashing out the technical details with the manufacturers, or to come up with a bespoke solution such as the one described above.

At the risk of crossing a line here, I am actually a freelance Chemical Process Engineer, and this kind of thing is what I do for a living. If / when you get to the stage of needing a design and cost for this, I'd be happy to talk further offline and give you a proposal for support and process design if that's of interest.

Cheers!

[arobwk]

Actually ( ) I didn't say the manufacturers would be the first folk to talk to:  what I had concluded was that manufacturers of horse-walkers are not really addressing the overall issues of operating a horse walker and certainly not at ho !sheep!'s volume. 

One needs to clearly set out engineering/environmental/operating cost (etc) objectives before approaching a manufacturer or manufacturers who are already missing the point/opportunities.

However, I would agree that any reputable horse-walker manufacturer would likely be interested in working towards a different solution with knowledgeable clients and engineers:  I've been there several times on new engineering projects, most notably with the sizing-up of surface-coating removal technologies to whole aircraft repairs and so I am quite confident there will be someone (maybe more than one manufacturer) ready to 'partner', repeat 'partner', system developments to everyone's financial advantage !


Good luck. 




 

[ho !sheep!]

People use salt to kill plants do they not?  I think dumping salt water on an area of land will kill off the herbage that is growing there.

Some plants like salt most don't that's the tricky bit choosing the correct pants to do the job