Water filter for herbicide/pesticide/fertilizer?

"I thought I read somewhere that the First Need purifier was capable of doing that?"

Yep. See http://www.rei.com/product/851771/first-need-xle-elite-water-purifier
I've used this 16oz filter with some gross water and was amazed at the results.

Good luck with water,
-Barry

"with some gross water"

What kind of water was it?

–B.G.–

I do not see that General Ecology's own site makes any claims about the First Need purifier being effective against herbicides etc. Perhaps I'm just blind.

http://generalecology.com/category/portable/product/first_need_xle_portable_water_purifier-new

The First Need will treat for viruses – with a chemical medium. It does not (nor does anything other than reverse osmosis) remove any chemical whatsoever.

^^ This. The other answer is incorrect and potentially dangerous. Porous filters do not remove dissolved liquid chemicals from water, period. You really don't have any options for backpacking use, unfortunately. You're better off packing in all your water or going somewhere else.

“I do not see that General Ecology’s own site makes any claims about the First Need purifier being effective against herbicides etc.”

The SeaGull IV model has a Product Data Sheet detailing the removal of many chemicals. (Found via ‘Test Data’, at the bottom of each page.)

I have sent an email asking for information about the substrate used in both the Seagull and the First Need, and if a Data Sheet is available for the First Need.

I think that you will want to have a filter that uses Active Charcoal as part of the filter matrix to absorb the chemicals that you are dealing with.

I think that the old MSR hang pump filters have active charcoal in their core.

MSR Mini Water Works?

Alternatively, I had a charcoal filter hooked up to my Sawyer Inline filter for chemicals.

Not elegant, but was kind of workable.

Tony

This is part of my day job.

Granular Activated carbon (GAC) will adsorb pesticides and herbicides from water. A Brita filter element is the most widely available packaging of GAC if you can find an UL way of feeding water through it.

In-line carbon filters go slowly at Sawyer squeeze pressures, but given time, would work fine in line with a sawyer inline particulate filter.

Cheapest is to buy your GAC in the aquarium aisle at the pet store. Cut the bottom off a plastic soda bottle, lay mosquito fabric or screen-door screen across the "bottom" (the old top), fill with GAC and pour the water through that. That would be way overkill. For a week of drinking water, a tube 1" in diameter and 8-10" long would be plenty of GAC and give plenty of contact time.

Fertilizers are salts of nitrites, nitrates, phosphates, etc and can't be removed with GAC. That requires RO, distillation, ion exchange, or biological treatment.

+1 for Tony's and David's comments. Reducing the concentration of organic solutes in water is very easy with activated carbon. This includes basically all agricultural pesticides. The First Need is one of many filters that contains activated carbon, so it will reduce the concentration of any herbicide or insecticide (except boric acid, which has very low toxicity anyway).

The First Need filter also has an electrostatic matrix for capturing anions. This is how it captures viruses (which are anions).

The two most widely used herbicides in the world, 2,4 D and glyphosate, are soluble in water and anionic. So, the electrostatic matrix in the First Need filter would capture these. Most agricultural insecticides are not water soluble, though. The pyrethroid, organophosphate, and organochlorine insecticides hardly dissolve in water at all. So there shouldn't be much of these in your water source anyway. Neonicotinoid insecticides, like Imidacloprid, are water soluble but they are cationic, so they will be not be captured by the electrostatic matrix in the First Need filter, but they will be captured by the First Need's activated carbon.

So, any filter with relatively new activated carbon in it will remove herbicides and insecticides, and the First Need filter offers an additional level of protection by electrostatically capturing anionic herbicides like 2,4 D and glyphosate.

David Thomas is an expert on this.

You can also buy mesh bags at Petsmart/Petsco made to hold granulated carbon, like this:

http://www.petco.com/product/7363/Petcetera-Filter-Lifeguard-Bags.aspx

You could filter or treat the water (Sawyer, AquaMira, etc.), fill the bags with GC, put the bag into your water container and shake for a while. I have no idea how long contact would be needed between water and GC to adequately remove pesticides or herbicides. Anyone?

I bought supplies to treat water with carbon after using bleach, but just never got around to it b/c the Sawyer Squeeze came out and I like that.

Great stuff all around.

I think I'll go with David's pet store bottle method.

Does the order of filtering and purifying matter? Could I use a Steripen before or after and have the same results?

Thanks all for the contributions.

Edit for clarity – Could I use a treatment method after filtering through GAC and have the same results?

Personally? by the time I cadged together something out of parts and bags and pieces, I'd worry that I didn't do it right and since I have no way of knowing one way or the other I'd be scared I'll just poison myself. How long? How much? when should I drink it? Do I need to test it out on my friends?

I'll let experts fix my car and deal with chemicals. I'd just rent a mule and carry the water, or perhaps a sherpa, or bring a wheelie cart…

> Does the order of filtering and purifying matter? Could I use a Steripen before or
> after and have the same results?
Provided the water is clear, yes you can. The UV will not (of course) have any effect on dissolved chemicals.

Cheers

Interesting discussion.

Drinksafe systems (Seychelles?) filters claim to treat chemicals . I have no experience as rarely feel a need to treat water here, but they seem to be rated by many users.
http://www.drinksafe-systems.co.uk/products.php

You can use the carbon first and then use filtration, UV, boiling, iodine or chlorine to treat for bacteria.

You can use filtration or UV first, then carbon.

If you boil first, you'd need to let the water cool to whatever the plastic in your carbon container could handle (the GAC is fine at 100C)

If you use chlorine or iodine first, you must allow adequate contact time before then using carbon. Carbon adsorbs chlorine and iodine and would therefore stop the disinfection process.

If you don't want to do your own plumbing, you don't need to haul gallons of water at 8.3 pounds per gallon. Just bring the whole Brita pitcher with the filter element in it. About $25 and maybe a pound.

Brita also makes water bottles with carbon filters in them. $14.01 for two with free shipping from Amazon Prime.

Aquarium grade granular activated carbons are typically quite dusty, and need to be rinsed well prior to use. Personally I would run the water through carbon first, then mechanically filter it to eliminate the particulates from the carbon.

Find some place to go where you don't have to drink agricultural run-off

Hey David,

Here is the Brita filter element that they use in their bottles.

Assuming I can attach some narrow tubing (another aquarium product?) to the top, would this do the trick?

I could use the Steripen to treat the water, then drop the carbon element inside and drink from the tubing. Doesn't seem like it'd add a lot of weight, maybe a few ounces?

From several posters:

“What kind of water was it?”

It’s hard to tell with my pics, but this lake in southern Indiana had a whole bunch of dead fish floating on top:

Then in a River to River trail in southern IL, the water was pure green and stagnant. Sorry, I can’t find my picture of it. Each time, the water came out clear (with a First Need). Plus, I’ve filtered root beer and it came out crystal clear BUT a little corn syrup was still left in the water — yea, I was curious.

“The First Need will treat for viruses – with a chemical medium.”

No chemicals in a First Need.

Good insight from Colin.

Here’s the difference between making your own GAC (or using a Brita element) and a First Need. The GAC will still let color through (lake tannin) but the First Need won’t; a very nice psychological bonus for those of us who still can’t drink brown water. And how do you know your GAC is working? How do you know it wasn’t dropped and cracked? How do you know it didn’t freeze in the middle of the night and cracked? It would have to be sent to a university lab to really check. But with the First Need you can check at home (or on the trail) for breakage. No other mechanical filter can claim this.

-Barry
-Keep on drinking

In my post above I wondered if the First Need used the same media as the Seagul, for which there is a Products Data Sheet. I got a reply from General Ecology and the Answer is Yes –

"In response to your inquiries – First Need Systems share the same purification technology as our Seagull® IV water purification systems. The same contaminants are proportionately removed by First Need systems but at the slower flow rate and capacity of that system."

"General Ecology, Inc.’s proprietary “Structured Matrix™” technology includes Microfiltration, Chemical Adsorption and Electrostatic Attraction in order to remove microbiological, organic chemical and aesthetic contaminants from the water."

A hypothetical: You are in an area with agricultural runoff and you don't have a filter. Are some of these pollutants more volatile than water so that, worst case, you could boil creek water for an extended period to evaporate at least some of them before drinking?

Don't know for sure, but I doubt it. Now, you might be able to rig a still to capture the water vapor that boils off and condense that to get clean water…probably not without leaving ultralight far behind.

> Are some of these pollutants more volatile than water

NO

Cheers

Generally, no, you can't boil off ag chemicals. A few chemicals I deal with, benzene for instance, are volatile enough to boil away, but simply aerating would remove most of it, too.

Kelly: yes, you could suck through a Brita element to address organic chemicals.

Tannins are adsorbed onto GAC. In my kitchen. And at that former lumberyard with the spilled fuel – we used thousands of pounds of GAC to treat the groundwater as it flowed down gradient. We wished it didn't adsorb tannins because we had to use a lot more GAC to still have the absorptive capacity for the benzene, toluene, xylenes, etc.