This is great, but what happens to the sachets? Are the biodegradable? When I was in India a few years ago I was struck by all the newly introduced non biodegradable packing strewn about EVERYWHERE. The old unfired clay cups used by road-side tea vendors were great, but they were rapidly being replaced by little white plastic cups. Plastic is a scourge on the land and water resources.
I agree with your observation of India but note that biodegradable packaging has to be looked after or else it degrades before you’re ready. Think of flour packaged in paper: it is in fact sold that way in some places but it leaks and if it gets wet the flour is ruined.
This is a product designed for somewhat demanding conditions.
If anything your good argument really asks why a more biodegradable approach is not used in places that could afford it (I don’t mean economically but in “having the affordances for”). Western countries can manage to reliably package and use flour in biodegradable paper packages, why not other products? And the plastic bags that are a scourge upon the landscape not just of India are formthe most part not really needed.
I wonder how long it'll take for a plastic-eating microorganism to evolve.
Apparently trees evolved hundreds of millions of years before the bacteria that can make wood rot arrived, so you probably had piles of dead trees everywhere for such a long time.
Paenarthrobacter ureafaciens KI72 also know as Nylon eating bacteria can eat Nylon. I am not a biologist so I know little more about it than what I read in [1].
Do you happen to know what percentage of trees are from CO2 and what from the soil? I’ve always wondered how much carbon is captured in, say, a book, or a dresser
I don’t know the exact number, but came across a wild thought experiment a while ago that drove it home. Look at a big tree. There’s 3 things that could have gone into making it: water, air, and earth. If you look at the ground around it, there’s no hole where the tree grew. Sure, there’s the root system, but there’s nowhere near enough dirt missing to have made both the root system and the 50’ above-ground portion of the tree. That only leaves air and water.
Dry wood is about 50% carbon, 41% oxygen, 6% hydrogen, and 3% trace minerals, so it's probably safe to say that over 50% of it comes from CO2, and the rest from water and soil.
Edit: I misread what you said. I think you are claiming that because there is so much carbon and oxygen, probably more than half comes from CO2. But there is both carbon and oxygen (well really, air) in soil. Although apparently the concentration of CO2 in the soil's air is much higher than it is in the normal atmosphere, so it's possible your statement is correct. (Plus looking at dry wood composition is a bit odd when it's generally less than 15% moisture content - that leaves out a lot of water that's present in a living tree.)
Dry mass is typically used because it's consistent. Trees fluctuate over the year, being drier in some seasons than other. But they'll have the same dry mass.
Trees are mostly C6 H10 O5, coming from CO2 and H20. Based on atomic weight about 70% of the mass of the dry wood comes from CO2. Fresh wood will have extra water content, taken from the soil (though that water came from the air too).
There is carbon in the soil, but most plants don't take carbon up from their roots meaningfully. Nitrogen, phosphorus, potassium, and other trace minerals. Decomposers like fungi, bacteria, and insects will eat the carbon in the soil and release CO2.
I’m no ancient tree expert, but I imagine they’d eventually be buried under layers of new soil, washed away, or be swept along with geological movements
What do you think “new soil” is made of? The original trees evolved in a soil with different composition from the soil we have today (which today includes the consequences of decomposition of... trees).
I mean sure some of that could happen due to a bit of wind, so you’re not at all wrong. But the volume of thick loamy topsoil isn’t mostly tiny rock grains (sand) but a living amalgam of bacteria, fungi, plant matter, plantae, animal detritus (faeces but also cast off skin or carapaces...).
Part of the problem with modern farming is that parts of the economic process treat the soil as an inert matrix (just as road bike manufacturers justifiably (in their case) don’t spend time thinking of the road as part of the bike system).
I would argue that this is a situation where the (presumed) greater expense of a biodegradable sachet would not be worth it. When it comes to providing safe drinking water, I would want the cost to be as low as possible.
This is amazing. As someone who has lived in conditions where safe water isn't freely available, this costing 3.5 cents and being manufactured in an emerging market is life changing.
There seem to be two main use cases for this stuff.
One is everyday disinfection of drinking water. For that purpose a large container might be more economical, provided that it can be kept reasonably watertight through three years of daily use. (1 gram per day per family means a 1kg container will last 2-3 years.)
The other is emergency use in disaster zones for a limited amount of time. For this purpose a bunch of sealed sachets is much easier to transport and distribute despite the high unit cost.
$0.035 to clean 10 liters of water is very good. $35/kilo doesn't seem unreasonable given that chlorine itself is $16-$22 a kilo through consumer stores.
Given that these are pretty gnarly chemicals in bulk, I don't think you want users handling them. Training users on PPE and procedure and supplying the PPE is a whole mess.
Don't really need any special ppe for hypo and ferric. They're common industrial water treatment chemicals, meaning they're handled daily by low skilled workers without much news of accidents. There aren't even any special containment requirements for small quantities <500 gallons. Crystalized these chemicals are very stable and represent low risk to operators.
As a yard stick of cost: surface water treatment costs somewhere in the neighborhood of $1/1,000 gallons in the developed world.
I have recently acquired a small swimming pool, and my wife has taught me the expression to “flocc and shock” for removing debris. This appears to be the etymology
“Flocculant” isn’t a product name, it’s a description of the function of an agent (like a “detergent” that makes a liquid less turgid). A flocculant will clump the fine particles together so the clumps will be large enough to be strained out.
We definitely don't make any profit from this and while I'm not familiar with the financials, we do donate these products as part of our CSR and for disaster relief operations.
I’d be curious to know what percentage of the cost is the packaging.
Also, a link to lab results would be great. The article (but not the official website) says it removes some heavy metals. I wonder in what concentration, and which metals.
Also, how does this compare in cost to a softener + carbon + uv/chlorine?
Anyway, this looks like a fantastic technology. Thanks!
I worked as an extraction metallurgist in semi desert mines and we used an aluminium based flocculant (alum) to clarify water in dams with rotating stirrers.
Quite an old concept and not expensive.
Yes - many years ago when I lived and worked in South Asia, it was common knowledge that swishing a lump of alum around in your bucket of dirty water would help to settle the sediment.
Obviously it doesn't provide total purity, but it was a lot better than doing nothing.
Here in Thailand they sell those chunks of alum at village shops. Called สารส้ม in Thai. Villagers follow the same routine, swish it around in a bucket of dirty water to settle it out. Photo on the page at this link: https://pantip.com/topic/38053321
My guess is if you're posting here you're not necessarily the target market for this product. You might be better with just a Sawyer squeeze or other off the shelf filter. If you're looking for clarifying turbid water you could get a bottle of alum from the grocery store and use that as a flocculant. Or if you wanted heavier duty there's "Water Wizard for River Runners" which is made of stuff which is often used for wastewater treatment.
If you’re in the US or Canada, you probably want something else for water purification in your emergency kit (iodine or a good filter or the equipment to boil water)— bleach (including the calcium hypochlorite in this stuff) won’t adequately kill Giardia cysts or Cryptosporidium.
When my scout troop is teaching the Emergency Preparedness merit badge, we often do an exercise on bulk treatment of water beyond what is practical to filter with the portable filters we take on backpacking trips. We use alum as a flocculant, then sand to filter, then battery-powered UV sterilization (while noting that leaving clear water out in full sun for a few hours will accomplish the same dose as stirring a UV lamp through a bucket for a minute or two). Alum isn't exactly a common household item these days and the UV lamp certainly isn't, but it does make for a cheap and compact kit that can treat a lot of water with relatively little time and effort.
My point was more that it isn't something people are likely to already have on hand at home. It's certainly readily available and extremely cheap for this purpose, but you need to actually buy some before a disaster hits.
You could also ask your local water provider what their emergency plan is. Some parts of their emergency plan are confidential, but they are required by law to have a plan. The larger operators already have their Risk and Resiliency plans in effect, and smaller operators have a July deadline for their R&R plans.
It's been my experience that water operators take a lot of pride in their work and are happy to educate the public about what it is they do.
I'd rather prepare myself than rely on my provider's emergency plan. I can be sure if my house survives the disaster and I have my own purifier (whether this product or something else), then I'll be able to have drinking water. But even if my provider has a great plan, disaster plans aren't truly tested until the disaster strikes, so that plan may not be sufficient.
I have both stored fresh water as well as a filter in case of emergency, I'm not counting on my local water authority being able to pump water uphill to where I live for long during a disaster.
That's wise. Still curious what local utility says. Might be eye opening. I used to supervise a treatment plant, we were well prepared to deal with disasters.
FYI a flocculant can be used to settle out really dirty water, it needs to be mixed well to work correctly. Flocculants include ferric and alum. Bleach is typically used as a disinfectant to reduce bacteria and viruses. Oocysts are not destroyed by chlorine and have to be filtered out. Most surface water treatment plants use sand filters. Granulated carbon filters are increasingly common to remove trace chemical contaminants, but these will also adsorb chlorine, advise disinfectant after the filter step.
Water purification tablets are either chlorine (most common) or iodine based. So essentially this is the equivalent of a chlorine based tablet plus some flocculent to cause sediment to settle out of the water.
I don't know the cost of lifestraws to NGOs, but I guess they're more expensive. And you need one lifestraw per person, where these sachets can do bulk buckets of water.
Each sachet of P&G™ is provided to global emergency relief organizations or non-governmental organizations at a cost of 3.5 US cents, not including shipping from Pakistan by ocean container. Transport, distribution, education, and community motivation can add significantly to program costs. Sachets are generally sold at product cost recovery for 10 US cents each, for a cost of 1 US cent per liter treated.
10 cents for 10 liters, or a penny a liter. still a lot more than 3.5 cents, but not crazy.
Great idea. What are the sachets made of though? Lined with plastic and destined to be burned on cooking fires and ditches along with all the other single use, single serving P&G product plastic packaging formats targeted at the developing world I'd wager.
In developing country contexts the figures are easier to calculate than people think, due to the fact that functioning recycling and waste management systems are rare. Plastic waste improperly disposed of tallies almost 1:1 with production, and most production is carried out directly or on a contract basis by auditable multinational corporations.
Thanks for educating me about Amdahl's law. Some interesting reading to do around that.
I wasn't really saying either, but it certainly won't desalinate water. I was saying that almost all water this would be used on will contain dissolved salts, so that asking "what about water with dissolved salts" is moot.
Potable Aqua will not remove sediment from the water, if you use it to purify muddy water, it will still be muddy but without bacterial/viral contaminants. So you'll still be drinking whatever contaminants (heavy metals, etc) that are making the water muddy. So you'd still want to filter dirty water before drinking (and to remove cryptosporidium cysts which are not killed by Potable Aqua)
The flocculant agent in this product binds with the sediment, making it easier to filter out with a simple cotton filter.
That's probably not a fair comparison, there's only 20mg of the active ingredient (Tetraglycine Hydroperiodide) per purifying tablet and has expensive packaging and marketing costs.
Admittedly, I don't know how much that ingredient costs in bulk, but I bet if an agency wanted to produce it in bulk for widespread water purification, it'd cost a lot less than 50 cents/L
-Multiple steps are necessary—requires training or demonstration
-Requires a lot of equipment (2 buckets, cloth, and a stirrer)
I think this gets at the heart of the issue. If stiring in a powder and straining your water to prevent disease and parasites is too complicated to understand or too time consuming to do consistently, imaging how difficult it will be for these people to build water treatment plants and ultimately build an industrialized economy. Which is why they haven't done so while other nations did it without any assistance centuries ago. There simply is no easy solution to poverty in the third world, and obsessing over it will get you nowhere.
