Pt.3 H2O /Nano Filters

Cheap Drinking Water from the Ocean

Carbon nanotube-based membranes will dramatically cut the cost of desalination.
A water desalination system using carbon nanotube-based membranes could significantly reduce the cost of purifying water from the ocean. The technology could potentially provide a solution to water shortages both in the United States, where populations are expected to soar in areas with few freshwater sources, and worldwide, where a lack of clean water is a major cause of disease.

The new membranes, developed by researchers at Lawrence Livermore National Laboratory (LLNL), could reduce the cost of desalination by 75 percent, compared to reverse osmosis methods used today, the researchers say. The membranes, which sort molecules by size and with electrostatic forces, could also separate various gases, perhaps leading to economical ways to capture carbon dioxide emitted from power plants, to prevent it from entering the atmosphere.

The carbon nanotubes used by the researchers are sheets of carbon atoms rolled so tightly that only seven water molecules can fit across their diameter. Their small size makes them good candidates for separating molecules. And, despite their diminutive dimensions, these nanopores allow water to flow at the same rate as pores considerably larger, reducing the amount of pressure needed to force water through, and potentially saving energy and costs compared to reverse osmosis using conventional membranes.

Indeed, the LLNL team measures water flow rates up to 10,000 times faster than would be predicted by classical equations, which suggest that flow rates through a pore will slow to a crawl as the diameter drops. "It's something that is quite counter-intuitive," says LLNL chemical engineer Jason Holt, whose findings appeared in the 19 May issue of Science. "As you shrink the pore size, there is a huge enhancement in flow rate."

A carbon-nanotube membrane (quarter shown for scale). The nanotubes are located at the center of each square. Despite their tiny size, they can filter water more efficiently than current larger membranes. (Credit: Science)

Interesting use of nanotechnology to help solve the problems with desalination. I always had the vision that many of the deserts that are close to oceans to be turned into vast areas of productive farmland or new cities built.

Another minor issue that has some interest in Santa Barbara is schemes to prevent water runoff and thus raise the ground water level by retaining water on the land.
One scheme that has drawn attention by a few of the city council members is semi-porous cement. One of the best filters to purify the runoff is the ground itself, but I think there are simpler and more cost effective ways to make a dent in reducing runoff.

My suggestion was to use Dry Wells to capture the runoff from rooftops and drain runoff. I presented it to my council person and showed how many of the gutters in town drain right onto the road or even worse onto the sidewalks instead of using the dry wells to capture the excess runoff. Here is a good diagram and instructions of the use of one:

And a cross section of one:

Gravel-less Drywell Leach Pit Kits

Grey water links:
CLOSED-LOOP MUNICIPAL WASTEWATER RECYCLING SYSTEM
Grey Water Systems
Recycling Gray Water for Home Gardens
ALTERNATIVE GREY WATER SYSTEMS
Less water than the Sudan?
Grey Water /Australia
Solving Problems with Nano-Filters

Carlsbad Desalination Project

HT Jason: Gates Foundation: 'We need to reinvent the toilet' - On The Left
Gates Foundation: 'We need to reinvent the toilet' - CNN.com

Water Conservation Part Two.

This post will be a compilation of water saving techniques and devices and not meant as a recommendation or endorsement.
I had heard of No-Flush Waterless Urinal for some time but just recently saw one at UCSB.

They all work like the picture below shows as I have seen. There are additional links for all items in the links section.

It works on a chemical trap (Blue Seal as above) that keeps the smell from escaping and the overflow spills into a normal drain as the trap is filled.

Not that the She-Pee Urinals will catch on except for remote/special events (How to beat the Glasto toilet horror). But this has not stopped the development of a P-Mate for Women that is a disposable cardboard funnel to allow women to pee standing up, and the P-Mate Urinal stalls.

Warning next link is graphic, that talks about Advice on how to Pee Standing up for Females.

So if there is waterless urinals how about toilets? Envirolet® Composting Toilets by Sancor™ uses a fanned aeration system.

And SunMar® self contained composters use a handled rotating drum (much as a normal composter does).

Lastly there are some basement types as in:
Waterless composting toilet systems make too much sense!! and Waterless Toilets. But I am not sure how the solid waste gets down the drain without water and thus defeat the benefits.

But one area that I feel would be good to use this technology is rest stops or public restrooms that are not high traffic areas. Waterless toilets or 'dry sanitation' systems has a couple of ideas on this:

If these techniques above did not reduce the smell from normal outhouses then maybe the aeration system shown above might also be a possibility.

Another technique that is much easier to implement is the Dual Flush Toilets. I first read about this in the 70's when it was being used in Japan, and is still the simple concept that if it is liquid waste and maybe a small wad of toilet paper then only a smaller amount of water is needed to flush the waste. According to the web site, average old toilets used 18.8 gallons per day and the new low flow ones are at an average of 9.1 gallons per day and their new dual flush is 6.9 gallons per day. Instead of legislating the low flow toilets I wish that congress had let the market decide on how best to reduce water consumption, but that is for another day.

And now for something completely different...

Art's glass toilet tests courage

An artist has created a usable public toilet in a glass cube to challenge the curiosity - and bravery - of people passing London's Tate Britain gallery.

Monica Bonvicini said visitors would have to "defy their own embarrassment" to use the minimalist cubicle, made from one-way mirrored glass.

It is impossible to see into the toilet, which will be free to use, but the person inside can see passers-by.

The work, called Don't Miss A Sec, uses a prison loo as a historical reference.

Clivus Multrum, Inc. manufactures composting toilets and greywater irrigation systems for distribution throughout North America and beyond. Please contact us to discuss your project in detail.

Links:
WaterLess
New way to go green: Waterless urinals make a splash
Case Study for Flushless Urinals
Composting Toilets
What is a Composting Toilet System and How Does it Compost?
Simple Home Repairs: Splash Blocks and Drywells
Dry Well-Wiki

In Colorado, Rain Barrels Are Illegal. Yup. » GroovyGreen.com

Is America Ready for the 'Smart Toilet?' For the kitchen and bath industry, the toilet is the final frontier.

Water. Too much, too little or just right?

An interesting conversation again is happening at Thom's Board from above link about family farms and that the present industrial farming system will collapse. Why?
Ren:

-- Sustainability.
It's a systems concept, which means it's not linear. Which means it fills up a blackboard in a hurry with circles filled with words, and arrows pointing to the circles and all sorts of mind scrambling visuals that don't fit into a Post A Reply window.

So instead of looking at every possible connection of how a system will collapse, I want to break it down to manageable components to discuss here. And of course one of the most important issue is water. This post is just going to look at some alternative ways to store/retain rain water.

The first link is to an "This Old House" special on This Roof Resists Hurricanes, Collects Water.

The thing about living in paradise is there's always a catch. In the case of Bermuda, where This Old House has been filming the renovation of a 200-year-old Georgian house, hurricanes hit the small mid-Atlantic island summer and fall, toppling trees, rattling shuttered windows, and peeling off roofs. Oh, and then there’s the absence of any fresh water source on the island. As a result, Bermuda’s roofs have evolved over four centuries to do two things: protect houses against gale-force winds and funnel whatever the heavens rain down into large cisterns that feed household taps. By law, every house must collect 80 percent of the water that falls on its roof.
...
The result is a strong, nearly self-supporting structure that holds its own against the weather while sending clean water into the tank. It’s the best and cheapest way to supply fresh water — up to 30 gallons per person are needed per day — to the 60,000-plus residents of this tiny island nation. It's also what accounts for Bermuda's signature white rooftops, perfectly placed amid the palms and set off by the pastel houses for which the island is famous.

Next is for another island (Key Westers) that has access to a supply of water but wants to save water and thus money to have it piped in, at Water Conservation Conch Style

For one, collected rainwater is ideal for irrigation--why pour potable water, at $5.20 per thousand gallons, out on the monkey palm? Some estimates claim irrigation accounts for nearly 40% of water use in Key West, so easing that load would leave a large proportion of the 14 million gallons of piped-in water the island uses each day back in the Everglades aquifer where it belongs.

Another benefit: Cisterns catch water that would otherwise become storm-water run-off--rain that falls, washes the island's building, streets and parking lots, and then needs a place to go. Currently, most of that greasy, dirty water ends up in the ocean, where it is implicated in killing off the living reef that surrounds the Keys.

But of course there will be some are always areas of concern...

Although many were destroyed as anachronistic and breeders of mosquitoes after the Navy's pipe came in, there are still 353 cisterns of record on the island. Old Henry Flagler, builder of the railway that linked Key West to the mainland, put a million-gallon one beneath his Casa Marina Hotel back in 1922, and it's still being used to water the grounds. Good enough for Conchs and capitalists, the cistern seems to be an old idea that's coming back.

The next link is a very useful guide for setting up cisterns/catchments at:1.1 Rainwater harvesting from rooftop catchments. I only want to add the concerns here at present.

· A procedure for eliminating the "foul flush" after a long dry spell deserves particular attention. The first part of each rainfall should be diverted from the storage tank since this is most likely to contain undesirable materials which have accumulated on the roof and other surfaces between rainfalls. Generally, water captured during the first 10 minutes of rainfall during an event of average intensity is unfit for drinking purposes. The quantity of water lost by diverting this runoff is usually about 14l/m2 of catchment area.
· The storage tank should be checked and cleaned periodically. All tanks need cleaning; their designs should allow for this. Cleaning procedures consist of thorough scrubbing of the inner walls and floors. Use of a chlorine solution is recommended for cleaning, followed by thorough rinsing.
· Care should be taken to keep rainfall collection surfaces covered, to reduce the likelihood of frogs, lizards, mosquitoes, and other pests using the cistern as a breeding ground. Residents may prefer to take care to prevent such problems rather than have to take corrective actions, such as treating or removing water, at a later time.
· Chlorination of the cisterns or storage tanks is necessary if the water is to be used for drinking and domestic uses. The Montserrat Island Water Authority constructed a non-conventional chlorination device with a rubber tube, plywood, a 1.2 m piece of PVC tubing, and a hose clip to chlorinate the water using chlorine tablets.
· Gutters and downpipes need to be periodically inspected and cleaned carefully. Periodic maintenance must also be carried out on any pumps used to lift water to selected areas in the house or building. More often than not, maintenance is done only when equipment breaks down.

Of course maitenance levels depends on what it will be used for as in if only irrigation then chlorine is likely to be overkill.

And now closer to home at Harvest the Rain.

Wrangle water from the sky for watering, washing and even drinking, no matter where you live.

Adapted from Environmental Building News

Rainwater harvesting systems can be as simple as directing gutters to a lidded garbage can or as complex as a concrete cistern, roof washer and filtration system. But whatever your application, rest assured that you'll be getting some of the purest - and cheapest - water around.
...
But after it falls from the sky, rainwater percolates through the earth and rocks, where it picks up minerals and salts. As Heinichen points out, in many cases, this water also collects other contaminants such as industrial chemicals, pesticides and fecal coliform bacteria found in the soil. Captured before it hits the ground, rainwater is free of many pollutants that plague surface and underground water supplies and, according to the Texas Water Development Board, "almost always exceeds [the quality] of ground or surface water."

Rainwater typically has very low hardness levels, which reduces the use of soaps and detergents, and eliminates the need for a water softener. Fewer minerals also saves wear and tear on your plumbing fixtures.

Now there can still be contaminants in the rain water but as far as acid rain, this should not be a problem for many people other than the east coast and most notably in the North East. On this map at National Water Conditions look for areas that have less than pH 5 as the article Acid Rain spells out.

More Links of Interest:
International Rainwater Catchment Systems Conferences
CISTERNS FOR KENTUCKY
Save Family Farms, Save America

Easy access to water causes baby boom/Better water supplies are linked to rise in hungry children in Ethiopia.

Improving access to clean water can cause unexpected health problems, suggests a study in Ethiopia.

Cutting down a woman's long trek to get water can boost her fertility. But bumping up birth rates worsens childhood malnutrition overall.

It is widely accepted that a cleaner water supply will enhance the health of those in developing countries. But few studies have tested how such installations affect a village as a whole.

Two UK researchers examined what happened after water taps were plumbed into several rural villages in southern Ethiopia between 1996 and 2000. They gathered information on children's births and deaths before and after the water supply arrived, and compared the data to that collected from settlements without a new tap.

I'm sorry but maybe this is not so bad, that women have more time and energy to help the family out.

Weighed down

As they expected, the taps slashed the death rate among children by half, at least partly because they cut infectious diseases spread in dirty water. More surprisingly, the pair found that women were, each month, three times more likely to give birth in the years after the tap was introduced. Mhairi Gibson of the University of Bristol and Ruth Mace of University College London, both in the UK, report their findings in Public Library of Science Medicine1.

The increase in birth rate did not seem to be explained by factors such as changes in the women's age, overall health or prosperity. The researchers suggest that the women's fertility may have soared because they had stopped burning up energy trekking to and from distant water supplies. The women had previously spent up to six hours per day fetching water in extremely heavy clay pots. "I could barely lift an empty one," Gibson says.

The women's fertility may have been partly dampened by this strenuous exercise, says Gibson, much as athletes often experience a drop in fertility from excessive training. When the women had to walk only 15 minutes to a village tap, their fertility shot up.

So maybe live births will increase but does this report mean we should not give water to these villages?

More mouths to feed

This boost in birth rate takes a toll on children's health. The investigators found that kids were more likely to be malnourished, based on their height and weight, in villages with taps than in those without.

This could be simply because families are sharing their scarce food between more children. Or perhaps low birth-weight babies, who previously would not have survived the trauma of birth, are now surviving but not thriving.

The higher birth rate might help explain why rural Africa's population continues to spiral upwards despite slowly improving living and health conditions, Gibson says. It contrasts with the rapid drop in birth rates seen in developed countries as economic conditions improve and family planning becomes more widely used.

Gibson says that aid agencies and other organizations that promote access to clean water may overlook the effects on birth rate.

She argues that new taps, or other development schemes, should ideally occur in parallel with increased access to contraception and child healthcare. "It's something these organizations haven't really looked at," Gibson says.

Yes we may expect a growing population in Africa, but is this so bad? And it will be expected to fall off if there is a sustained level of economic growth. The problems are not related to economic growth also. Africa has a whole host of problems that limit economic growth, ie Aides, Malaria, authoritarian regimes, war, and democide. It is no wonder that given a chance families plan to have more children.
And yes it would be nice to have the whole package together with contraception and a healthcare system, but only so much resources are available at any one time. It would be a shame if some organizations use this information to only help one group instead of trying to help a larger group. The cost of the wells are probably low compared to those other costs that need to be put into the package.