This week, I want to do a round-up of stories that - for one reason or another - I skipped the first time around.
A few weeks ago, I was talking about an unbelievably simple device for removing arsenic from drinking water. Now, it looks as though there might be an even simpler solution, which would have the added benefit of destroying an invasive plant!
Parvez Haris and his team at De Montfort University in Leicester suggest that dried and powdered root from water hyacinth, an invasive species from South America that is wreaking havoc across Asia and Africa, could be used to filter out arsenic....Lab experiments show that adding the root powder to contaminated water reduces arsenic levels to below the World Health Organization's safe limit of 10 micrograms per litre, even from initial concentrations 20 times as high.In a somewhat related development, it's been proven that India's traditional brass water-pots kill bacteria that cause food poisoning:
After hearing anecdotal reports that water stored in mutkas is safer, Rob Reed and Puja Tandon at Northumbria University in Newcastle upon Tyne, UK, decided to investigate. When they added E. coli to water in various containers, the bacteria were all dead within 48 hours in mutkas, but survived in earthenware or plastic containers.The bacteriocidal mechanism turns out to be copper leaching into the water, at levels far below the recommended daily dose for humans.
Whenever I talk about stories like these, I'm struck by the huge difference between what I need in order to have a better life, and what most of the world needs. For me, positive change means huge, tumultuous things: government figures languishing in jail, media figures in pillories, a complete revolution in public thinking, and other idle daydreams. But in many countries, of course, "positive change" means getting access to simple amenities like clean water.
And in others, it means being able to walk through a field without getting a leg blown off. I'm happy to report that there's a simple and inexpensive new aid to achieving this exceedingly humble desideratum:
British experts have teamed up to design a new anti-landmine device - called Dragon - to deal with millions of hidden explosive devices.The Dragon is safer and less environmentally destructive than purposefully detonating the mines. Another thing I like about it is that its inventors have taken local needs and capabilities into account:
The device has been built by disarmament specialists Disarmco with the help of arms experts at Cranfield University in Bedfordshire. The high-temperature flare burns mines without causing them to explode.
Professor Ian Wallace, Head of Cranfield University's Department of Environmental and Ordnance Systems, said: "Working with the Disarmco team, we've created a new formulation based on low cost materials which are readily available around the world. Local communities - with little training - can use the portable production unit to manufacture the thousands of Dragons required to deal with landmines and un-exploded ordnance (UXOs)."You can read more about Disarmco's work here. And if you're American, you can remind yourself that our "Culture of Life" crowd has consistently refused to do anything about land mines, which kill 8,000 and maim 20,000 innocent people per year; and that our cowardly, complicit media refused to air a commercial that dramatically demostrates what land mines do to children every day. Having contemplated this for even a nanosecond or two, you may feel inclined to give the Mines Advisory Group some money.
Another small thing that can make a big difference to besieged communities is urban food gardens. Bitter Greens Journal - a site I recently discovered and am already addicted to - discusses the value of these projects:
The trick is to create agricultural systems within and just outside of cities, minimizing the ruinous effects of long-haul freight transit, maximizing availability of fresh delicious food, and boosting local and even neighborhood economies.BGJ goes on to describe a remarkable inner-city gardening project in Detroit. These gardens are catching on in African-American neighborhoods in many U.S. cities, and they're really wonderful. They teach a skill; they demonstrate scientific principles; they provide fresh vegetables to a community whose consumption of greens is well below the national average; they provide a source of income for impoverished neighborhoods; they beautify derelict areas, and attract songbirds, honeybees, and butterflies...it's hard to say enough good things about them, but H. Patricia Hynes' A Patch of Eden: America's Inner City Gardens tries heroically.
So much for local, low-tech issues. The big news on the high-tech front (in my opinion) is the increasing commercial feasibility of the vanadium redox battery (VRB); Treehugger did a story about it on April Fool's Day, leading some people to believe that it was a cruel hoax. Fortunately, it wasn't:
A new mass energy storage technology is on the cusp of entering mainstream society. The Japanese are currently using it on a grand scale, the Canadians have comprehensively evaluated it and soon Australians will have the opportunity to replace their old lead-acid batteries with a Vanadium Redox Battery alternative. There are no emissions, no disposal issues, no loss of charge, the construction materials are 'green' and the battery can be charged and discharged simultaneously.The really fascinating thing about the VRB is that it can be recharged by, say, solar or wind power...but it can also be recharged by refueling:
Refuelling in five minutes by exchange of electrolyte at a specialised refuelling station allows 24 hour operation of buses, taxis, fork-lift trucks and other vehicles (not possible with any other type of battery system)....Unlike petrol, however, the vanadium solutions are never consumed, but can be recharged indefinitely. The spent solutions could thus be stored at the refuelling stations for recharging at night with off-peak electricity. The VRB recharging stations would thereby act as load-levelling systems, so that the need to build extra power stations to meet the increased power demand from electric vehicle charging would be deferred.A small VRB can't yet power a conventional passenger vehicle, but the possibilities are heartening. And if the developer's site is to be believed, China is negotiating for a fleet of VRB buses - with electrolyte replacement and recharging stations - for use during the 2008 Olympics.
In other battery news, Alternative Energy Blog notes that Toshiba has developed a new lithium-ion battery that can be recharged to 80% of capacity in one minute:
The battery has a long life cycle, losing only 1% of capacity after 1,000 cycles of discharging and recharging, and can operate at very low temperatures.
Toshiba will bring the new rechargeable battery to commercial products in 2006. Initial applications will be in the automotive and industrial sectors, where the slim, small-sized battery will deliver large amounts of energy while requiring only a minute to recharge.