by Unknown
That’s enough about farts. Time to move on to some research that’s a bit more solid.
Engage dark matter!
‘I’m trying as hard as I can, Captain,’ exclaims Scotty, the strain etching lines in his forehead. ‘I can’t give you any more!’ But unlike Star Trek’s Enterprise, it was once hoped that spacecraft might use a less savoury energy supply than Scotty’s beloved dilithium crystals: human waste.
In 1999, NASA enlisted the aid of Advanced Fuel Research of Connecticut in a $600,000 project to turn astronaut waste—either faeces or some plastics—into a power source for spaceships using pyrolysis: the breaking down of waste by heating it in the absence of oxygen.
Normally, when organic molecules such as those found in faeces or in plastic are burned, they combine with oxygen in the air, producing carbon dioxide and water. But in pyrolysis, there is no oxygen to combine with, so the molecules break their bonds and rearrange themselves into smaller molecules. According to AFR scientist Mike Serio, ‘Things start breaking down at about 350 °C, and what you start making includes a lot of liquids. At 600 °C or 650 °C, you break down the liquids into gases. It does give you flexibility.’
You could burn these liquids or gases to release energy, or turn them into plastics or other organic materials. Pyrolysis could produce heavier molecules such as benzene or toluene, and could be a source of raw materials to make plastics or rubber. It could also create ammonia for fertiliser.
‘You can use human waste as well as other waste, like scrap plastic bags,’ said Jim Markham, AFR’s chief executive officer. And you wouldn’t have to worry about variations in the consistency and content of the waste material—the pyrolysis unit would be able to handle them all. ‘It’s tailored to unpredictable mixtures,’ he said. ‘Ideally, you’d dial in the desired outcome and it would compensate.’
Research into the usefulness of human waste products might be relatively new, but turds themselves have been with us for a long time. Long enough to become part of the fossil record. Apparently, the oldest terrestrial faeces discovered were found by researchers at the University of Wales in Cardiff. British academia leads the world once again. Believed to be from the earliest land-dwelling herbivores, the turds are 412 million years old. There’s probably not too much you can learn from them once they’ve turned into rock, but the same cannot be said about whale faeces.
Sniffing out whale poo
‘I hope we get a poop today,’ said Rosalind Rolland, a conservationist at the New England Aquarium, pouring her morning tea. ‘Just one.’
‘Maybe two,’ said her colleague Scott Kraus. ‘If you follow something long enough, it’ll poop.’
Their colleague Fargo, having dedicated over half his life to the subject, was even more enthusiastic. In 2006, Fargo was one of an elite corps of whale-scat sniffer dogs, and perhaps the most important member of the research team.
Whales may be the biggest creatures on the planet, but they also swim fast and dive deep, so are notoriously difficult to study. Fortunately, you can tell a lot about an animal by studying what it leaves behind. In faeces, researchers can find clues about an animal’s distribution, abundance, sex and reproductive status, stress levels, health and vitality.
Spotting scat samples, which hang just below the sea’s surface before they break apart, is far more difficult than finding the animals themselves, and that’s where dogs like Fargo come in. With years of training and more than 200 million olfactory receptors—compared with humans’ mere 5 million—dogs can ramp up the number of samples.
Upwind of a few whales, Fargo dropped his snout. ‘He’s got scent’ said Rolland. Fargo paced back and forth across the bow but then stopped moving. He had lost the scent. ‘It might have been a big fart,’ Rolland conceded.
Rolland figured that faecal sampling would help her narrow down why right whales had stopped reproducing in the North Atlantic in the late 1990s. She thought faecal samples could be used to test reproductive hormones, as had been done in primates and other animals. They began with just humans searching for whale poo, but when dogs were introduced samples increased fourfold. On average, dogs collected about a scat an hour—a rate Rolland referred to as ‘poops per unit effort’.
Whale faeces are surprisingly modest, the size of a small brick and a reddish brown. When the team finally located one, research assistant Cindy Browning scooped it up with a fine-meshed plankton net. Rolland and Browning carefully stored the sample in palm-sized plastic jars. Once it was brought on board, the smell was overwhelming. ‘If you spill it on your clothes,’ Rolland warned, ‘you want to throw those clothes away.’
In 2006, the samples were proving invaluable. Rolland and her colleagues showed that paralytic shellfish poisoning, caused by eating shellfish contaminated with toxic algae, may have contributed to the right whale’s failure to recover from centuries of hunting. Perhaps even more troubling was the presence of domoic acid in right whales. This toxin has several neurological effects, including seizures and coma, and had been responsible for the death of hundreds of sea lions in the Pacific. Protozoan parasites could also have caused problems. These had been associated with diarrhoeal disease in land mammals, and it was thought that the blame might have lain with humans. Right whales spend much of their lives close to big cities. They might have been picking up these parasites from human or domestic animal waste dumped in the ocean.
Hormone studies, by contrast, brought some good news. By looking at levels of progestogens and oestrogens, researchers were able to estimate the reproductive status of females, and many were doing well. The study had also been expanded to study killer whales, whose faeces, for the record, are a snotty greenish brown. They are also less buoyant than right whale scat and difficult to spot from a boat. Once back in New England, Rolland reflected on the work still to be done to protect the whales. ‘I thought I’d be into something else now,’ she said, ‘But I’ve just gotten deeper into it.’
With so much poo about, you’d be forgiven for thinking there would be no entrepreneurial benefit in manufacturing extra. You’d be wrong.
Faking it
In 1994, Richard Yeo and Debra Welchel of the Kimberley-Clark Corporation in Dallas, Texas, invented a recipe to simulate something you might have thought was fairly abundant in America: human faeces. Their mix consisted of polyvinyls, starches, natural gums and gelatins, all water-soluble, plus insoluble fibres and resins. Add water to this and you would get a synthetic turd ‘as close to the real thing as possible’, Yeo told the New York Times.
This is impressive, but by now a question may well have occurred to you: why would we need it? The answer was that Kimberley-Clark makes nappies and adult incontinence pads and these products must be rigorously tested. ‘But the technicians have some objection to handling the real thing,’ Yeo said, adding that actual faeces are ‘a form of biologically hazardous material’.
In addition, the firm’s labs might have found they needed, say, 10 kilograms of faeces at 9 o’clock on a Monday morning, to begin tests on a new range of nappies. The real thing, Yeo complained, can be ‘a bit difficult to obtain, even from infants’.
Any scientific endeavour typically starts with a review of the existing literature. ‘We had fundamental studies of real faeces,’ Yeo said, ‘so we knew what was needed.’ Previous attempts to make do with peanut butter or pumpkin pie mix had failed—their liquids and solids separated too rapidly.
The material mimicked faecal behaviour far more accurately, in all but one respect: it had no odour.
Of course, fake poo is only half the story. Some people are making fake urine too. Just what is it about Texans and phoney human waste?
Just add water
In 1986 in Austin, Texas, entrepreneur Jeff Nightbyrd marketed instant urine for the growing number of employees being asked by their bosses to undergo tests to see if they were using drugs.
Like instant coffee, the urine came in powder form, and was reconstituted by adding hot distilled water. It
could be ordered by mail at a cost of $19.95 for 2-gram vials, providing enough urine for two samples. Nightbyrd never said how he turned urine into powder, but it must have been a very smelly business.
And from faking it, to reusing it. ‘Waste not, want not’ is a maxim held in high regard by interstellar travellers. In space, no one can hear you pee…
Purified urine to be astronauts’ drinking water
In 2008, as NASA prepared to double the number of astronauts living aboard the International Space Station, nothing was expected to do more for crew bonding than a machine being launched aboard the space shuttle Endeavour: a water-recycling device designed to process the crew’s urine for communal consumption.
‘We did blind taste tests of the water,’ said NASA’s Bob Bagdigian, the system’s lead engineer. ‘Nobody had any strong objections. Other than a faint taste of iodine, it is just as refreshing as any other kind of water. I’ve got some in my fridge,’ he added. ‘It tastes fine to me.’
Delivery of the $250 million wastewater recycling gear was among the primary goals of NASA’s 124th shuttle mission, which launched from the Kennedy Space Center in Florida in November 2008. In addition to the water recycler, the shuttle Endeavour also carried a second toilet.
‘With six people, you really do need to have a two-bathroom house. It’s a lot more convenient and a lot more efficient,’ said Endeavour astronaut Sandra Magnus. Reusing water will become essential once NASA retires its space shuttles, which produce water as a by-product of their electrical systems. Rather than dumping the water overboard, NASA has been transferring it to the space station.
But the shuttle’s days are numbered. NASA is preparing to end the programme in 2010, after which Russian Soyuz spacecraft will be the only way to ferry crew to the space station. ‘We can’t be delivering water all the time for six crew,’ said space station flight director Ron Spencer. ‘Recycling is a must.’
NASA expected to process about 6 gallons (23 litres) of water per day with the new device. The goal was to recover about 92 per cent of the water from the crew’s urine and moisture in the air. The wastewater was processed using an extensive series of purification techniques, including distillation—which is somewhat tricky in microgravity—filtration, oxidation, and ionisation. The final step was the addition of iodine to control microbial growth. The device was intended to process a full day’s worth of wastewater in less than 24 hours. ‘Today’s drinking water was yesterday’s waste,’ Bagdigian said.
The first recycled astronaut urine came on stream in the International Space Station in May 2009. Apparently it tastes ‘great’. But while urine can seemingly be used again and again, it appears that dirty underwear is not for sharing.
Less waste, more space
One of space travel’s most pressing but least-known problems is what to do with dirty underwear. One solution, attempted by Russian scientists in 1998, was to design a cocktail of bacteria to digest astronauts’ cotton and paper underpants. They had hoped that the resulting methane gas could be used to power spacecraft.
The disposal unit would be able to process plastic, cellulose and other organic waste aboard a spacecraft. Cosmonauts identified waste as one of the most acute problems they face. Each astronaut produces an average of 2.5 kilograms of uncompressed waste a day. To keep waste to a minimum, they are forced to wear underwear for up to a week, and discarded undergarments are burned up in the Earth’s atmosphere in waste modules that call twice a year.
The researchers aimed to complete their microbial disposal unit by 2017 to coincide with Russia’s planned launch of a ere wed interplanetary mission to Mars.
It’s either that, or the cosmonauts pay a visit to Alex Fowler. If they did, they might be able to wear their smalls indefinitely…
No more laundry
Most of us try to wash bacteria out of our clothes. Not so Alex Fowler, who wanted several thousand bugs to set up home inside every single fibre of a fabric, living, breeding and eating up the dirt. Welcome to the world of self-cleaning clothes.
Eventually, the garments in your wardrobe may be able to support a variety of bacteria engineered to eat odour-causing chemicals and human sweat. Other bacteria might secrete waterproof and protective coatings to extend the life of clothing and produce antiseptic for bandages. Ironically, textile makers have spent millions developing fibres blended with, say, silver ions or chlorine to kill off the bugs in fabric.
But encouraging bacteria to grow on fibres turned out to be harder than Fowler had expected. ‘I thought they would wick into the fibre by capillary action, but it didn’t turn out like that,’ he said. Brute force was required. In 2001, Fowler and his team from the University of Massachusetts at Dartmouth developed a vacuum pump that could connect to the end of hollow fibres from the milkweed plant. Although no longer used to make clothes, the plant is still used to make rope.
The pump sucked a few drops of agar jelly containing Escherichia coli into the fibre. The bacteria easily formed a thriving colony and began to breed. After some initial tests, Fowler had no problem firing several hundred bacteria into the fibre. ‘They’re tough little guys,’ he said. Fowler used a harmless strain of E. coli genetically engineered to produce a fluorescent protein from a jellyfish to make the bacterium glow as it grew, allowing researchers to monitor its progress.
The group weren’t sure how long the bacteria could survive in the fibres. They suspected they might become dormant after several weeks when their food supply ran out, but Fowler hoped to reactivate them by soaking the milkweed fibres in additional nutrients. So if your shirt was impregnated with a strain of E. coli designed to feed on human sweat and the proteins that cause body odours, you’d only have to wear it to jolt the bugs into action. For some other strains, you might have to douse it with additional nutrients occasionally. ‘You could end up having to feed your shirt instead of wash it,’ said Fowler.
All this orbital recycling of urine and bacterial underwear destruction raises a question though. In zero gravity, just how do you emit all the waste?
Wind in the loo
From the outside, the 1972 space shuttle toilet looked much like the uncomfortable apparatus found in the jet airliners of the era. Inside, however, liquid and solid wastes were directed into separate pipes by high-velocity air streams that compensated for the lack of gravity on board the shuttle. The waste was held in two tanks—solids being vacuum-dried, sterilised and deodorised, ready to be pumped out when the shuttle returned to Earth. Depositing them in orbit would have obscured rearward vision and possibly interfered with external equipment.
Very clever, but not as ingenious as Göran Emil Lagström’s multipurpose device…
Hot seat cleans up
Most of the best inventions kill at least two birds with one stone. Göran Emil Lagström’s 1972 invention both disposed of lavatory waste where there was no proper sewage system and provided central heating. The contraption consisted of a combustion chamber with an oil or gas burner to burn solid waste and evaporate liquid waste, all situated under the toilet pan and surrounded by a water jacket. The jacket was connected to a large column-like tank which fed a central heating system.
Inside the tank, and heated by it, was a second, completely separate water-heating system which provided hot water for washing. The water was supplied from the mains or a water store.
The hot exhaust fumes from the burning waste were passed from the combustion chamber to a chimney.
Lovely. But enough about toilets. Time to move on to snot, bad breath and mouldy food. In 2002, New Scientist ran this article about the mysteries behind the runny nose.
Season’s sniffles
SCHNIFFFRRPGHRRT…Ah, that’s better. Uh oh, unbecoming drip is rapidly re-forming on end of nose. Hunt frantically through pockets for bedraggled scraps of paper hanky. No joy…oh well, only one thing for it. Time to deploy the sleeve.
Admit it, you’ve been there. You are fabulously dressed to impress, ready to mingle, frolic, see an
d be seen. After a 20-minute walk in the freezing cold, you arrive triumphant. Then, as your body warms up and you begin an intelligent conversation with your boss, your nose begins to drip like a leaky faucet. The phenomenon has earned an entry in medical textbooks as ‘cold-induced rhinitis’. But don’t be fooled by the fancy name. The truth is that no one knows very much about it, although scientists have pointed the finger at the autonomic nervous system, which directs involuntary actions such as breathing. Nerves belonging to the autonomic nervous system, some of which connect to the nasal glands, use a neurotransmitter known as acetylcholine. Fortunately, there is a quick fix. Ipratropium bromide is an inhibitor of acetylcholine. Two squirts of the solution in each nostril 45 minutes before skiing, snowballing or eating spicy food and the problem is taken care of.
Most people go through life unaware how easy it is to fix the problem. According to William Silvers, an allergist from Vail, Colorado, whose fascination with runny noses won him recognition as ‘The Skier’s Nose Doctor’, people don’t do much about their sudden bouts of sniffling because they are simply not seen as a medical issue. In fact, Silvers claimed, when faced with the grim realisation that their nose has begun to leak, the majority of folks take the matter into their own hands—quite literally. ‘That’s why they make cycling gloves with absorbent terry cloth on the outside,’ he said. You thought they were designed to mop sweat? ‘Well, I use them for my nose,’ he replied, unabashed.
