From CSIRO ‘Science by email’
Mopping up with food scraps
Do you have left over fruit and vegetable scraps? One day you might be able to use them to clean up the environment!
While we won’t be using lettuce leaves and potato peel to mop up oil spills any time soon, scientists in India have used waste from onion and garlic canning to remove pollutants from wastewater.The pollutants in question are heavy metal ions, such as lead, cadmium and mercury. These ions are highly toxic to both humans and wildlife, so their presence in the environment is bad news.
Using biological material known as ‘biomass’ from the onion and garlic, scientists tested to see if heavy metal ions could be removed from industrial wastewater. The researchers changed a few variables, including pH (acidity), temperature and pollutant concentration, to determine the best conditions for removing pollutants.
For example, the scientists found that for a particular concentration of heavy metal ions at a temperature of 50°C and pH of 5, more than 70% of the lead ions could be removed from the water and recovered from the biomass using nitric acid. The biomass could then be reused to remove more heavy metal ions. This could hopefully lead to better methods of reducing heavy metal pollution.
This experiment indicates how important it is for scientists to consider all possible variables when doing their research. In order to get a clearer picture of what is going on, scientists will often repeat experiments with slight variations in conditions and compare the results.
Cleaning up pollution is hard work. Traditional methods such as physically removing polluted soil are very expensive and may not completely solve the problem. Using waste biomass is appealing because it is cheaper and in some cases may be more effective at removing the pollution.
If you like your hot water brimming with history there’s nothing quite like Bath, England. Bubbling up through gravel along the bed of the River Avon, water emerges at 46 degrees Celsius. The water has been captured in constructed pools for bathing since Roman times.Water surfacing today last saw the light of day thousands of years ago when it fell as rain. It’s difficult to follow its long journey, but geologists believe the rain slowly wove its way through fractures in the rock to a depth of about two kilometres. Here, hot rocks heated the water and pressure pushed it back to the surface.
As well as providing a muscle-soothing soak, hot rocks deep in the Earth are a potential source of energy. Groups around the world are researching areas where hot rocks are closer to the surface. If a site doesn’t already contain hot water, they can drill a hole to hot rocks and add their own water supply. Either way, they could use the natural heat to turn water to steam for powering turbines and producing electricity.
This is already being done in Birdsville, Queensland, where Australia’s only geothermal power station can be found on the edge of the Simpson Desert. A bore more than a kilometre deep draws up water naturally heated to almost boiling point. The water is used to heat another fluid called isopentane, which has a lower boiling point. The isopentane turns into gas and rotates an alternator to make electricity.
If you want to take in the waters in a more relaxing fashion, you don’t have to be in Rome to do as the Romans do. There are plenty of hot springs around Australia – maybe you could find one in your area.
Recent interviews with cyclist Lance Armstrong made headlines around the world. He admitted to the use of performance-enhancing drugs to win the Tour de France. Scientists have overcome many hurdles to develop the drug testing that underpins this revelation.
Among other things, Lance admitted to using recombinant human erythropoietin (rEPO) during his cycling career. Erythropoietin (EPO) is a hormone produced naturally by the kidneys, and is responsible for red blood cell production. Red blood cells carry oxygen around the body. Having more red blood cells increases an athlete’s endurance.Everyone has some EPO in their body, so detecting rEPO abuse by athletes is not easy. rEPO that has been injected is almost identical to EPO that naturally occurs in the body. To test for rEPO, an athlete is required to give a urine sample. Roughly a tablespoon of urine is concentrated down to about one drop. The sample will contain EPO, rEPO (if the athlete has been using it) and other proteins.
The sample is placed on a gel, and an electric current run through it. The electricity causes the large protein molecules to separate and spread out. Like a cloth absorbing a spill, a membrane is then used to blot the gel. The membrane contains antibodies that bond to proteins. After a second blotting, just rEPO and EPO molecules will stick to the membrane.
The membrane is then treated with other chemicals. If rEPO is present on the membrane, this treatment will cause it give off light in a particular pattern, where it is detected and measured. For an athlete to test positive to rEPO, additional confirmation tests are undertaken and another of their samples (a B sample) can be tested to confirm the initial results.
Since the introduction of a test for rEPO, its use appears to have dropped significantly. Anti-doping officials are now concerned about the use of blood transfusions, where blood is removed from an athlete, stored and then reinjected later in order to give a performance boost. This is even harder to detect than EPO because it is the athlete’s own blood that is the performance-enhancing substance.
The Lance Armstrong case shows how important science continues to be in monitoring drug use in sport.
King Richard III Grave
The graves of kings and emperors: pyramids in Egypt, terracotta armies in China and … a car park in England? A team from the University of Leicester announced they discovered the remains of King Richard III under a council car park.
Typically kings are given a royal burial, but Richard III was the defeated leader in a civil war, so this honour was denied. It was unknown where he was buried after his death in 1485.Accounts stated that his body was buried in a local church. The church was long gone, but a group of archeologists reasoned that, if they could locate the church, they might be able to find Richard.
Using old maps, they picked locations where they thought the old church might have been – including a car park. They dug three trenches in the car park, and discovered not only the foundations of the church, but also a skeleton. The skeleton was quickly and carefully removed.
The location of the male skeleton was as expected according to legend. Physical features including the slight build and curved spine matched descriptions of Richard. The skeleton also showed evidence of a number of wounds consistent with accounts of injuries inflicted in battle and after death. The pieces were falling into place.
The team also successfully extracted DNA from a tooth. They were interested in a type of DNA called mitochondrial DNA (mtDNA). Mitochondria are structures in cells that convert energy from food into a form that cells can use. They have their own DNA: mtDNA.
You get mtDNA from your mum. A mother will pass her mtDNA onto her daughter, who will pass it on to her daughter and so on. Sons also get their mtDNA from their mother, but if they father children, it will not be passed on.
If the remains belonged to Richard, the mtDNA extracted should match the mtDNA from a descendant of Richard’s mother – as long as there were only women in the line of descent. It just so happened they had two such descendents! The mtDNA from the three samples were compared – they all matched. However, it’s still possible that people can have the same mtDNA by chance.
None of these pieces of evidence are enough by themselves, but pieced together with further information, the team is convinced they found the remains of King Richard III.
Science can clearly help improve people’s lives. Yet in an ever changing society, finding efficient ways to help the most people can be challenging.
Research organisations such as CSIRO provide answers to a wide variety of questions. However, to make a real difference in people’s lives, researchers need to work with non-scientific groups who connect with different parts of the community.The Australian Government’s Department of Human Services is responsible for more than 200 services that help people who are sick, disadvantaged, or just down on their luck. The Department delivers Centrelink, Medicare and Child Support payments and services, including family assistance.
Society is complex, filled with people that have different needs, skills and values. To understand something as complicated as the Australian population, the Department of Human Services has formed an alliance with CSIRO called the Human Services Delivery Research Alliance (HSDRA). This alliance was created with the aim to find better ways to model and evaluate social welfare and ultimately improve service delivery.
One of the projects under the alliance is exploring how to efficiently use social media as a communication tool to evaluate and organise services based on different individual needs, and how to better research the impact of the delivery of social services.
For science to help communities, it requires more than just models and mathematical equations. It requires working closely with those who understand the problems in need of a solution.