Posts

,

Chemists Develop Solution to Water Crisis

water_crisis
If you think back to your days as a kindergartner, you may remember the first time you learned the water cycle. Equipped with a blue crayon, you replicated what your teacher described in a simple picture: rain falls, people drink it, the water evaporates and the whole thing repeats. You learned that water is renewable.

But renewable does not mean unlimited, a fact constantly recognized by the 780 million people who lack access to clean drinking water.

Freshwater, the largest source of our drinking water, makes up only 2.5 percent of the planet’s water. Only 1 percent of freshwater is actually available, as most of it is frozen. This leaves 0.007 percent of the Earth’s water left for an ever-growing population that exceeds 7 billion. This is a water crisis.

“Why can’t we use ocean water?” one might ask. The answer is, well, we can.

Desalination, the removal of salt from saltwater, makes the use of ocean water possible. But breaking the strong bonds that salt forms with water molecules requires a lot of energy, and this energy is expensive.

As Peter Gleick, president of the environmental think-tank Pacific Institute, says, “It can cost from just under $1 to well over $2 to produce one cubic meter (264 gallons) of desalted water from the ocean.”

Considering that 99 percent of water-related illnesses occur in developing countries, desalination is simply an unrealistic option for most who suffer from the water crisis.

But what if there were some way to desalinate without such steep energy requirements?

A team of scientists believe they know how to do so.

Martin Bazant and Daosheng Deng of the Massachusetts Institute of Technology (MIT) have developed a process that they believe will more efficiently and effectively desalinate water. They call it “shock electrodialysis.”

Today, the two cheapest methods of desalination are reverse osmosis and electrodialysis.

Reverse osmosis works by pumping water through a membrane that does not allow salts to pass. Although it requires less energy than older methods, it works too slowly.

Building on reverse osmosis, electrodialysis tried the opposite: pumping salts through an electrified membrane until only pure water is left. This process is significantly cheaper than reverse osmosis but is not without shortcomings. It fails to decontaminate water of dirt and bacteria without additional filtration methods.

Bazant and Deng say that shock electrodialysis can produce clean, bacteria-free drinking water in one step. How? They placed an additional filter made of porous glass near the electrified membrane. Based on Bazant and Deng’s observations, dirt particles and bacteria are unable to fit through the tiny pores in the glass material.

If it turns out that this MIT development can be produced at a low cost on a large scale, shock electrodialysis could provide millions of people with access to drinking water.

– Shehrose Mian

Sources: UNICEF, National Geographic, Scientific American, Technology Review
Photo: Technology Review

,

MIT Researchers Find the Viral Gene in Microfinance

Viral_MIT_Microfinance
The central problem of many anti-poverty efforts is a failure to actually reach the poor. Often, the programs themselves are faulty or broken. Much of the time, however, the problem is demand-side: The poor don’t trust the aid programs and don’t want to participate.

Two MIT researchers think they have found a solution, however. Esther Duflo and Abhijit Banerjee, co-founders of the Jameel Poverty Action Lab (J-PAL), decided to measure an oft-overlooked factor in community development: social influence, or what they call “diffusion centrality.” Using their new metrics, they think they have found a key to motivating demand-side participation in charitable efforts.

In their recent paper, “The Diffusion of Microfinance,” they argue that finding the right “social injection points” is key to successful beneficial programs. They studied microfinance programs in 75 villages in southwestern India for five years, conducting extensive surveys to determine how participation in microfinance flowed along social networks. They paid especially close attention to social pressure points like village leaders, teachers, and business owners. What they found surprised them.

Although some of the typically well-connected socialites were excellent vehicles for transmitting participation in the programs, they were not as good as you would think. Many ranked low on their diffusion centrality index. Even people’s friends—the quintessential source of social pressure—had little effect on participation.

What they did find is that, barring any presumptions about connectedness, individuals who ranked in the 90th percentile of diffusion centrality were the gatekeepers to large-scale participation. When they were the first ones targeted by microfinance efforts, the programs ultimately reached 11% more people—from their perspective, a huge jump in participation.

“I think this work will lead to more innovative research on how social networks can be used more effectively in promoting poverty alleviation programs in poor countries,” says Lori Beaman, a professor of economics at Northwestern University and a J-PAL affiliate. “It significantly moves forward our understanding of how social networks influence people’s decision-making.”

– John Mahon

Sources: MIT, Stanford, New Yorker
Photo: MIT

Liter of Light

Liter-of-Light

Fiat lux! Let there be light! A timeless phrase that has been used since biblical times, in classrooms and even in movies has a more humanitarian and sustainable meaning since 2011. MyShelter Foundation, a ‘green-energy for all’ organization, began the Liter of Light project out of a simple idea to light up the homes of those who could not afford to do so themselves. With the help of MIT students, the technology of empty water bottles, water, bleach, and a slab of cement has taken the place of electricity and changed the lives of hundreds of thousands of people around the world.

The first installments began in Manila, Philippines. Since electricity rates are so high, families are forced to keep the lights off during the day. Due to the infrastructure of the homes in many of the poorer areas, however, light does not enter the homes during the day and families are left in darkness.

Building the makeshift light bulbs is easy and requires little to no maintenance. 1 liter plastic bottles are taken, filled with a small amount of bleach to keep the water and bottle clean and free of germs, then filled with water. When sunlight enters the bottle, enough light is produced that equals that of a 55-watt light bulb! The benefits of the water bottle bulbs are endless. Not only do they eliminate the need for electricity during the day, but they also reduce monthly electricity costs, are sustainable, help keep slums free of plastic waste, are easy to install, and add a greater sense of well being to the home environment.

Since 2011, Isang Litrong Liwanag (the translation of Liter of Light in Filipino) has spread to other countries such as Cambodia, India, Vietnam, Spain, Egypt, Peru, Kenya, the Middle East, and even Switzerland. MyShelter hopes to reach its goal of installing 1 million water bottle light bulbs by 2015.

– Deena Dulgerian

Source: A Liter of Light

Solar Panel Leaf Could Power the Developing World

leaf
Harvard University Professor Daniel Nocera has finally perfected the solar panel leaf that he began trying to construct several years ago at MIT. This new technology harvests solar energy in a unique way and has become a more practical way for people living in harsh conditions to gain access to electricity.

Nocera’s invention addresses the main problems with solar panels which are their high price, complexity and inability to produce power at any time. This leaves normal solar panels impractical for the developing world in many ways.

Nocera’s invention differs from a normal solar panel in that it breaks down solar energy similarly to how a plant photosynthesizes. In fact, the solar panel is touted to be ten times more efficient than the average leaf. Nocera’s artificial leaf breaks down solar energy into hydrogen and oxygen. The hydrogen is then held in a fuel cell and can be used on demand. Due to film build up, the initial design called for purified water to be used, which is rare in developing countries and rendered the invention impractical for impoverished communities.

However, Norcera recently developed a fix for this seemingly impossible problem. The innovators created a mechanism in the leaf in which a catalyst driving the chemical reaction breaks down. This provides a surface that is inhospitable for the film to develop.

With this new development, Nocera predicts that his invention will be widely used in developing nations as a cheap and sustainable way to create useable electricity.

– Pete Grapentien

Source: Knovel
Photo: Wired

Let there be Light: Solar Bottle Bulbs Illuminate Filipino Cities

Let there be Light: Solar Bottle Bulbs Illuminate Filipino Cities

When a group of imaginative students at Massachusetts Institute of Technology (MIT) first designed an experiment to make light emanate from plastic water bottles, they never imagined that their minimalistic idea would literally and metaphorically light up the lives of over 15,000 people.

The idea seems deceivingly simple: take an empty one liter plastic bottle, fill it with purified water and a few drops of bleach for cleanliness, and cement it halfway through a small metal roof sheet. The plastic refracts sunlight and suddenly illuminates every corner of a dark room.

But while its physics is straightforward, its impacts have been far greater than any of the original designers could have imagined. Many slum homes in developing nations lack proper lighting because of how closely they are constructed in relation to one another, and the families often cannot afford the luxury of electricity. Over three million families live immersed in darkness in metropolitan Manila, a Filipino city where the bottle of captured light has made the greatest difference.

Filipino student Illac Diaz, the creator of the My Shelter Foundation, has made it his personal mission to brighten one million homes in the Philippines by utilizing this elementary yet ingenious invention. He calls his project Isang Litrong Liwanag – A Liter of Light. Today, with the help of various organizations and individual volunteers, Diaz and his solar bottle bulbs have lit up over 15,000 homes in over 20 Philippine cities.

Although it is not a perfect technology because it does not produce light during the nighttime hours, it is surprisingly effective in the sense that it uses inexpensive and locally available materials to illuminate homes that had never experienced the luxury of light before. The MIT students’ science along with Diaz’s motivation have extended this project’s impact beyond providing light.

The success of A Liter of Light is a great model of a sustainable solution for a variety of socio-economic problems worldwide. It is an idea of Appropriate Technologies, a concept that provides a simple, replicable technology that fulfills the needs of developing nations by utilizing the limited resources they have access to.

And the Philippines aren’t the only country. From the jungles of Uganda to riverbanks of Bangladesh, these solar bottle bulbs are continuing to make their mark on countries all over the world. And for those families that now have these makeshift light bulbs in their homes, something that spreads a stray ray into the darkest interior can be much more than a bright idea.

To find out more, visit aliteroflight.org.

– Angie Lou

Source: Let’s Talk Magazine

MIT Offers Online Courses in Civil and Environmental Engineering

Engineering-MIT

More than seven billion people are packed into the world, with consumption and pollution increasing drastically every year. How can needs for water, sanitation, nutrition and health be met?

Engineering. New ways to provide energy, food, water, transportation, water disposal, health care, environmental clean-up, telecommunication and infrastructure must be created by engineers. Now, MIT offers an online course in Civil and Environmental engineering so more people have access to an engineering education and solution.

MIT’s department of civil and environmental engineering (CEE) teaches students how to create long-term infrastructure without harming the environment. CEE focuses on six main areas of research: smarter cities, ecosystems, coastal zone, water and energy resources, chemicals in the environment, and materials.

The undergraduate core curriculum examines the principles of earth systems and sustainability, fundamentals of solid and fluid dynamics, and incorporates labs that teach students how to plan, design and construct projects.

At the graduate level, CEE runs the two engineering programs, Engineering and Science in Transportation. These programs train engineers to create infrastructure and transportation systems that are environmentally friendly for companies and governmental agencies.

MIT offers 107 online courses in civil and environmental engineering; 34 courses are for undergraduate students and 73 are for graduate students.

– Kasey Beduhn

Sources: MIT, NAE
Photo: EWB MIT