Sunday, April 23, 2017

Graphene: The Secret To Low Energy Desalination?

Given that current desalination technologies cost millions of dollars and huge energy input to run it, will the newfangled graphene-based desalination devices drastically cut costs and energy consumption? 

By: Ringo Bones

According to the United Nations, it is expected by the year 2025 14-percent of the world’s population will encounter water scarcity. Given that the current “most energy efficient” way to desalinate water – i.e. reverse osmosis desalination plants – still costs hundreds of millions of dollars to build and their energy requirements is beyond that of a remote small town in sub-Saharan Africa to generate. Fortunately, a new wonder material, like graphene, could drastically slash the energy and cost requirements to build a desalination plant big enough to provide potable water to a typical out of the way small town. 

Graphene-oxide membranes have attracted considerable attention as promising candidates for new filtration technologies, especially ones that are less expensive and require lower energy to operate than existing ones. Now the much sought-after development of making membranes capable of sieving common salts has been achieved. New research demonstrates the real-world potential of providing clean drinking water for millions of people who struggle to access adequate clean water sources. 

When common salts are dissolved in water, they always form a “shell” of water molecules around the salt’s molecular structure. This allows the tiny capillaries of the graphene-oxide membranes to block the salt from flowing along with the water. Water molecules are able to pass through the membrane barrier and flow anomalously fast which is ideal for application of these membranes for desalination. 

Professor Rahul Nair at the University of Manchester said “Realisation of scalable membranes with uniform pore size down to atomic scale is a significant step forward and will open new possibilities for improving the efficiency of desalination technology”. Prof. Nair’s experimental desalination device at the National Graphene Institute of Manchester uses a one-atom thick graphene filter.

Monday, May 16, 2016

Water Lens: Using Water To Purify Water?

Even though the concept is as zany as a Saturday Morning Cartoon premise, but can one use water to purify water making it safe to drink?
By: Ringo Bones

Two years ago, a Civil Engineering sophomore at the University of Buffalo named Deshawn Henry managed to use one of those zany Saturday Morning Cartoon premise as a working principle behind his device that uses water to purify water making it safe for everyone to drink. And best of all, the method is by far the most inexpensive way so far to provide constant supply of clean drinking water to over a billion people who still don’t have access to it. Unsafe drinking water results in the death of children below five years of age every minute, but Deshawn Henry’s invention could soon reduce childhood mortality due to a lack of access to clean drinking water. 

The device itself has a rather humble appearance, with a six-foot-tall frame of 2-by-4 pieces of lumber topped with a lens constructed of plastic sheeting and water which focuses down onto a treatment container for the water. The simplicity of the design and the inexpensive nature of the building materials mean that many living in impoverished areas would be able to obtain the technology and provide clean water for their families. Once operational, Henry’s Water Lens can eliminate up to 99.9-percent of pathogens in a liter of water in about an hour by magnifying sunlight and heating a liter of water to about 130 to 150 degrees Fahrenheit. All in all, given the promising initial results of being able to purify water using relatively low cost materials, Henry’s Water Lens is not bad for a “mere” summer project. 

Sunday, March 6, 2016

March 21 International Day of Forests: Environmentalism’s Watershed Moment?

Though we already have a lot of “red letter days” commemorating our embattled environment, is the March 21 International Day of Forests the most important of them all especially when it comes to securing a constant supply of safe drinking water?

By: Ringo Bones 

While Earth Hour may have succeeded in its intended environmental mission – i.e. crude oil prices had fallen 70-percent since 2014 – it seems that deforestation seems still like the most ignored issue of our embattled environment. South East Asian palm oil farms had been slashing and burning primeval forests / old-growth forests as if they’re growing out of fashion since the last decade of the 20th Century, it only has been relatively recently that the powers-that-be at the United Nations finally established a resolution to combat the increasing rate of global deforestation.  

The 21st day of March which was designated as The International Day of Forests was established by resolution of the United Nations General Assembly on November 28, 2014. Each year since then, various events celebrate and raise awareness of the importance of all types of forests and trees outside forests for the benefit of current and future generations. Countries are encouraged to undertake efforts to organize local, national and international activities involving forests and trees such as tree planting campaigns on March 21 – the International Day of Forests. The Secretariat of the United Nations Forum on Forests in collaboration with the Food and Agricultural Organization, facilitates the implementation of such events in collaboration with governments, the Collaborative Partnership on Forests and international, regional and subregional organizations. International Day of Forests was observed for the very first time on March 21, 2013. 

The catalyst for a “Forest Day” that lead to the establishment of the International Year of Forests started as a casual conversation between two scientists in Oxford, England back in February 2007 who felt that world at large was underestimating the importance of forests in mitigating carbon dioxide emissions and saw a growing need for the latest forestry research and thinking to inform global policy makers and the United Nations Framework Convention on Climate Change Conference of Parties negotiators. The two Oxford scientists did not foresee the conference would become one of the most influential global events on forests and climate change today. 

Each year since the 1970s, more than 13 million hectares or 32 million acres of forests are lost – an area roughly the size of England. As the forests vanishes so too are the plant and animal species that they embrace which make up 80 percent of all terrestrial biodiversity. Most importantly, forests play a critical role in mitigating the worst effects of climate change including global warming. Deforestation results in 12 to 18 percent of the world’s carbon dioxide emissions – almost equal to the carbon dioxide emissions of the entire global transportation sector. Equally crucial, healthy forests are one of the world’s primary carbon sinks. Today, forests cover more than 30 percent of the world’s land and contain more than 60,000 tree species many of them as yet unidentified and yet to be cataloged by the world’s botanical science community. Forests also provide food, fiber, clean drinking water and medicines for approximately 1.6 billion of the world’s poorest people who earn less than 1 US dollars a day – including indigenous peoples with unique cultures. And it has been scientifically proven for decades that rainfall tends to fall on forests and forests are currently the most cost effective way of purifying water in comparison to other man-made means.  

Sunday, January 31, 2016

Coal Seam Gas Extraction: Number One Cause of Groundwater Contamination?

Despite its scientifically proven low-carbon credentials, is coal seam gas extraction far from environmentally friendly due to its tendency to cause groundwater contamination?

By: Ringo Bones 

The energy firm Santos in New South Wales, Australia was picketed back in January 28, 2016 by local farmers due to its coal seam gas extraction schemes contaminating the local farmland’s groundwater source, but the energy firm’s “environmental impact” was already a concern almost two years ago. Back in March 24, 2014, leaks of water containing high levels of radioactive uranium from coal seam gas wastewater pond operated by energy firm Santos in New South Wales put the spotlight yet again on an industry already wracked by controversy. Most concerns over coal seam gas have to date focused on “fracking” – fracturing deep rock strata to get gas in coal seams – but as the incident shows, waste produced by coal seam gas wells and brought to the surface is another major environmental issue. 

According to the New South Wales Environmental Protection Authority, the March 2014 incident resulted in the contamination of the groundwater aquifer downstream of the leak that tested 20 times the acceptable levels of uranium for drinking water. This is concerning given the long timescales and effort involved in groundwater clean-up and the fact that the region affected is an area of recharge for the Great Artesian Basin. 

The type of wastewater that resulted in groundwater contamination in this incident – called “produced” or “co-produced” water – is generated in large quantities by all coal seam gas wells and it is usually of poor quality, containing potentially harmful levels of salts, radionuclides, metals and other contaminants. It appears that in this case such water was inappropriately stored in a leaky dam, allowing it to infiltrate and migrate into the underlying aquifer. 

The only viable way to rectify this is to use reverse osmosis to remove the contaminants and release the treated water into local streams but the method can be potentially cost prohibitive in some situations. Some contaminants – such as boron – are harder to remove and are retained in the treated coal seam gas extraction produced water. In some cases, methane can also remain in the water after it leaves the treatment plant, adding concerns of “fugitive emissions” given that methane is 20 times more potent than carbon dioxide as a greenhouse gas.  And this methane in the water has resulted in scores of sensational videos uploaded to You Tube where homeowners’ tap water catching fire after a lit match is brought close to a turned on faucet highlighting the environmental concerns of fracking. 

Saturday, August 22, 2015

Teri Dankovich’s Drinkable Book: Reliable Safe Drinking Water For The World’s Poorest?

Will Terry Dankovich’s “Drinkable Book” finally solve the reliability problem of safe drinking water supply for the world’s poorest citizens?

By: Ringo Bones 

By last count, as many as 358-million people in sub-Saharan Africa do not have a reliable access to safe clean drinking water. The good news is researchers have just come up with a book on water safety whose very pages can be used to filter water to make it safe to drink. Results of the trials done in 25 contaminated water sites in South Africa, Ghana, Kenya, Haiti and Bangladesh showed that the said book, which contains tiny particles of copper and silver, could eliminate over 99-percent of disease-causing bacteria as stated in the results of the project unveiled at the American Chemical Society’s national meeting that began back in August 16, 2015.  

Teri Dankovich, from Carnegie Mellon in Pittsburgh, who has been leading the research on what she calls “The Drinkable Book”, said in one trial that they tested a ditch contaminated with sewage that contained millions of disease-causing bacteria. Dankovich said: “even if highly contaminated water sources like the one we tested, we can achieve 99.9-percent purity with our silver-and-copper nanoparticle paper, bringing bacteria levels down comparable to those found in United States’ tap water”.  

Each paper of the pages in the Drinkable Book is embedded with silver and copper nanoparticles. The pages contain instructions in English and the local language the book is destined to. Water is poured and filtered through the pages themselves. One page can purify up to 100 liters – about 26 gallons – of water and one book can supply one person’s drinking water needs for about 4 years, the researchers said. The researchers currently make the books themselves – but are now looking to ramp up production and send the books to local communities.