Graphene oxide has been hailed as a veritable wonder material

Graphene oxide has been hailed as a veritable wonder material; when incorporated into nanocellulose foam, the lab-created substance is light, strong and flexible, conducting heat and electricity quickly and efficiently.

Now, a team of engineers at Washington University in St. Louis has found a way to use graphene oxide sheets to transform dirty water into drinking water, and it could be a global game-changer.

"We hope that for countries where there is ample sunlight, such as India, you'll be able to take some dirty water, evaporate it using our material, and collect fresh water," said Srikanth Singamaneni, associate professor of mechanical engineering and materials science at the School of Engineering & Applied Science.

The new approach combines bacteria-produced cellulose and graphene oxide to form a bi-layered biofoam. A paper detailing the research is available online in Advanced Materials.

"The process is extremely simple," Singamaneni said. "The beauty is that the nanoscale cellulose fiber network produced by bacteria has excellent ability move the water from the bulk to the evaporative surface while minimizing the heat coming down, and the entire thing is produced in one shot.

"The design of the material is novel here," Singamaneni said. "You have a bi-layered structure with light-absorbing graphene oxide filled nanocellulose at the top and pristine nanocellulose at the bottom. When you suspend this entire thing on water, the water is actually able to reach the top surface where evaporation happens.

"Light radiates on top of it, and it converts into heat because of the graphene oxide -- but the heat dissipation to the bulk water underneath is minimized by the pristine nanocellulose layer. You don't want to waste the heat; you want to confine the heat to the top layer where the evaporation is actually happening."

The cellulose at the bottom of the bi-layered biofoam acts as a sponge, drawing water up to the graphene oxide where rapid evaporation occurs. The resulting fresh water can easily be collected from the top of the sheet.

The process in which the bi-layered biofoam is actually formed is also novel. In the same way an oyster makes a pearl, the bacteria forms layers of nanocellulose fibers in which the graphene oxide flakes get embedded.

"While we are culturing the bacteria for the cellulose, we added the graphene oxide flakes into the medium itself," said Qisheng Jiang, lead author of the paper and a graduate student in the Singamaneni lab.

"The graphene oxide becomes embedded as the bacteria produces the cellulose. At a certain point along the process, we stop, remove the medium with the graphene oxide and reintroduce fresh medium. That produces the next layer of our foam. The interface is very strong; mechanically, it is quite robust."

The new biofoam is also extremely light and inexpensive to make, making it a viable tool for water purification and desalination.

"Cellulose can be produced on a massive scale," Singamaneni said, "and graphene oxide is extremely cheap -- people can produce tons, truly tons, of it. Both materials going into this are highly scalable. So one can imagine making huge sheets of the biofoam."

"The properties of this foam material that we synthesized has characteristics that enhances solar energy harvesting. Thus, it is more effective in cleaning up water," said Pratim Biswas, the Lucy and Stanley Lopata Professor and chair of the Department of Energy, Environmental and Chemical Engineering.

"The synthesis process also allows addition of other nanostructured materials to the foam that will increase the rate of destruction of the bacteria and other contaminants, and make it safe to drink. We will also explore other applications for these novel structures."

Penyelidikan yang diketuai oleh profesor hidrologi Profesor Richard Brazier mendapati bahawa

Kajian yang dilakukan oleh para saintis di Universiti Exeter menggunakan percubaan berang-berang yang dikendalikan oleh Devon Wildlife Trust, telah menunjukkan kesan yang ketara terhadap haiwan untuk mengurangkan aliran tan tanah dan nutrien dari ladang yang berdekatan ke dalam sistem sungai tempatan .

Penyelidikan yang diketuai oleh profesor hidrologi Profesor Richard Brazier mendapati bahawa kerja keluarga tunggal berang telah menghilangkan sedimen, nitrogen dan fosforus yang tinggi dari air yang mengalir melalui kandang seluas 2.5 hektar.

Keluarga pemetik api, yang tinggal di lokasi berpagar di lokasi rahsia di West Devon sejak tahun 2011, telah membina 13 empangan, memperlambat aliran air dan mewujudkan satu siri kolam dalam sepanjang aliran yang kecil.

Penyelidik mengukur jumlah sedimen yang ditangguhkan, fosforus dan nitrogen dalam air yang mengalir ke tapak tersebut dan kemudian membandingkannya dengan air kerana ia kehabisan tapak yang telah melalui kolam dan empangan beaver. Mereka juga mengukur jumlah sedimen, fosforus dan nitrogen yang terperangkap oleh empangan di setiap kolam.

Keputusan mereka menunjukkan empangan telah terperangkap lebih daripada 100 tan metrik sedimen, 70% daripadanya adalah tanah, yang terkikis dari hulu 'padang rumput yang dikendalikan secara intensif' di hulu. Siasatan lanjut mendedahkan bahawa sedimen ini mengandungi kepekatan nitrogen dan fosforus yang tinggi, iaitu nutrien yang dikenali untuk menimbulkan masalah untuk hidupan liar di sungai dan sungai dan yang juga perlu dikeluarkan dari bekalan air manusia untuk memenuhi standard kualiti minum.

Penyelidikan ini dibiayai oleh Westland Countryside Stewards dan Majlis Penyelidikan Alam Semulajadi dan dijalankan oleh sebuah pasukan dari University of Exeter yang diketuai oleh Profesor Earth Surface Processes, Richard Brazier.

Profesor Brazier berkata: "Adalah menjadi perhatian serius bahawa kita melihat kadar kehilangan tanah yang tinggi dari tanah pertanian, yang lebih baik daripada kadar pembentukan tanah. Walau bagaimanapun, kami berasa sedih untuk mengetahui bahawa empangan beaver boleh pergi jauh untuk mengurangkan kehilangan tanah ini dan juga perangkap bahan pencemar yang membawa kepada kemusnahan badan air kita. Kerana peremajaan menjadi sesuatu yang biasa dalam landskap, kita pasti akan melihat kesan ini memberikan pelbagai faedah di seluruh ekosistem, seperti yang mereka lakukan di tempat lain di seluruh dunia. "

Penemuan penyelidikan mengenai kesan positif beruang di atas kehilangan hakisan tanah dan pencemaran dalam kursus air datang pada masa yang semakin membimbangkan isu-isu ini. Pada tahun 2009 kajian berasingan menganggarkan bahawa jumlah kos kehilangan tanah dari tanah pertanian UK adalah £ 45million, sebahagian besarnya disebabkan oleh kesan sedimen dan pencemaran nutrien hiliran.

Devon Wildlife Trust telah menjalankan percubaan berangin tertutup selama tujuh tahun, manakala sejak tahun 2015 ia juga telah menjalankan satu lagi projek berang-berang yang melibatkan populasi pemangsa liar di Sungai Otter, East Devon.

Pengarah Pemuliharaan dan Pembangunan amal, Peter Burgess berkata: "Perkongsian kami dengan Exeter University yang mengendalikan kedua-dua ujian pemangak kami yang berpagar dan dipijak itu mendedahkan maklumat yang menunjukkan memerang peranan penting dapat dimainkan, bukan sahaja untuk hidupan liar, tetapi kemampanan masa depan kami tanah dan air. Ia benar-benar memberi inspirasi untuk membuat pemerhatian kami disahkan oleh siasatan saintifik yang terperinci. "

The study, undertaken by scientists at the University of

The study, undertaken by scientists at the University of Exeter using a captive beaver trial run by the Devon Wildlife Trust, has demonstrated the significant impact the animals have had on reducing the flow of tonnes of soil and nutrients from nearby fields into a local river system.

The research, led by hydrologist Professor Richard Brazier, found that the work of a single family of beavers had removed high levels of sediment, nitrogen and phosphorus from the water that flowed through their 2.5 hectare enclosure.

The family of beavers, which have lived in fenced site at a secret location in West Devon since 2011, have built 13 dams, slowing the flow of water and creating a series of deep ponds along the course of what was once a small stream.

Researchers measured the amount of sediment suspended, phosphorus and nitrogen in water running into the site and then compared this to water as it ran out of the site having passed through the beavers' ponds and dams. They also measured the amount of sediment, phosphorus and nitrogen trapped by the dams in each of the ponds.

Their results showed the dams had trapped more than 100 tonnes of sediment, 70% of which was soil, which had eroded from 'intensively managed grassland' fields upstream. Further investigation revealed that this sediment contained high concentrations of nitrogen and phosphorus, which are nutrients known to create problems for the wildlife in rivers and streams and which also need to be removed from human water supplies to meet drinking-quality standards.

The research was funded by Westland Countryside Stewards and the Natural Environment Research Council and conducted by a team from the University of Exeter led by Professor of Earth Surface Processes, Richard Brazier.

Professor Brazier said: "It is of serious concern that we observe such high rates of soil loss from agricultural land, which are well in excess of soil formation rates. However, we are heartened to discover that beaver dams can go a long way to mitigate this soil loss and also trap pollutants which lead to the degradation of our water bodies. Were beaver dams to be commonplace in the landscape we would no doubt see these effects delivering multiple benefits across whole ecosystems, as they do elsewhere around the world."

The research findings about beavers' positive impact on soil erosion losses and pollution in water courses come at a time of growing concern about these issues. In 2009 a separate study estimated that the total cost of soil loss from the UK's agricultural land was £45million, much of which was due to the impacts of sediment and nutrient pollution downstream.

Devon Wildlife Trust has been conducting its enclosed beaver trial for seven years, while since 2015 it has also been running another beaver project involving a population of wild-living beavers on the River Otter, East Devon.

The charity's Director of Conservation and Development, Peter Burgess said: "Our partnership with Exeter University working on both our fenced and unfenced beaver trials is revealing information which shows the critical role beavers can play, not only for wildlife, but the future sustainability of our land and water. It is truly inspiring to have our observations confirmed by detailed scientific investigations."

Dirty Water Causes Millions of People..

Dirty Water Causes Millions of People At Risky Attacked Diseases



The United Nations Environment Program (UNEP) says more than 300 million people in Asia, Africa and Latin America are at risk of disease due to increased water pollution in rivers and lakes. According to the UNEP report, between 1990 and 2010 there was an increase in pollution of the river that caused the development of the virus to bacteria. Population growth, agricultural expansion, and the increased amount of waste disposed to the river and are the main factors in increasing water pollution. "Water quality issues on a global scale and the number of people affected by bad water quality are far worse than we think," UNEP author Dietrich Borchardt told Thomson Reuters Foundation. In the report it is also revealed, the Asian region has the largest pollution of the river, which is about 50 percent of the river has been polluted. Meanwhile, river pollution in Latin America is 10 percent and 25 percent in Africa. UNEP data shows that at least 3.5 million people die each year due to cholera, typhoid, polio, and diarrhea due to bacterial infections from dirty water. UNEP estimates that currently there are 164 million people in Africa, 134 million in Asia and 25 million in Latin America who are at risk of illness due to poor water or sanitation. According to UNEP, river pollution is a serious problem that can not be realized to be deadly. UNEP recommends good waste treatment. In addition, clean streams should be completely protected from pollution.

Penyelidik di Tufts University telah mendapati bahawa lebah madu mengubah diet

Penyelidik di Tufts University telah mendapati bahawa lebah madu mengubah diet mereka nutrien mengikut musim, terutamanya ketika musim sejuk. Satu peningkatan dalam penggunaan kalsium pada musim gugur, dan pengambilan kalium yang tinggi, membantu menyediakan lebah untuk bulan-bulan yang lebih sejuk apabila mereka mungkin memerlukan mineral-mineral tersebut untuk menjana kehangatan melalui kontraksi otot yang cepat. Penyediaan berhati-hati mengenai pengambilan nutrien lebah menunjukkan sumber peralihan (dari bunga ke air kotor yang kaya dengan air kotor) dan bagaimana batasan ketersediaan nutrien dari sumber-sumber ini dapat memberi implikasi bagi kesihatan koloni yang diurus dan liar.

Kajian yang boleh didapati dalam edisi cetakan Mei Journal of Insect Physiology, mengkaji kandungan mineral yang dikumpulkan oleh dan terkandung dalam lebah dewasa dan sumber makanan mereka, meneroka bagaimana mereka mengekalkan keseimbangan pemakanan nutrisi mikronutrien. Bagi sebahagian besar mineral yang dikesan, didapati lebah mencari sumber alternatif untuk melengkapi variasi dalam bekalan bunga.

"Kami biasanya memikirkan lebah madu sebagai mengumpul semua makanan yang mereka perlukan untuk tanah jajahan dari bunga, tetapi pada kenyataannya, penyelidikan kami menunjukkan bahawa lebah mencari secara strategik di antara sumber yang berbeda, termasuk air, untuk meningkatkan toko kalsium dan menjaga kadar kalium dalam persiapan untuk musim sejuk, "kata Philip Starks, profesor biologi bersekutu di Sekolah Seni dan Sains di Tufts. "Keperluan pemakanan madu lebah agak rumit, dan mereka mungkin menghadapi batasan kerana tahap mikronutrien dalam persekitaran mereka."

Penemuan kajian membina penyelidikan terdahulu yang diketuai oleh Dr. Rachael Bonoan dari makmal Starks yang mendedahkan bahawa lebah madu menggunakan sumber air untuk melengkapi, dan kadang-kadang menambah, mineral dalam diet bunga mereka. Sebagai contoh, apabila paras magnesium jatuh dalam debunga semasa musim panas dan musim gugur, lebah mengambil perbezaan dari air kaya mineral. Sebagai alternatif, tahap kalsium dalam peningkatan debunga berkumpul pada musim gugur, tetapi begitu juga keutamaan lebah untuk kalsium dalam air, mungkin mencerminkan pergeseran dari pembiakan brood ke overwintering, para penyelidik berspekulasi. Kalsium dan kalium yang banyak berguna untuk aktiviti otot yang diperlukan untuk menghasilkan haba dalam sarang semasa musim sejuk.

"Keputusan ini mempunyai implikasi di lapangan," kata Rachael Bonoan, pengarang utama kajian dan Ph.D. lulusan dari Starks Lab. "Akhirnya, salah satu matlamat untuk mengkaji keperluan mineral madu adalah untuk membuat diet tambahan musim-atau spesifik tanaman untuk pemeliharaan lebah. Di luar lebah madu, kita dapat menyokong pendebunga liar dengan menanam bunga yang beragam, dan dengan demikian kaya sumber nutrien. "

Terdapat banyak faktor yang telah dipersalahkan untuk penurunan populasi lebah baru-baru ini, termasuk penggunaan racun perosak, kemunculan parasit dan patogen, dan perubahan iklim. Walaupun kepelbagaian dalam bekalan makanan mungkin satu faktor, kesannya terhadap krisis lebah madu belum ditentukan. Kajian ini, bagaimanapun, memperluaskan pemahaman kita terhadap keperluan pemakanan dinamik koloni lebah dan memberikan wawasan lanjut tentang bagaimana kita dapat menguruskan kesihatan populasi lebah madu yang menyokong persekitaran semula jadi dan bekalan makanan kita.

Juga menyumbang kepada kajian itu adalah sarjana muda Tufts University, Luke O'Connor, yang kerja-kerja membentuk asas tesis kehormatan utamanya.

Researchers at Tufts University have discovered that honey bees

Researchers at Tufts University have discovered that honey bees alter their diet of nutrients according to the season, particularly as winter approaches. A spike in calcium consumption in the fall, and high intake of potassium, help prepare the bees for colder months when they likely need those minerals to generate warmth through rapid muscle contractions. A careful inventory of the bees' nutrient intake revealed shifting sources (from flowers to mineral rich 'dirty water') and how limitations in nutrient availability from these sources can have implications for the health of both managed and wild colonies.

The study, which is available in the May print edition of the Journal of Insect Physiology, examined mineral content gathered by and contained in adult bees and in their sources of food, exploring how they maintain the right nutritional balance of micronutrients. For most of the minerals tracked, it was found that the bees sought alternate sources to complement variation in the floral supply.

"We typically think of honey bees as gathering all the food they need for the colony from flowers, but in fact, our research showed that bees search strategically among different sources, including water, to boost their stores of calcium and maintain potassium levels in preparation for the cold season," said Philip Starks, associate professor of biology in the School of Arts and Sciences at Tufts. "Honey bee nutritional requirements are quite complex, and they can face limitations because of levels of micronutrients in their environment."

The study findings build on previous research led by Dr. Rachael Bonoan from the Starks lab that revealed that honey bees use water sources to complement, and sometimes supplement, the minerals in their floral diet. For example, as magnesium levels drop in pollen during the summer and fall, the bees pick up the difference from mineral rich water. Alternatively, calcium levels in gathered pollen increase in the fall, but so do the bees' preference for calcium in water, perhaps reflecting a shift from brood rearing to overwintering, the researchers speculate. Ample calcium and potassium are useful for the muscle activity needed to generate heat in the hive during the winter months.

"These results have implications in the field," said Rachael Bonoan, lead author of the study and recent Ph.D. graduate from the Starks Lab. "Ultimately, one of the goals of studying mineral needs of honey bees is to create season- or crop-specific supplemental diets for beekeepers. Beyond honey bees, we can support wild pollinators by planting diverse floral, and thus nutrient-rich, sources."

There are many factors that have been blamed for the recent decline of bee populations, including the use of pesticides, the emergence of parasites and pathogens, and climate change. While diversity in the food supply may be one factor, its relative impact on the honey bee crisis has not yet been determined. This particular study, however, expands our understanding of the dynamic nutritional needs of bee colonies and provides further insight as to how we might manage the health of honey bee populations that support the natural environment and our food supply.

Also contributing to the study was Tufts University undergraduate Luke O'Connor, whose work formed the basis of his senior honor's thesis.

Water purification

Water purification is the removal of contaminants from raw water to produce drinking water that is pure enough for human consumption or for industrial use.

Substances that are removed during the process include parasites (such as Giardia or Cryptosporidium) , bacteria, algae, viruses, fungi, minerals (including toxic metals such as Lead, Copper etc.), and man-made chemical pollutants.

Many contaminants can be dangerous—but depending on the quality standards, others are removed to improve the water's smell, taste, and appearance.

A small amount of disinfectant is usually intentionally left in the water at the end of the treatment process to reduce the risk of re-contamination in the distribution system.

Many environmental and cost considerations affect the location and design of water purification plants.

Groundwater is cheaper to treat, but aquifers usually have limited output and can take thousands of years to recharge.

Surface water sources should be carefully monitored for the presence of unusual types or levels of microbial/disease causing contaminants.

The treatment plant itself must be kept secure from vandalism and terrorism.

It is not possible to tell whether water is safe to drink just by looking at it.

Simple procedures such as boiling or the use of a household charcoal filter are not sufficient for treating water from an unknown source.

Even natural spring water - considered safe for all practical purposes in the 1800s - must now be tested before determining what kind of treatment is needed.