PureMadi, a nonprofit University of Virginia organization,

PureMadi, a nonprofit University of Virginia organization, has invented a simple ceramic water purification tablet. Called MadiDrop, the tablet -- developed and extensively tested at U.Va. -- is impregnated with silver or copper nanoparticles. It can repeatedly disinfect water for up to six months simply by resting in a vessel where water is poured. It is being developed for use in communities in South Africa that have little or no access to clean water.

"Madi" is the Tshivenda South African word for water. PureMadi brings together U.Va. professors and students to improve water quality, human health, local enterprise and quality of life in the developing world. The organization includes students and faculty members from engineering, architecture, medicine, nursing, business, commerce, economics, anthropology and foreign affairs.

During the past year, PureMadi has established a water filter factory in Limpopo province, South Africa, employing local workers. The factory produced several hundred flowerpot-like water filters, according to James Smith, a U.Va. civil and environmental engineer who co-leads the project with Dr. Rebecca Dillingham, director of U.Va.'s Center for Global Health.

"Eventually that factory will be capable of producing about 500 to 1,000 filters per month, and our 10-year plan is to build 10 to 12 factories in South Africa and other countries," Smith said. "Each filter can serve a family of five or six for two to five years, so we plan to eventually serve at least 500,000 people per year with new filters."

The idea is to create sustainable businesses that serve their communities and employ local workers. A small percentage of the profits go back to PureMadi and will be used to help establish more factories.

The filters produced at the factory are made of a ceramic design refined and extensively tested at U.Va. The filters are made of local clay, sawdust and water. Those materials are mixed and pressed into a mold. The result is a flowerpot-shaped filter, which is then fired in a kiln. The firing burns off the sawdust, leaving a ceramic with very fine pores. The filter is then painted with a thin solution of silver or copper nanoparticles that serve as a highly effective disinfectant for waterborne pathogens, the type of which can cause severe diarrhea, vomiting and dehydration.

The design allows a user to pour water from an untreated source, such as a river or well, into the pot and allow it to filter through into a five-gallon bucket underneath. The pot has a flow rate of one to three liters per hour, enough for drinking and cooking. The filtered water is accessed through a spigot in the bucket.

U.Va. medical school studies are showing that use of the filters significantly improves health outcomes for users and are particularly beneficial to people with compromised immune systems, such as people living with AIDS. HIV prevalence is more than 17 percent among the general population in South Africa, and millions suffer each year from waterborne diseases. Smith said testing has shown that 99.9 percent of the pathogens in water can be removed or killed by the filter.

MadiDrop is an alternative to the flowerpot filter, but ideally would be used in conjunction with it. The plan is to mass-produce the product at the same factories where the PureMadi filters are produced.

"MadiDrop is cheaper, easier to use, and is easier to transport than the PureMadi filter, but because it is placed into the water, rather than having the water filter through it, the MadiDrop is not effective for removing sediment in water that causes discoloration or flavor impairment," Smith said. "But its ease of use, cost-effectiveness and simple manufacturing process should allow us to make it readily available to a substantial population of users, more so than the more expensive PureMadi filter."

Testing shows that the filters are safe to use and release only trace amounts of silver or copper particles, well within the safe water standards of the developed world. The filters also would be useful in rural areas of developed countries such as the United States where people rely on untreated well water.

Sydney's iconic harbour has played a starring role in the development of new CSIRO technology that could save lives around the world.

Sydney's iconic harbour has played a starring role in the development of new CSIRO technology that could save lives around the world.

Using their own specially designed form of graphene, 'Graphair', CSIRO scientists have supercharged water purification, making it simpler, more effective and quicker.

The new filtering technique is so effective, water samples from Sydney Harbour were safe to drink after passing through the filter.

The breakthrough research was published today in Nature Communications.

"Almost a third of the world's population, some 2.1 billion people, don't have clean and safe drinking water," the paper's lead author, CSIRO scientist Dr Dong Han Seo said.

"As a result, millions -- mostly children -- die from diseases associated with inadequate water supply, sanitation and hygiene every year.

"In Graphair we've found a perfect filter for water purification. It can replace the complex, time consuming and multi-stage processes currently needed with a single step."

While graphene is the world's strongest material and can be just a single carbon atom thin, it is usually water repellent.

Using their Graphair process, CSIRO researchers were able to create a film with microscopic nano-channels that let water pass through, but stop pollutants.

As an added advantage Graphair is simpler, cheaper, faster and more environmentally friendly than graphene to make.

It consists of renewable soybean oil, more commonly found in vegetable oil.

Looking for a challenge, Dr Seo and his colleagues took water samples from Sydney Harbour and ran it through a commercially available water filter, coated with Graphair.

Researchers from QUT, the University of Sydney, UTS, and Victoria University then tested and analysed its water purification qualities.

The breakthrough potentially solves one of the great problems with current water filtering methods: fouling.

Over time chemical and oil based pollutants coat and impede water filters, meaning contaminants have to be removed before filtering can begin. Tests showed Graphair continued to work even when coated with pollutants.

Without Graphair, the membrane's filtration rate halved in 72 hours.

When the Graphair was added, the membrane filtered even more contaminants (99 per cent removal) faster.

"This technology can create clean drinking water, regardless of how dirty it is, in a single step," Dr Seo said.

"All that's needed is heat, our graphene, a membrane filter and a small water pump. We're hoping to commence field trials in a developing world community next year."

CSIRO is looking for industry partners to scale up the technology so it can be used to filter a home or even town's water supply.

It's also investigating other applications such as the treatment of seawater and industrial effluents.

Dengan menggunakan proses Graphair mereka,

Pelabuhan ikonik Sydney telah memainkan peranan yang membintangi pembangunan teknologi CSIRO baru yang boleh menyelamatkan nyawa di seluruh dunia. Dengan menggunakan grafene mereka sendiri, 'Graphair', para saintis CSIRO telah melakukan pembersihan air yang supercharged, menjadikannya lebih mudah, lebih berkesan dan lebih cepat. Teknik penapisan baru begitu berkesan, sampel air dari Sydney Harbour selamat diminum setelah melalui penapis. Penyelidikan kejayaan telah diterbitkan hari ini dalam Komunikasi Alam. "Hampir satu pertiga daripada penduduk dunia, kira-kira 2.1 bilion orang, tidak mempunyai air minuman yang bersih dan selamat," kata penulis saintis CSIRO Dr Dong Han Seo. "Akibatnya, berjuta-juta - kebanyakannya kanak-kanak - mati akibat penyakit yang berkaitan dengan bekalan air, sanitasi dan kebersihan yang tidak mencukupi setiap tahun. "Di Graphair kami telah menemui penapis yang sempurna untuk pembersihan air. Ia boleh menggantikan proses kompleks, memakan masa dan multi-tahap yang diperlukan saat ini dengan satu langkah." Walaupun graphene adalah bahan terkuat di dunia dan boleh menjadi hanya satu atom karbon tipis, biasanya penolak air. Dengan menggunakan proses Graphair mereka, para penyelidik CSIRO dapat membuat filem dengan nano-saluran mikroskopik yang membolehkan air melewati, tetapi menghentikan pencemaran. Sebagai kelebihan tambahan, Graphair adalah lebih mudah, lebih murah, lebih cepat dan lebih mesra alam berbanding graphene. Ia terdiri daripada minyak kacang soya yang boleh diperbaharui, yang lebih biasa dijumpai dalam minyak sayuran. Mencari cabaran, Dr Seo dan rakan-rakannya mengambil sampel air dari Sydney Harbour dan berlari melalui penapis air yang tersedia secara komersial, disalut dengan Graphair. Penyelidik dari QUT, Universiti Sydney, UTS, dan Victoria University kemudian menguji dan menganalisis kualiti penulenan airnya. Penemuan ini berpotensi memecahkan salah satu masalah besar dengan kaedah penapisan air semasa: menjejaskan. Dari masa ke masa bahan kimia dan berasaskan minyak cemar kot dan menghalang penapis air, bermakna pencemaran perlu dikeluarkan sebelum penapisan boleh bermula. Ujian menunjukkan Graphair terus bekerja walaupun disalut dengan bahan pencemar. Tanpa Graphair, kadar penapisan membran dibelahkan dalam 72 jam. Apabila Graphair ditambah, membran yang ditapis lebih banyak bahan cemar (penyingkiran 99 peratus) lebih cepat. "Teknologi ini boleh mencipta air minuman yang bersih, tanpa mengira betapa kotor, dalam satu langkah," kata Dr Seo. "Apa yang diperlukan ialah haba, grafena, penapis membran dan pam air kecil. Kami berharap dapat memulakan ujian lapangan dalam komuniti dunia yang sedang membangun tahun depan." CSIRO mencari rakan kongsi industri untuk meningkatkan teknologi supaya dapat digunakan untuk menapis bekalan air di rumah atau di bandar. Ia juga menyiasat aplikasi lain seperti rawatan air kumbahan dan efluen perindustrian.

Graphene oxide telah dipuji sebagai bahan keajaiban yang benar;

Graphene oxide telah dipuji sebagai bahan keajaiban yang benar; apabila dimasukkan ke dalam busa nanoselulosa, bahan buih yang dicipta adalah ringan, kuat dan fleksibel, menjalankan haba dan elektrik dengan cepat dan cekap.

Sekarang, satu pasukan jurutera di Washington University di St Louis telah menemui satu cara untuk menggunakan lembaran graphene oxide untuk mengubah air kotor menjadi air minuman, dan ia boleh menjadi permainan changer global.

"Kami berharap agar negara-negara di mana terdapat banyak cahaya matahari, seperti India, anda akan dapat mengambil air yang kotor, menguapnya menggunakan bahan kami, dan mengumpul air tawar," kata Srikanth Singamaneni, profesor kejuruteraan mekanikal dan bahan sains di Sekolah Kejuruteraan & Sains Gunaan.

Pendekatan baru menggabungkan selulosa yang dihasilkan bakteria dan graphene oxide untuk membentuk biofoam bi-layered. Satu kertas yang memperincikan penyelidikan boleh didapati dalam talian dalam Bahan Advanced.

"Prosesnya sangat mudah," kata Singamaneni. "Keindahannya ialah rangkaian gentian selulosa nano yang dihasilkan oleh bakteria mempunyai keupayaan yang sangat baik menggerakkan air dari pukal ke permukaan yang menguap dan meminimumkan haba turun, dan keseluruhannya dihasilkan dalam satu pukulan.

"Reka bentuk bahan adalah novel di sini," kata Singamaneni. "Anda mempunyai satu struktur berlapis ganda dengan nanoselulosa yang diisi dengan grafene oksida yang diisi nanoselulosa di atas dan nanoselulosa di bahagian bawah. Apabila anda menangguhkan seluruh benda ini di atas air, air tersebut sebenarnya dapat mencapai permukaan teratas di mana penyejatan berlaku.

"Cahaya memancarkan di atasnya, dan ia berubah menjadi panas kerana oksida graphene - tetapi pelesapan haba ke air pukal di bawah diminimumkan oleh lapisan nanoselulosa yang murni.Anda tidak mahu membazirkan haba; keluarkan haba ke lapisan atas di mana penyejatan sebenarnya berlaku. "

Selulosa di bahagian bawah biofoam berlapis dua bertindak sebagai spons, menarik air sehingga oksida graphene di mana penyejatan cepat berlaku. Air segar yang dihasilkan dapat dikumpulkan dari bahagian atas lembaran.

Proses di mana biofoam bi-layered sebenarnya terbentuk juga novel. Dengan cara yang sama, sebuah tiram membuat mutiara, bakteria membentuk lapisan gentian nanocellulosa di mana serpihan grafena oksida tertanam.

"Walaupun kami membiak bakteria untuk selulosa, kami menambah serpihan graphene oksida ke medium itu sendiri," kata Qisheng Jiang, pengarang utama kertas dan pelajar siswazah di makmal Singamaneni.

"Grafena oksida menjadi tertanam sebagai bakteria menghasilkan selulosa. Pada titik tertentu sepanjang proses ini, kita berhenti, mengeluarkan medium dengan graphene oxide dan memperkenalkan semula medium segar yang menghasilkan lapisan seterusnya kami buih. ; secara mekanikal, ia agak teguh. "

Biofoam baru juga sangat ringan dan murah untuk membuat, menjadikannya alat yang sesuai untuk pembersihan air dan penyahgaraman.

"Selulosa dapat dihasilkan secara besar-besaran," kata Singamaneni, "dan graphene oxide sangat murah - orang dapat menghasilkan tan, benar-benar ton, itu. Kedua-dua bahan yang masuk ke dalam ini sangat berskala. daripada biofoam. "

"Ciri-ciri bahan buih ini yang kami sintetik mempunyai ciri-ciri yang meningkatkan penuaian tenaga solar, oleh itu, ia lebih berkesan dalam membersihkan air," kata Pratim Biswas, Lucy dan Stanley Lopata Profesor dan ketua Jabatan Tenaga, Alam Sekitar dan Kejuruteraan kimia.

"Proses sintesis juga membolehkan penambahan bahan nanostructured lain ke buih yang akan meningkatkan kadar kemusnahan bakteria dan bahan pencemar lain, dan menjadikannya selamat untuk diminum. Kami juga akan meneroka aplikasi lain untuk struktur novel ini."

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."