MMaterialsgateNEWS 2017/06/12

Related MaterialsgateCARDS

Nanoparticles and Magnets Offer New, Efficient Method of Removing Oil from Water

When oil mixes with or enters into water, conventional methods of cleaning the water and removing the oil can be challenging, expensive and environmentally risky.

But researchers in the Cockrell School of Engineering at The University of Texas at Austin believe they may have developed a better method.

In a study published this spring in the Journal of Nanoparticle Research, the researchers used magnetic nanoparticles to separate oil from water through a simple process that relies on electrostatic force and a magnet. The engineers believe their new technique could improve water treatment for oil and gas production, more efficiently clean up oil spills and potentially remove lead from drinking water.

Today, nanoparticles, which are tiny particles that can be coated with different chemicals such as polymers, are used in a wide variety of areas and industries including medicine, energy and electronics. The versatility of nanoparticles inspired the UT Austin team to explore how the particles could be applied to oil production to lessen its environmental footprint and increase efficiency in both onshore and offshore drilling. They believe their technique could also be used to treat the millions of gallons of fresh water used in hydraulic fracturing and to help clean drinking water.

Modern oil production methods separate 95 percent of the oil from produced water but leave behind small oil droplets that are difficult to extract, which makes water treatment and disposal more challenging and environmentally risky.

“This new technique is really aimed at removing that little bit of oil in that water that needs to be removed before you can consider it treated,” said Saebom Ko, a research associate in the Department of Petroleum and Geosystems Engineering and lead author on the study. “The advantage of employing magnetic nanoparticles is that the small oil droplets that attach to the nanoparticles are much more quickly separated from water than traditional physical separation processes because magnetic force can be orders of magnitude larger than gravitation.”

Ko worked with a team including petroleum and geosystems engineering professor Hugh Daigle, biomedical engineering professor Thomas Milner and researcher Chun Huh to design surface coatings for magnetic nanoparticles that could be used for the removal of oil. They employed a technique, called high gradient magnetic separation, that has been used in mining to remove metals and in the food industry to remove toxic particles.

The team’s main advancement is designing surface coatings for nanoparticles that are able to adhere to oil droplets using electrostatic force. The team coated the magnetic nanoparticles with polymers whose surface charge is positive. The positively charged magnetic nanoparticles then latch on to the negatively charged oil droplets through electrostatic attractive force, similar to how a dust-trapping cloth picks up dust. The process — which takes seconds in laboratory tests— could also happen in reverse. If the target substances have positive surface charges, the magnetic nanoparticles could be coated with negatively charged polymers to attract the target.

“It’s a simple idea,” Daigle said. “We are leveraging the magnetic properties of these nanoparticles to get them to stick to the oil droplets and essentially magnetize the oil droplets so they can be pulled out with a magnet.”

The ease of the technique and the flexibility of magnetic nanoparticles have motivated the researchers to consider different applications.

“The applications can extend far beyond the oil field because, with an appropriate surface coating design, you can take your magnetic core and coat it with whatever chemical you choose on the outside to stick to the target and pull it out with a magnet,” Daigle said.

The researchers have envisioned designing a method for using these nanoparticles to clean up oil spills in the ocean. They are also exploring how magnetic nanoparticles can be used to remove lead and other contaminants from drinking water, with plans to test their ideas this summer.

For oil and gas production, the team plans to develop a treatment system that would have the capacity to rapidly handle a high volume of oil and water, which would be crucial for onshore and offshore oil drilling sites.

“We are currently developing a chemical-free regeneration process to reuse nanoparticles. Other regeneration methods use chemicals to extract the oil, resulting in production of other hazardous waste,” Ko said. “We believe that by recycling and reusing nanoparticles, it could not only reduce operational costs, but it could be an environmentally friendly process that reduces hazardous waste.”

Source: University of Texas at Austin – 08.06.2009.

Investigated and edited by:

Dr.-Ing. Christoph Konetschny, Inhaber und Gründer von Materialsgate
Büro für Material- und Technologieberatung
The investigation and editing of this document was performed with best care and attention.
For the accuracy, validity, availability and applicability of the given information, we take no liability.
Please discuss the suitability concerning your specific application with the experts of the named company or organization.

You want additional material or technology investigations concerning this subject?

Materialsgate is leading in material consulting and material investigation.
Feel free to use our established consulting services

MMore on this topic

In hopes of limiting the disastrous environmental effects of massive oil spills, materials scientists from Drexel University and Deakin University, in Australia, have teamed up to manufacture and test a new material, called a boron nitride nanosheet, that can absorb up to 33 times its weight in oils and organic solvents--a trait that could make it an important technology for quickly mitigating these costly accidents.

The material, which literally absorbs the oil like a sponge, is the result of support from the Australian Research Council and is now ready to be tested by industry after two years of refinement in the laboratory at Deakin's Institute for Frontier Materials (IFM). Alfred Deakin Professor Ying (Ian) Chen, PhD, the lead author of a paper, recently published in Nature Communications, said the material is the most exciting advancement in oil spill remediation technology in decades. "Oil spills are a global problem and wreak havoc on our aquatic ecosystems, not to mention cost billions of dollars in damage," Chen said. "Everyone remembers the Gulf Coast disaster, but here... more read more

Nano-coated mesh could clean oil spills for less than $1 per square foot

The unassuming piece of stainless steel mesh in a lab at The Ohio State University doesn't look like a very big deal, but it could make a big difference for future environmental cleanups. Water passes through the mesh but oil doesn't, thanks to a nearly invisible oil-repelling coating on its surface. In tests, researchers mixed water with oil and poured the mixture onto the mesh. The water filtered through the mesh to land in a beaker below. The oil collected on top of the mesh, and rolled off easily into a separate beaker when the mesh was tilted. The mesh coating is among a suite of nature-inspired nanotechnologies under development at Ohio State and described in two papers... more read more

In an advance toward stain-proof, spill-proof clothing, protective garments and other products that shrug off virtually every liquid — from blood and ketchup to concentrated acids — scientists are reporting development of new "superomniphobic" surfaces.

Their report on surfaces that display extreme repellency to two families of liquids — Newtonian and non-Newtonian liquids — appears in the Journal of the American Chemical Society. Anish Tuteja and colleagues point out that scientists have previously reported "omniphobic" surfaces, the term meaning that such surfaces can cause a range of different liquids to bead up and not spread on them. But typically very low surface tension liquids such as some oils and alcohols can adhere to those surfaces. Further, scientists have mostly focused on making surfaces that repel only one of the two families of liquids — Newtonian liquids, named for the great English scientist who described... more read more

Scientists are describing what may be a "complete solution" to cleaning up oil spills — a superabsorbent material that sops up 40 times its own weight in oil and then can be shipped to an oil refinery and processed to recover the oil. Their article on the material appears in ACS' journal Energy & Fuels.

T. C. Mike Chung and Xuepei Yuan point out that current methods for coping with oil spills like the 2010 Deepwater Horizon disaster are low-tech, decades-old and have many disadvantages. Corncobs, straw and other absorbents, for instance, can hold only about 5 times their own weight and pick up water, as well as oil. Those materials then become industrial waste that must be disposed of in special landfills or burned. Their solution is a polymer material that transforms an oil spill into a soft, solid oil-containing gel. One pound of the material can recover about 5 gallons of crude oil. The gel is strong enough to be collected and transported. Then, it can be converted to a liquid and refined... more read more

MaterialsgateNEWSLETTER

Partner of the Week

Search in MaterialsgateNEWS

Books and products

MaterialsgateFAIR:
LET YOURSELF BE INSPIRED