Porous Polymer Mats for the Removal of Oil Spills on Water
Sat, April 17, 2021

Porous Polymer Mats for the Removal of Oil Spills on Water

 

Oil spills remain a global threat to marine environments, wildlife, and humans despite the safety measures that oil and gas companies have been implementing. For instance, detecting gas leaks poses a big challenge to these firms because some gases are odorless and colorless that it takes time to discover the leak. Just recently, a preventable oil spill in Ecuador’s Amazon region in the time of coronavirus has put Indigenous lives at risk. The Amazonian people living in one of the most biodiverse hotspots in the world have suddenly found that the crops and fish that would enable them to self-isolate in the forest are contaminated by oil.

But what if there’s an easier and simpler way to clean up an oil spill? This inspired a team of researchers from King Abdullah University of Science and Technology in Saudi Arabia to use a polymer called 6FDA-TrMPD. The material has important features for adsorbing the spilled oil in water, such as it is “intrinsically porous.”

Electrospinning of 6FDA-TrMPD polymer

Fuat Topuz from KAUST’s Advanced Membranes and Porous Materials Center told Phys.org that they also used the electrospinning process to convert the polymer into reusable and robust mats that can rapidly adsorb spilled oil, organic solvents, or fuel form the surface of salt or freshwater. Through electrospinning, it incorporated an extensive pore within the fibrous structure of the polymer and created a vast 565 square meters surface area per gram of the material.

The next step was to include water-repellent trifluoromethyl groups, which caused the polymer’s absorptive properties to reject the water while it continues to soak up the nonpolar liquids, like the oil floating on water. When the team tested their work, the material could efficiently and rapidly clean up the oil spills on water.

 

 

Adsorbing nonpolar solvent and rejecting water

In just a few minutes after they deployed the mats, they already adsorbed about 25 and 56 grams of oil or nonpolar solvent. Topuz added that the sorption performance of the mat is much better than other reported adsorbents introduced. What’s more ideal about the material is that it can be reused or recycled with the same performance as it was used for the first time. This demonstrates great potential for cleanup of nonpolar solvents and oil spills, the author said

After testing, the KAUST group then processes the materials further to develop fibrous sponges and membranes to preserve the high performance of the material while easily make them recoverable adsorbents. Topuz and colleagues are also developing adsorbent materials crated out of sustainably sourced polymers to expand the range of pollutants that it can capture. For example, they plan that the material can be used in capturing heavy metals and organic micropollutants from water.

Electrospinning of the 6FDA–TrMPD from the dimethylformamide (DMF) solution at a 10% concentration produced the ultrafine nanofibers. At lower concentrations, the researchers obtained beaded-fibers. Several oils were tested for the study, including gasoline, diesel, silicon oil, and crude oil.

The feasibility of the porous mat for soil spill clean up was shown by the treatment of crude oil and real seawater, the authors added.

Environmental significance

They believe that oil spills have caused significant damage not only to the marine ecosystem but also to human life. Such a disaster has sparked a great demand for innovative and high-efficiency sorbents that can thoroughly clean water resources.

According to the US, the Environmental Protection Agency (EPA) Reach IT, there are some measures that oil and gas companies use to minimize oil spills and gas leakages. One is that they have adapted leak detection technologies. Methane sensors, for instance, can detect methane leaks. Installing these sensors can help easily identify the source of the leak. Carbon dioxide sensors and carbon monoxide sensors are also in widespread use nowadays and the industry continues to develop sensors for other toxic gases.

Another measure implemented by oil and gas companies in the creation of industry-sponsored safety institutions. EPA said that effective control of oil spills needs massive investment and individual firms cannot sufficiently finance research on new methods. This is why companies within the same industry are pooling their resources. An example of this would be The Center for Offshore Safety funded by the US offshore oil and gas industry itself. The center facilitates cooperation between the external stakeholders, such as local communities and the government, and the industry in handling environmental pollution.

More firms have also set spill reduction targets to complement state regulations. The plans comprise the steps they need to take to attain their goals. The method for tackling oil spills likewise depends on various factors, including the amount of oil spilled, the type of oil, the weather conditions, and the location of the spill.

 

 

Global oil spill

Our World in Data, a scientific online publication that focuses on large global problems, records that between 1970 and 2016, approximately 5.73 million tons of oil were lost as a result of tanker incidents. A single large incident of an oil spill can be responsible for a huge share of all the oil spills in a given year, it added.

The International Tanker Owners Pollution Federation (ITOPF), which maintains a database of oil spills from tank vessels, recorded one large spill (more than 700 tonnes) and two medium spills (7- 700 tonnes). The large spill was due to a vessel collision in North America in May. On the other hand, both medium spills occurred in South Asia, one resulted from the partially sank vessel and the other from a collision.

ITOPF uses a geographical information system, where spills are shown on maps. It added that the most frequent causes of oil spills are groundings and allisions or collisions. However, since the proportion of groundings has already decreased over the decades, allisions or collisions are the current most frequent cause of oil spills. Government and industry efforts in improving safety and standards of operation now made it 99.99% safe to transport oil by sea.

Oil is the lifeblood of industrialized nations and it has become one of the world’s important sources of energy. Yet, the global oil industry obtains a heavy toll from the marine environment. KAUST’s oil-adsorbing mats show promise of reducing ecological damage in oil spill emergencies.