Chinese scientists have announced that this special material could be the answer in the quest for a cheap and limitless energy source.
China has made a new breakthrough in its ambition to harness nuclear energy. Scientists in the country have developed a new material that can extract uranium – the primary heavy metal used as fuel for nuclear reactors, from seawater.
The research team from the Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT) under the Chinese Academy of Sciences has created a “cost-effective” material. They state that this material has “the ability to absorb uranium.”
Approximately 4.5 billion tons of uranium are floating in the world’s oceans.
This material works by allowing solids, gases, or dissolved liquids to adhere to its surface. The new material features tiny, hollow spherical particles called “SA-DNA hydrogel microspheres”, which have an organic structure, measuring about 2 mm in diameter and containing numerous tiny holes measured in micrometers.
The research team, led by engineer Fa Yun and researcher Liu Huizhou, published this project in the Chemical Engineering Journal earlier this month.
This material is created by combining sodium alginate – a readily available product extracted from seaweed or other sources, with functional DNA strands that can recognize and bind to uranium ions.
Uranium is an essential element for nuclear energy. Traditionally, this metal is mined from rocks. However, since uranium is considered a non-renewable energy source, scientists are seeking to extract an endless supply of uranium from the world’s oceans.
The Nuclear Energy Agency (NEA) estimates that there are approximately 4.5 billion tons of uranium floating in the world’s oceans in the form of dissolved uranyl ions. This figure is over 1,000 times larger than the amount of uranium found on land.
However, extracting these ions poses many challenges. Among these challenges is the extremely low concentration of uranium in Earth’s oceans, with 1 ton of seawater containing just 3.3 milligrams of uranium, alongside many other ion species also present in seawater. Extracting uranium from the ocean is akin to searching for 1 gram of salt in 300,000 liters of freshwater.
According to the researchers, among the methods being developed, adsorption is the most common technique because it is simple, cost-effective, efficient, and environmentally friendly.
The adsorbent material is a combination of DNA-containing enzymes, a specific type of DNA, and synthetic microspheres – a material derived from the ion exchange between sodium alginate and calcium ions. The enzymes act as a “detector” because they only operate when binding to specific metal ions. Subsequently, the microspheres with rapid adsorption motion come into play.
Researchers state that compared to the most promising existing adsorbent materials, China’s adsorbent demonstrates an “unprecedented” ability to selectively detect uranium ions, with efficiency over 43 times greater than vanadium ions.
Since the 1950s, countries have raced to make nuclear energy a limitless energy source by pursuing technology to extract uranium from seawater. While some progress has been made, turning laboratory projects into real-world applications remains a challenge.
Currently, China has 27 nuclear reactors under construction, the largest number in the world. However, the country’s uranium ore is of low quality, necessitating imports to operate its reactors.
