Removing water contaminants and cleaning water can be a long process. Even you can’t remove some pollutants like arsenic with this little effort.
The researchers have introduced a water purifier device that could even remove the most dangerous water pollutant arsenic. The device consists of polymer electrodes that purify water from arsenic by 90% in one step method. As compared to other methods, it uses 10 times less energy.
The entire research was published in the “Advanced Materials” journal. According to the researchers, Arsenic is found in nature and the natural water lakes, streams and other resources absorb arsenic when the water goes through the arsenic-containing rocks. It’s a highly toxic metal and currently, it is affecting more than 200 million people in 70 countries.
The study was directed in the supervision of Xiao Su, a chemical and biomolecular engineering professor at the University of Illinois. According to Xiao Su, all arsenic types are not toxic. Only the arsenite is the most dangerous form of arsenic. It damages the biological tissues. If we apply a simple oxidation reaction to arsenite, we can convert it to arsenate that is less dangerous and less toxic. Some absorbents with particular membranes and thin evaporation can remove arsenite from water. But using these absorbents can be a highly energy-intensive process. Moreover, these processes leave lots of toxic material behind.
Xiao Su further explained that this issue could be resolved by using a device that could only capture arsenite from water and convert it into arsenate, the less toxic form. In this way, the toxicity of water could be reduced while cleaning it. So, his team invented polymer electrodes to capture arsenite from water and convert into arsenate without consuming lots of energy.
How Do Polymer Electrodes Work?
A pair of polymers are attached to a unit that’s similar to a battery and it’s called an electrocatalytic cell. When the water goes through the device, the first polymer electrode starts capturing the arsenite from water and transfers arsenite to the second polymer electrode. The second electrode reduces a pair of electrons from arsenite to convert it into arsenate. So, the pure water moves one out of the device.
An electrochemical reaction powers this process and polymer electrodes don’t consume lots of energy. The process of separation of arsenite from water and removing a pair of electrons to convert is into arsenate is called “process intensification. It’s an eco-friendly process due to less energy consumption.
Comparing this electrochemical approach with field deployment methods, the former can be more sustainable and energy-efficient. It could even work in backward countries like Bangladesh where more than 60% of people are drinking arsenic-contaminated water. The people living in rural areas can use solar panels to run this device.
According to Xiao Su, the electrodes are efficient, but we need to enhance its stability to meet the challenges faced by the world. Currently, they need to repeat the process many times. Although they have used highly advanced polymer materials in electrodes they should make it more stable. So, the users don’t need to replace electrodes time and again. That’s why; they need some more chemical development.