Electrons in Chemical Combat: The Power of Electricity
“Even in the face of adversity, the unity stands strong, a testament to the compassion and team spirit of a soldier’s army in battle against their enemies”.
In today’s environment, with the excessive use of chemicals in our daily lives, we are generating enemies day by day. The chemicals we use enter the wastewater we generate every day, and some may come back to our household taps. This is because the treatment our wastewater receives is not sufficient enough to remove all the harmful chemicals. Such chemicals fall into the category of recalcitrant chemicals ( which are difficult to degrade), or emerging chemicals (which are hazardous to humans and their standards in water are unregulated).
To address this issue, for over two decades, many scientists have utilized electricity as a medium to accelerate the removal of these chemicals from water.
Let’s understand how it works!
Imagine you have a stain on your shirt from some spilled juice. You might use a stain remover to break down the juice stain into something else that’s easier to wash away. A similar phenomenon happens in the case of water treatment. We add different chemicals that can transform the enemy chemical into less toxic form so that they can be removed easily.
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The irony of reducing chemicals is that it often involves producing more! Nevertheless, scientists have explored training water to generate these chemicals themselves, with some external help from electricity.
The electricity opens the door of electrons, which move at incredibly high speed (~2200 Km/s). Well, electrons don’t move! They act as an army which transfers the energy from one electron to another by different transitions. The entire process happens so quickly that it appears they are moving. This movement generates current.
For electricity to reach the water and subsequently affect the enemy chemicals, a surface is needed to transfer electrons to the chemicals present in the water. This surface is called an “electrode.” When electrons transfer enough energy or when sufficient voltage is applied, the water transforms into highly reactive species known as reactive oxygen species (ROS). These ROS exist for microseconds and are extremely reactive. They oxidize the harmful chemicals in the water, converting them into non-toxic carbon dioxide and water.
This entire process is scientifically known as the Advanced Oxidation Process (AOP), widely used to treat chemicals that are difficult to degrade via physiochemical processes.
The process not only helps in reducing excessive chemical loads but is also self-sustaining for treating water by generating oxidizing agents within the water itself. Because the generated species exist for such a short time, they do not chemically overwhelm the environment and can work in situ. The transformative potential of electricity underscores our commitment to overcoming challenges and ensuring a sustainable future for all.
“Through the currents of electricity, electrons bravely battle chemical foes with unwavering determination.”
