Electrochemistry plays a crucial role in tackling environmental challenges. From water treatment to pollution control, it offers innovative solutions for purifying water, degrading pollutants, and remediating contaminated soils. These applications harness the power of electrochemical reactions to create cleaner, safer environments.

Beyond cleanup, electrochemistry is revolutionizing energy storage and environmental monitoring. Redox flow batteries and fuel cells provide sustainable energy solutions, while electrochemical sensors enable real-time detection of pollutants and pathogens. These advancements are shaping a greener future.

Environmental Applications of Electrochemistry

Electrochemistry in water treatment

• Electrocoagulation destabilizes and removes contaminants by applying electric current to water, generating coagulants in-situ through the dissolution of sacrificial electrodes (iron or aluminum), effectively removing suspended solids, heavy metals, and organic pollutants
• Electrochemical disinfection uses electrolysis to generate oxidizing agents (chlorine, hydrogen peroxide) that inactivate pathogens, providing an alternative to chemical disinfectants with precise control over the dosage
• Capacitive deionization (CDI) removes dissolved ions from water using electrically charged electrodes, adsorbing ions onto the surface of porous carbon electrodes, regenerating electrodes by reversing the polarity to release the adsorbed ions, enabling the recovery of valuable minerals and salts (sodium chloride, potassium chloride)

Role in pollution control

• Electrochemical oxidation degrades organic pollutants through direct or indirect oxidation processes, generating highly reactive species (hydroxyl radicals) at the anode surface, applicable to the treatment of industrial wastewater, landfill leachate, and persistent organic pollutants (PCBs, dioxins)
• Electrochemical reduction converts toxic metal ions to less soluble or less toxic forms, reducing hexavalent chromium (Cr(VI)) to trivalent chromium (Cr(III)) and removing nitrates and nitrites from contaminated water
• Electrokinetic remediation applies electric fields to contaminated soils to mobilize and extract pollutants, transporting them towards electrodes by electromigration and electroosmosis, effectively removing heavy metals (lead, cadmium), organic contaminants (PAHs), and radionuclides (uranium, plutonium) from soils and sediments

Potential for energy storage

• Redox flow batteries store energy in the form of chemical energy in two separate electrolyte solutions, utilizing reversible redox reactions to charge and discharge the battery, offering scalability, long cycle life, and decoupled power and energy capacity (vanadium redox flow battery)
• Hydrogen production through water electrolysis splits water into hydrogen and oxygen using electricity, producing clean and renewable hydrogen fuel, enabling the storage of excess renewable energy (solar, wind) as hydrogen for later use in fuel cells or combustion engines
• Fuel cells convert chemical energy directly into electrical energy, utilizing hydrogen or other fuels (methanol, ethanol) to generate electricity with high efficiency and low environmental impact, finding applications in stationary power generation (residential, commercial) and transportation (fuel cell vehicles)

Applications in environmental monitoring

• Electrochemical sensors detect and quantify specific analytes in the environment, utilizing electrochemical principles (potentiometry, amperometry, voltammetry), offering high sensitivity, selectivity, and real-time monitoring capabilities for pH, dissolved oxygen, and heavy metals (lead, cadmium, mercury)
• Biosensors combine biological recognition elements (enzymes, antibodies) with electrochemical transducers to detect specific biological or chemical analytes in environmental samples, enabling the monitoring of pollutants (pesticides, herbicides), pathogens (E. coli, Salmonella), and biomarkers (toxins, hormones)
• Remote electrochemical sensing integrates electrochemical sensors with wireless communication technologies, allowing for continuous and real-time monitoring of environmental parameters, enabling the deployment of sensor networks in remote or inaccessible locations (wetlands, oceans), facilitating data collection, transmission, and analysis for environmental management and decision-making