Water hyacinth as a green and sustainable material for carbon aerogel electrodes utilized in membrane capacitive deionization

Abstract Water hyacinth is a substantial and quick‐growing plant that can strongly invade and negatively affect the aquatic ecosystem, causing many problems to the water environment by consuming nutrients and oxygen from surface water. However, the hierarchical porous carbon derived from water hyacinth can be employed for the removal of oil spills, heavy metals, or wastewater nutrients. Recently, water‐hyacinth‐derived carbon aerogel has been utilized as electrode for the desalination of brackish water using membrane capacitive deionization (MCDI) technology. In this research, lignocellulose aerogels were synthesized from water hyacinth, which were then pyrolyzed to obtain carbon aerogel and then treated with KOH to acquire activated carbon aerogel, with the corresponding surface area of 51 and 100 m 2 g −1 . The desalination capacity of the MCDI device was also evaluated using a 200 ppm NaCl feed water solution with an applied potential of 1.2 V. A high salt adsorption capacity value of 14.69 mg g −1 was achieved after 3000 s. These results will lead a new research area of biomass and bio‐waste conversion to fabricate CDI‐utilized carbon aerogel electrodes.