Combining plug-in devices for reconfigurable removal of trichloroethylene and heavy metal ion in aqueous solution: Application and biosafety of iron-iron sulfide and its composites

The development of artificial intelligent (AI) planning for smart water treatment and the exploration of digitizable continuous-flow fabrication platform comprising electrically operable reactions for reconfigurable contaminant removal are two important challenges in future water purification technology. Most research and development efforts as well as the investment in water purifying materials have been focusing on the dimensions, compositions, or architectures containing highly adsorptive and catalytic components for effective combinatorial contaminant removal. However, limited attempts have been made to secure a digital system for adjusting the supply of existing adsorbents and chemicals to respond to transient or nonuniform distribution of contaminant load. To utilize AI planning in a more practical manner, developing a plug-in platform is necessary for reconfigurable fabrication that enables in situ supply of different water purifying materials. Therefore, a platform suitable for handling different material architectures was constructed by selecting different operation modes of plug-in reactionware (spark ablation, droplet generation, and photon supply) to modulate the architectures of water purifying materials. First, iron-iron sulfide (Fe-FeS) was fabricated using Fe nanoparticles and thiol vapors under photoirradiation, followed by combining the resulting Fe-FeS with metal (cobalt, nickel, or palladium) nanoparticles or graphene nanosheets to enhance the trichloroethylene (from 0.135 to 0.221 h(-1) in removal kinetics) or heavy metal ion (from 299 to 592 mg g(-1) in adsorption capacity) removal. Finally, in vitro toxicological analyses were conducted to determine biosafety of the resulting materials. The results of cell viability and reactive oxygen species profiles indicated that further investigation is required to realize the safe-by-design concept.