Redox-active rGO-nZVI nanohybrid-catalyzed chain shortening of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS)

Managing and treating per‐ and polyfluoroalkyl substances (PFAS) in membrane concentrates

“…Decomposition of organic contaminants in soil and water systems has been successfully demonstrated using nanometals. Nanoscale zero-valent iron (nZVI) ( Masud et al, 2021 ) is one of the most promising nanometals with high reductive capacity (standard reduction potential, E o = –0.44 V ( Adusei-Gyamfi & Acha, 2016 ). Recently, PFAS decomposition was demonstrated in batch experiments using nZVI conjugated with oxidants such as hydrogen peroxide ( Parenky et al, 2020 ).…”

“…Recently, PFAS decomposition was demonstrated in batch experiments using nZVI conjugated with oxidants such as hydrogen peroxide ( Parenky et al, 2020 ). The reactivity of nZVI was further improved by employing graphene oxide (GO) as a solid support to prevent nZVI agglomeration during reductive PFAS decomposition in water ( Masud et al, 2021 ). The abovementioned approach was effective for accelerating PFAS decomposition kinetics (particularly for longer-chain PFAS) due to the presence of delocalized electrons on GO enhancing the contact/interaction between nZVI and PFAS ( Gu et al, 2018 ).…”

Long-Term Exposure and Effects of rGO–nZVI Nanohybrids and Their Parent Nanomaterials on Wastewater-Nitrifying Microbial Communities

“…When nZVI is impregnated onto a rGO support, nZVI exhibits higher redox reactivity by remaining well dispersed on 2D graphene sheets. In addition, rGO’s external surface area, high electron transport property, and high adsorption tendency toward emerging contaminants such as per- and polyfluoroalkyl substances synergistically enhance contaminant removal capacity of the resultant NH, making it a promising material for environmental remediation. , So far, the commercial application of rGO–nZVI NHs is very limited and currently undergoing extensive research. Thus, although the current commercial applications of rGO–nZVI NHs are limited, they are being studied as part of a safer-by-design research approach to ensure safe future applications in the environment.…”

“…Also, the different compositions of NHs were chosen to determine the effects of iron content on the interaction of these NHs with the microbial communities. The NH composition range was selected based on previous literature that reported similar composition ratios of rGO–nZVI NHs for environmental applications. ,− To accomplish this, five identical sequencing batch reactors (SBRs) were inoculated with municipal wastewater and dosed with NHs or their parent nanomaterials (and one undosed control). The reactors were then operated for six solid residence times (SRTs; ∼115 days), followed by short-term kinetic studies (24 h) to determine nitrogen conversion rates and transcriptional responses.…”

“…In addition, rGO's external surface area, high electron transport property, and high adsorption tendency toward emerging contaminants such as per-and polyfluoroalkyl substances 29 synergistically enhance contaminant removal capacity of the resultant NH, making it a promising material for environmental remediation. 19,30 So far, the commercial application of rGO−nZVI NHs is very limited and currently undergoing extensive research.…”