Electrochemical Regeneration of Highly Stable and Sustainable Cellulose/Graphene Adsorbent Saturated with Dissolved Organic Dye.

Electrochemical regeneration of adsorbents presents a cost-effective and environmentally friendly approach. Yet, its application to 3D structured adsorbents such as cellulose/graphene-based aerogels remains largely unexplored. This study introduces a method for producing these aerogels, highlighting their significant adsorption capacity for dissolved organic pollutants and resilience during electrochemical regeneration. By adjusting the ratio of hydrophobized cellulose nanofibers to graphene, the aerogels demonstrate a tunable adsorption capacity, ranging from 56 to 228 mg/g. Hydrophobization using oleic acid is vital for maintaining the aerogels' structural stability in water. Notably, the aerogels maintain structural integrity and efficiency over at least 18 electrochemical regeneration cycles, underscoring their potential for long-term environmental applications. The increase in adsorption capacity observed after regeneration cycles, approximately 10-20% by the fifth cycle, is attributed to electrochemical surface roughening and the creation of new adsorption sites. The tunability and durability of these aerogels offer a sustainable solution for adsorption with electrochemical regeneration technology.

Fire activity across Cretaceous/Paleogene transition: Evidence from pyrogenic biomarkers preserved in the Mahadeo-Cherrapunji section, Meghalaya, India.

Previous studies on high concentrations of polycyclic aromatic hydrocarbon (PAHs) present in the shallow-marine Um-Sohryngkew River (USR) Cretaceous/Paleogene Boundary (KPB) section suggested regional fire incidences and biotic stress on life. However, such observations at the USR site have not been confirmed so far anywhere else in the region, we, therefore, do not know whether the signal was local or regional. Thus, to find out charred organic markers associated with the shelf facies KPB outcrop (at a distance of over 5 km) of the Mahadeo-Cherrapunji road (MCR) section, PAHs were analyzed using gas chromatography-mass spectroscopy. Data show a notable rise in the PAHs and exhibit maximum abundance in the shaly KPB transition layer (in biozone P0) and the immediately underlying layer. The PAH excursions match well with the major incidences of the Deccan volcanic episodes and convergence of the Indian plate with the Eurasian and Burmese plates. These events were responsible for seawater disturbances and eustatic and depositional changes, including the retreat of the Tethys. The incidence of high amount of pyogenic PAHs unrelated to the total organic carbon content is suggestive of wind-blown or aquatic system transportation. A down-thrown shallow-marine facies of the Therriaghat block was responsible for an early accumulation of PAHs. However, the spike of perylene in the immediately underlying KPB transition layer is plausibly linked to the Chicxulub impact crater core. Anomalous concentrations of combustion-derived PAHs together with the high fragmentation and dissolution of the planktonic foraminifer shells show marine biodiversity and biotic distress. Significantly, the pyrogenic PAH excursions are restricted to either the KPB layer itself or strictly below or above it, indicating regional fire incidences and attendant KPB transition (66.016 ± 0.050 Ma).