Surface Modification of Graphene Oxide for Fast Removal of Per- and Polyfluoroalkyl Substances (PFAS) Mixtures from River Water.

Per- and polyfluoroalkyl substances (PFAS) make up a diverse group of industrially derived organic chemicals that are of significant concern due to their detrimental effects on human health and ecosystems. Although other technologies are available for removing PFAS, adsorption remains a viable and effective method. Accordingly, the current study reported a novel type of graphene oxide (GO)-based adsorbent and tested their removal performance toward removing PFAS from water. Among the eight adsorbents tested, GO modified by a cationic surfactant, cetyltrimethylammonium chloride (CTAC), GO-CTAC was found to be the best, showing an almost 100% removal for all 11 PFAS tested. The adsorption kinetics were best described by the pseudo-second-order model, indicating rapid adsorption. The isotherm data were well supported by the Toth model, suggesting that PFAS adsorption onto GO-CTAC involved complex interactions. Detailed characterization using scanning electron microscopy-energy dispersive X-ray spectroscopy, Fourier transform infrared, thermogravimetric analysis, X-ray diffraction, and X-ray photoelectron spectroscopy confirmed the proposed adsorption mechanisms, including electrostatic and hydrophobic interactions. Interestingly, the performance of GO-CTAC was not influenced by the solution pH, ionic strength, or natural organic matter. Furthermore, the removal efficiency of PFAS at almost 100% in river water demonstrated that GO-CTAC could be a suitable adsorbent for capturing PFAS in real surface water.

Groundwater Suitability Evaluation Using Entropy Weightage Quality Index (EWQI) Model and Human Health Cancer Risk Assessment of Heavy Metal in Eastern India.

This study evaluated the groundwater using the Entropy Weightage Quality Index model (EWQI). Eighteen samples were taken from the different wellbores during premonsoon seasons in 2021. The present study is aimed at developing a comprehensive approach for groundwater quality assessment and associated health risk along with the cancer risk due to the presence of heavy metals. The water quality of Ranchi city was found to be better except in the western zone. Principal component analysis (PCA) revealed that arsenic (As) was the most influencing element that deteriorated the potability of water which supports our study. The study looked at cancer and noncancer health hazards connected with heavy metal music. The value of hazardous quotient (HQ) was observed to be relatively higher in As (HQ > 1) and Ni, followed by Mn > Fe > Zn > Cu. Also, the children were at higher risk than adults. The cancer risk associated with arsenic was investigated and found that the northern part and southeast-west (lapung block) of the study are at higher risk. Prolonged ingestion of As causes diseases like arsenicosis that leads to enhanced chances of cancer risk. This research provides an immense research database to assess the potability of drinking water in a similar city like Ranchi.

Exceptional adsorption of different spectral indices of natural organic matter (NOM) by using cerium oxide nanoparticles (CONPs).

In this study, the efficiency of cerium oxide nanoparticles (CONPs) was examined for the adsorptive removal of various spectral indices of Natural Organic Matter (NOM). Two methods, viz. efficient microwave combustion (ECM) and hydroxide mediated approach (HMA), were used to synthesize CONPs. The developed materials were characterized by the field emission scanning electron microscope (FESEM) with energy dispersive X-ray (EDX) and the Fourier transform infrared spectroscopy (FTIR). Moreover, the X-ray powder diffraction (XRD) confirmed the cubic structure with an average crystal size of 20.16 nm (CONP-I) and 6.75 nm (CONP-II). The observed point of zero (pHPZC) charge was approximately 7.0. The enhanced BET surface area (85.43 m2/g, 78.59 m2/g) and pore volume (0.007310 cm3/g, 0.006761 cm3/g) of CONPs support the higher adsorption. The effect of operational parameters (pH, contact time, and adsorbent dosage) and thermodynamical aspects of adsorption was also investigated. The Temkin isotherms described the experimental data better, with a maximum adsorption capacity of 238.9 mg/g (CONP-I) at neutral pH. Further, the experimental data can better be modeled by the pseudo-second-order kinetics (R2, 0.9851). Overall, CONPs possess great efficiency for the simultaneous removal of DOC (94%), UV254 (93%), adsorption slop index (ASI) (95%), phenolic content (88%), and carboxylic content (73%).