Journal of hazardous materials letters最新文献

Handling hot oil spillage, particularly from oil refineries, petrochemical industry and automobiles is challenging and there have been limited solutions to address the issue. Polyetherimide (PEI) electrospun fibrous membranes were developed in this study by leveraging PEI's high-temperature stability to serve as promising materials for hot oil sorption. The morphology of the membrane forming fibers varied from circular to dumbbell shaped, by judicious choice of solvents of varying boiling points, to study the effect of fiber morphology on oil sorption capacity. Crosslinking of PEI membranes was carried out using ethylenediamine (EDA) to impart structural integrity and resiliency to the membranes. The PEI membrane composed of dumbbell-shaped fibers demonstrated an oil-sorption capacity of 25.4 ±1.5 g/g for engine oil at 150°C within one hour, outperforming a commercial polypropylene (PP) nonwoven absorbent, which failed and collapsed under the same high-temperature conditions. Enhanced oil sorption in the dumbbell-shaped fibrous membrane was achieved due to its lower tortuosity, aligned inter-fiber channels, and higher capillary pressure. Usefulness and sorption capacity of PEI based electrospun membranes may further be explored for controlling the oil spillage through introduction of specific surface features and functionalization.

Multiple poly- and perfluoroalkyl substances (PFASs) are present in aqueous film-forming foams (AFFF) used for firefighting activities. Currently, no single analytical technique provides a complete accounting of total PFASs or total organofluorine content in AFFF-contaminated samples. To provide insight into the performance of existing methods, we compared ten previously described PFAS measurement techniques. In AFFF-amended tap water, US EPA Methods 533 and 1633, adsorbable organic fluorine with particle induced gamma emission spectroscopy (AOF-PIGE) and fluorine-19 nuclear magnetic resonance (¹⁹F NMR) provided similar estimates of total fluorine. The total oxidizable precursor (TOP) assay, suspect screening, and adsorbable organic fluorine with combustion ion chromatography (AOF-CIC) yielded estimates of total organic fluorine that were about two to three times higher than the other techniques. Proximate to AFFF sources, suspect screening and modified EPA Method 1633 yielded higher results, while the TOP assay results were between the other two sets of analyses. Further from sources, suspect screening, modified EPA Method 1633, and the TOP assay yielded similar results that were 4-fold higher than results from targeted quantification methods, such as EPA Method 1633. These results are consistent with expectations about PFAS behavior and inform the selection of analytical techniques used for PFAS contamination characterization efforts.

Per- and poly-fluoroalkyl substances (PFAS) have been widely used in various industrial applications due to their unique properties. This study aims to provide a comprehensive analysis of PFAS research trends using a novel approach combining text mining techniques and large-scale language models (LLMs). PFAS-related scientific literature published from 1980 to 2024 was gathered from Scopus, and KH Coder and Claude 3 were used to perform the analysis. The results showed a significant increase in research output and a clear shift in research topics over the past 40 years. Whereas in the past, the focus was on analytical methods, more recently, the emphasis has been on environmental fate, toxicity assessment, alternative compounds, and regulation. With Claude 3, research areas can now be identified without reviewing the results of expert text mining. Comparisons of AI-extracted trends with insights from traditional review articles showed strong agreement, confirming the effectiveness of this approach. These findings suggest the need for continued interdisciplinary research on PFAS such as the development of remediation strategies, elucidation of health effects, and evidence-based policymaking. This study showed the possibility of integrating text mining and LLM for a comprehensive analysis of research trends, which will accelerate future research and development strategies.

Ultraviolet radiation combined with free chlorine (UV/chlorine) is an attractive alternative to UV or chlorination alone for disinfection. However, ^•OH and Cl^• radicals from UV/chlorine have recently raised increasing concerns about the possible formation of chlorinated products. A significant quantity of alkyl halides was generated from aliphatic carboxylic acids in the UV/chlorine process, in contrast to the absence of any detectable alkyl halides during chlorination alone. During the UV/chlorine process, the formation of CH₃Cl, CH₃CH₂Cl and CH₃CH₂CH₂Cl were was observed from acetic acid, propionic acid and n-butyric acid, respectively. The maximum yield of CH₃Cl was up to 54.6 % when acetic acid was treated at a chlorine to precursors (Cl/P) ratio of 4.0. In addition to CH₃Cl, CH₂Cl₂ and CHCl₃ were also detected as the products of acetic acid. The presence of bromide ions resulted in a reduction in the yields of chloroalkanes, the formation of bromine byproducts, and an increase in the total amount of halocarbons. Hydroxyl radicals and chlorine radicals were identified as key reactants in the radical quenching experiments. The reactions described in this paper contribute to the understanding of the mechanism of halogenated byproduct formation during the UV/chlorine process.

Synopsis

The radicals resulting from UV/chlorine lead to the conversion of carboxylic acids into a significant amount of alkyl halides that would not be generated by chlorination alone.

In this study, Brevibacterium sp. strain CS2 was used to evaluate the mechanisms of arsenic interaction with the bacterium and its enzymatic and protein profiling under arsenic stress. The bacterium was capable to resist the arsenate 280 mM and arsenite 40 mM as per MIC. The whole genome, available on NCBI, was analyzed for genes associated with arsenic, which confirmed the genes for both arsenic oxidation (aioB) and arsenic reduction arsR, arsC, ACR3, and arsB. The sharpening and shifting of FTIR spectra in the ranges of 3278–2851 cm⁻¹ are due to hydroxyl and amide stretching. SEM analysis showed no significant changes in morphology in arsenic stress while EDX analysis proved the arsenite interaction by showing arsenic peaks in the graph. Both glutathione and non-protein thiol showed different responses in the absence and presence of arsenic stress. Protein bands such as 25, 30, 32, 37, 42, 48, and 100 kDa were expressed more in arsenic-treated samples as compared to the control one. The presence of arsenic oxidizing genes, the ability to resist arsenic, and the varied response of enzymes and proteins in arsenic stress make the bacterium a suitable agent for arsenic eradication from contaminated sites.

The prevalence of microplastics (MPs) in food items is of significant concern due to their potential to cause various human health issues when ingested. Milk and dairy products are widely consumed for their nutritional value and have been found to contain MPs, as evidenced by numerous research studies. This review paper examines the current contamination levels of MPs in dairy products and breast milk, as well as evaluates the environmental impact of the analytical methods used for MPs analysis. The highest contamination levels in dairy products and human breast milk have been found up to 2590 MPs/L. Hence policymakers should enforce stringent regulations to ensure food quality. Additionally, it has been noted that existing analytical methods for detecting MPs in dairy products often fail to adhere to the principles of green analytical chemistry, with many scorings below 0.58 on the AGREE scale. These findings emphasize the urgent necessity for the development of rapid and green analysis methods for detecting MPs in dairy products and breast milk.

Electrochemical chlorination is promising for direct potable reuse (DPR) with zero-chemical-input and was investigated in this study for its application potential in reverse osmosis (RO)-based and non-RO-based DPR processes. Treatment of the simulated reclaimed water from non-RO-based trains showed satisfactory chlorine evolution compared to that from the RO-based trains. Under an applied current of 100 mA, a desired free chlorine concentration of 2 mg Cl₂ L⁻¹ was obtained within a short reaction time of 3.5 s. Consistent chlorine evolution performance was achieved in continuous experiments for 500 cycles, and the effluent pH was within the range of potable water guidelines (6.5 – 8.5). Electrochemical chlorination showed competitive disinfection performance compared to conventional chemical chlorination (7 log inactivation of E. coli within 60 s) at a low energy demand of ∼ 0.05 kWh m⁻³. The results of this preliminary investigation encourage the further exploration of electrochemical chlorination for DPR through the use of noble-metal-free anodes, utilization of renewable energy sources, removing persistent organic contaminants, and examining the synergy with RO-based DPR.

Graphitic carbon nitride (g-C₃N₄) has garnered significant attention due to its low cost, ease of preparation, high chemical stability, and non-toxicity. Nevertheless, pristine g-C₃N₄ faces challenges in simultaneously achieving a broad absorption range, high stability, efficient charge separation, and strong redox capability, which hampers its practical applications. Recently, g-C₃N₄-based Z-scheme photocatalysts have emerged as research hotspots owing to their robust redox ability, effective charge carrier separation, and capacity to harness visible light for degradation of tetracyclines (TCs) in waters. This review delves into the fundamental photocatalysis, and application of g-C₃N₄-based Z-scheme photocatalysts for the degradation of TCs pollutants. The review concludes with final remarks and a concise discussion on the prospects of g-C₃N₄-based Z-scheme photocatalysts.

This study investigated the combination of UV persulfate (UV/PS) treatment of recycled water and deficit irrigation to minimize pharmaceutical and personal care products (PPCPs) accumulation and improve crop quality. Lettuce, carrot, and tomato, commonly consumed raw, were cultivated in a greenhouse using PPCPs spiked recycled water, UV/PS treated recycled water, and tap water control, under irrigation rates at 60 %, 80 % and 100 % of crop evapotranspiration (ET_C) rates. UV/PS removed ≥ 99 % of carbamazepine, diclofenac, and fluoxetine from spiked recycled water. Post-treatment, carbamazepine accumulation in harvested lettuce, carrot, and tomato was reduced by 96–99 %, 35–70 % and 72–93 %, respectively. Minimal accumulation of diclofenac and fluoxetine occurred in edible crops due to their existence as dissociated ions. Three edible crops exhibited distinct trends of PPCPs accumulation in response to irrigation rates. Lettuce exhibited a decreasing PPCPs accumulation with a reduced irrigation rate, which was attributed to slower transpiration. In contrast, carrot and tomato exhibited increased PPCP accumulation due to osmotic adjustment. Lettuce and carrot exhibited higher irrigation water utilization efficiency at deficit irrigation, while the opposite was observed for tomato. This study highlights the beneficial integration of UV/PS with deficit irrigation to conserve water, maintain crop yield, and minimize PPCPs accumulation.

Present study was performed with the aim to isolate Heavy metal Tolerant- PGPB (HMT-PGPB) from metal-contaminated site and use them for Cr bioremediation. Six different bacterial strains were obtained from the endosphere of Solanum virginicum L. roots and cultured using nutrient agar media amended with 20 mg/L of Cr(VI). The ability of these Cr(VI) tolerant bacterial isolates were assessed for PGP traits like producing siderophores, indole-3-acetic acid (IAA), and phosphate solubilization. The findings indicated that all of the isolates could produce exopolymeric substances and IAA, five of them could produce siderophores, and three could solubilize phosphate. Furthermore, the minimum inhibitory concentrations of these strains werealso determined. These strains were identified as Bacillus licheniformis SxR1, B. tequilensis SxR2, B. subtilis SxR3, B. velezensis SxR4, B. amyloliquefaciens SxR6, and B. stercoris SxR8. To validate the findings, it is crucial to comprehend how Cr(VI) affects Bacillus sp. SxR1 cells to determine the course of uptake and bacterial cell alteration, which was assessed via Fourier Transform-Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM).