Journal of hazardous materials letters最新文献

To assess the performance of hazardous waste sites remediation technologies like in situ chemical oxidation (ISCO) with persulfate (S₂O₈²⁻) researchers must periodically measure concentrations of target contaminants. Due to the presence of relatively high concentrations of the residual oxidant expected in many samples, the standard analytical method requires the addition of a relatively high concentration of ascorbic acid to prevent the oxidation process from continuing after sample collection. We discovered that addition of ascorbic acid quencher results in a radical chain reaction that transforms two common halogenated solvents (i.e., tetrachloroethene and hexachloroethane). To avoid the artifact associated with the radical chain reaction, a small quantity of n-hexane can be added to aqueous samples to extract target compounds and protect them from the radical chain reaction initiated by addition of the quencher. We recommend the use of this alternative sample preservation method whenever high concentrations of residual S₂O₈²⁻ are expected to be present in water samples that are contaminated with halogenated solvents.

With growing desire to destroy per- and poly-fluoroalkyl substances (PFAS) now known to be detrimental to human health, a sound understanding of fluorocarbon combustion chemistry is important to efficient thermal destruction within incinerators. While most fluorocarbon combustion models and the sets of reactions contained within them were originally developed for the high temperatures encountered in flame suppression applications, they have often been used to assess PFAS destruction in incinerators, which emphasize a lower range of temperatures. We present results that demonstrate that low-temperature fluorocarbon oxidation pathways—not yet known to play a role in fluorocarbon combustion—impact key incinerator performance metrics, including: PFAS surrogate mole fractions, products of incomplete destruction, and waste destruction efficiencies. The results further point to the utility of NO as a potential additive. The present results show the influence of these pathways for CF₃O₂, for which some data are available, but analogous pathways would also occur for other fluoroalkylperoxy radicals, for which little is known. The results demonstrate the need for future work to identify and characterize low-temperature pathways more generally, consider such pathways in kinetic model development, and experimentally probe intermediate temperature conditions to better understand, design, and control thermal destruction technologies for improved PFAS management.

Plastic waste accumulation is a significant environmental concern as it promotes microbial growth and acts as a carrier for heavy metals. This study focuses on a Bacillus sp. strain isolated from the surface of a used plastic bottle, tolerant to various potential toxic elements (PTEs) such as chromium, nickel, cobalt, copper, zinc, arsenite [As(III)], but sensitive to uranium (U) and arsenate [As(V)] toxicity. The strain demonstrates growth under different abiotic stress conditions, with the optimal pH range of 5.0–8.0 and a temperature of 30 °C. It shows remarkable removal capabilities, removing > 23.3% of U, > 38% of As(III)), and > 22.6% of As(V) from an initial dose of 100 mg L⁻¹ in an aqueous solution. The biosorption capacity for U, As(III), and As(V) is 3.12, 3.1, and 1.8 mg g⁻¹ of biomass, respectively. Kinetic modelling suggests that the biosorption of U and As(V) follows a pseudo-second-order mechanism, while As(III) biosorption follows a pseudo-first-order mechanism. Moreover, the strain has the ability to precipitate > 38.1% and ∼67% of U using bacterially released phosphate from inorganic and organic sources, respectively. These findings highlight the strain's potential for bioremediation of PTE-contaminated environments, providing valuable insights for optimizing metal removal and immobilization processes in future research.

Heavy metal pollution is consistently a critical issue in many parts of the world, affecting living systems remarkably. Many microorganisms possess such toxic metals utilizing capacities that can be explored for remediation. The present study demonstrates a comparative analysis of Mercury (Hg), Lead (Pb), Cobalt (Co), Zinc (Zn), and Magnesium (Mg) resistance genes in genomes of 11 different Georgenia sps. and confirmation of this gene pool in Georgenia sp. SUBG003 by growth on HgCl_2, CdCl_2, CoCl_2, and ZnCl₂ with varying concentrations and periods of up to 144hrs in a liquid medium and on a solid medium. Over a period HgCl₂ initial concentrations 0.01 mM, 0.03 mM, and 0.05 mM showed controlled growth, at interim concentrations of 0.07 mM, 0.09 mM were found to be an interim effect while 0.11 mM, 0.13 mM and 0.15 mM higher concentrations showed increased growth. While CdCl_2, CoCl_2, and ZnCl₂ showed growth inhibition upon increasing concentration from 0.01 mM to 0.5 mM. The concentrations tested are in a higher range than the polluted sources observed and the probable role in remediation is discussed.

Organochlorine pesticides have been widely used in agriculture to control agricultural pests. Although effective in controlling pests, organochlorine pesticides present numerous hazards to ecosystems and human health due to their persistence in the environment, bioaccumulation, and toxicity. Scientific studies have shown that organochlorines may be associated with endocrine and neurological problems. Several strategies have been developed to apply treatment techniques to remove pesticides from various ecosystems, both aquatic and terrestrial. Physicochemical and biological methods have revealed other potentialities for remediation of aqueous environments contaminated with organochlorine pesticides. In addition, combined processes using different approaches have been highlighted as efficient alternatives to mitigate the impacts of agrochemicals on the environment, e.g., physical technique followed by a biological process. However, there are still numerous gaps that need to be explored and elucidated. Therefore, this review addressed the impacts of organochlorine pesticides on ecosystems and some treatment techniques used to remove agrochemicals from water. Furthermore, new findings, technological perspectives, and opportunities on this subject were presented and discussed.

Since 2007, the market for e-cigarettes has resulted in increasing demand for newer technologies and flavorings contributing to the complexity of these products. As a result, methodologies for e-cigarette aerosol capturing and testing have become a necessity in understanding the toxicities surrounding e-cigarette products. This study tests an alternative aerosol capture method followed by toxicity testing of the sample collected on a lung in vitro model.

Per- and polyfluoroalkyl substances (PFAS) have been used in paper products since the 1960s. PFAS emissions during the life cycle of these products have been substantial sources of these substances to the environment. Here, a total of 37 PFAS were analysed in 13 paper products sampled in 2021, for which some were made of virgin paper and others recycled paper, including food contact materials (FCM), packaging, and a notebook. In addition, different fractions of the recycling process of corrugated paper and board were sampled at a Norwegian cardboard recycling plant and analysed for the same PFAS, to get an overview of PFAS in the recycling stream of these materials in Norway. PFAS were found in recycled paper and board, indicating PFAS can be a non-intentionally added substance (NIAS) in recycled paper products. Sum of targeted PFAS detected in paper products (including products made of virgin and recycled materials) ranged between 0.4 and 971 µg kg⁻¹, dominated by SAmPAP diester and 6:2 FTS (0–62% and 0–98%, respectively). The sum of targeted PFAS in returned corrugated paper and board in Norway is at least 32 kg per year (6 mg per capita per year). Recycling is important to ensure sustainability. As part of the broad PFAS restriction in Europe, PFAS are to be restricted in paper and board materials. Thus, lower levels of PFAS entering the recycling stream are expected in the future. Monitoring is necessary to assess reductions of PFAS in the paper waste stream due to PFAS regulations in Europe.

Polyquaternium polymers are widely used in various applications, such as personal care products and wastewater treatment plants, and eventually end up in the aquatic environment. While polymers have been perceived of low toxicological concern due to their size, several studies have pointed towards water-soluble cationic polymers being toxic towards aquatic organisms – and that the toxicity largely is determined by the polymer charge density. The present study investigated the polyquaternium toxicological mechanism of action throughout lipidomic analysis and changes in immune-gene expression (qPCR) of zebrafish larvae exposed continuously to two water-soluble polymers; a high charge density polyquaternium-6 and a low charge density polyquaternium-10, for 5 and 12 days upon fertilization. The results showed that the investigated polyquaterniums cause both inflammatory responses and significant alterations of the zebrafish larvae lipidome. Depending on polyquaternium polymer and larvae development stage, the gene expression showed an inflammatory response (e.g. significant up-regulation of il8, il1β and tnfα) in the exposed zebrafish. Alterations of the lipidome were additionally observed, with severe depletion of lipids (e.g. lyso-glycerophosphocholines and ceramides) in the 12 days old larvae exposed to high charge density polymer. The findings furthermore support a hypothetical mechanism of action to be non-specific and lethality potentially to be narcosis-like driven.

Water borne emerging pollutants represents a significant challenge confronting the modern society. As a result of excessive use of dyes and pigments by the textile and other industries, substantial amount of these toxic and recalcitrant substances are widely dispersed into the aquatic sources that may raise serious health issues to all life forms besides causing potential disruption to the ecosystem. Treatments of these hazardous and non-biodegradable organic contaminants in wastewater effluents have become a focal point for researchers dedicated to environmental remediation. Notably, Metal organic frameworks (MOFs) and their composites have been reported to be promising materials for tackling such challenges. This review is dedicated to provide a concise overview by consolidating the diverse beneficial attributes of Cu-BTC MOF rendering it as a versatile material with applications spanning diverse domains, focusing on the reactivity, the role of the metal ion and its recent potential for addressing the elimination of toxic textile dye wastes from the wastewater effluent. Furthermore, it also documents the underlying mechanistic pathway governing the degradation mechanism and the superior electron transport property of Cu ̶ BTC, besides painting in detail the existing limitations that hinder their applicability at an industrial platform. Moreover, a set of future research outlooks serving as a roadmap for exploring the potentiality of Cu ̶ BTC MOFs have also been presented.

Arsenic is a trace element and a metalloid which is prominently known as an environmental hazard. At present, rising health apprehensions are linked to emanating from a wide array of industrial, chemical, residential, agricultural, and technological sources, leading to extensive pollution of water, soil, and air ecosystems including flora, fauna and humans. It poses significant harm to biological organisms upon acute and chronic exposure. In this review, we delve into the reported experimental data that elaborates on arsenic as a toxicant, with particular emphasis on its occurrence, metabolism and diverse molecular mechanisms involved. It also includes the major molecular mechanisms leading to systemic toxicity with special emphasis on shedding light on the intricate ways it disrupts the nervous system.