Search Results (50)

Evaluating the impact of pollutants on ecosystems and human health is crucial. To achieve this, a wide range of bioassays, using organisms of different trophic levels, are available. Extrapolating the results of these bioassays to real environmental conditions remains a major challenge. This study addresses this challenge by aiming to develop an algorithm capable of predicting the effect of environmental conditions on the impact of a toxicant, pentachlorophenol (PCP). Three abiotic factors were considered: pH, temperature, and conductivity. In the absence of the toxicant, the activity of Escherichia coli is influenced only by pH and temperature. However, exposed to PCP, the sensitivity of the bacteria was affected by these three factors. From these data, a predictive model was established to assess the intensity of the toxic effect induced by PCP. This model was validated using a validation dataset and demonstrated a strong correlation between the experimental and predicted values (r² ≈ 0.9). Thus, this approach enables the effective prediction of PCP’s effects by accounting for environmental variations. This proof of concept constitutes a potential alternative, complementary to conventional models like BLMs (focused on water chemistry for metals) and QSARs (linking structure to intrinsic toxicity), which often overlook the complexities of real-world environmental conditions. Full article

This study developed an analytical method to monitor pesticide residues in water, ensuring compliance with maximum limits and protecting human health. While the QuEChERS method is commonly used for food matrices, its application to aqueous samples has been limited. This research aims to extend its use to water matrices by optimizing and validating chromatographic conditions for detecting Ametryn using GC-MS. Calibration curves for both the solvent and matrix extracts demonstrated satisfactory linearity. Significant matrix effects were observed, influencing the signal intensity. Detection and quantification limits were determined, with a higher sensitivity in the matrix. Precision (RSD%) and accuracy (recovery tests) met acceptable standards. Although Ametryn was not detected in the real water samples, 2,4-Di-tert-butylphenol, a possible degradation byproduct of pentachlorophenol, was found. This study advances pesticide detection methods, addressing key factors like selectivity, linearity, and matrix effects, while providing insights into degradation byproduct detection and pesticide contamination in water sources. Full article

Composting is a common treatment for the high amounts of sewage sludge produced in wastewater treatment plants, and the product is used in agriculture. Composting reduces the levels of biodegradable organic pollutants, although other compounds present in wastewater and not eliminated previously by conventional physical–chemical and chemical treatments, such as polychorodibenzo-p-dioxins/furans (PCDD/Fs) and polychlorinated biphenyls (PCBs), have been found in the final compost at higher levels than those observed in the initial sludge. Their formation was studied during composting under unfavorable aeration conditions and paying attention to different stages of the process. Experiments were carried out in small vessels inside a controlled oven for three types of sewage sludge. Pentachlorophenol was previously added as a dioxin precursor. A clear formation of PCDD/Fs was found, especially during the maturation stage for two experiments. Mainly octachlorodibenzo-p-dioxin (OCDD) and 1234678-heptachlorodibenzo-p-dioxin (1234678-HpCDD) to a lesser extent were formed. OCDD levels in the final samples were around 10 times higher than those of the initial mixture after removing the concentration effect. No clear formation nor degradation of PCBs was observed. The toxicity values due to PCDD/Fs and PCBs found in the initial mixtures were 1.20–2.46 ng WHO-TEQ/kg, and those from the final samples were 2.30–7.86 ng WHO-TEQ/kg. Although the toxicity values are below the most restrictive limits found in Europe in this case, toxicity could increase considerably with the presence and concentration of other precursors. Compost from sewage sludge is an ecological product, but the operating conditions must be controlled to avoid PCDD/F formation and facilitate degradation of persistent organic pollutants. Full article

Pentachlorophenol (PCP) is a ubiquitous emerging persistent organic pollutant detected in the environment and foodstuffs. Despite the dietary intake of PCP being performed using surveillance data, the assessment does not consider the bioaccessibility and bioavailability of PCP. Pork, beef, pork liver, chicken and freshwater fish Ctenopharyngodon Idella-fortified by three levels of PCP were processed by RIVM and the Caco-2 cell model after steaming, boiling and pan-frying, and PCP in foods and digestive juices were detected using isotope dilution–UPLC-MS/MS. The culinary treatment and food matrix were significantly influenced (p < 0.05) in terms of the bioaccessibility and bioavailability of PCP. Pan-frying was a significant factor (p < 0.05) influencing the digestion and absorption of PCP in foods, with the following bioaccessibility: pork (81.37–90.36%), beef (72.09–83.63%), pork liver (69.11–78.07%), chicken (63.43–75.52%) and freshwater fish (60.27–72.14%). The bioavailability was as follows: pork (49.39–63.41%), beef (40.32–53.43%), pork liver (33.63–47.11%), chicken (30.63–40.83%) and freshwater fish (17.14–27.09%). Pork and beef with higher fat content were a key factor in facilitating the notable PCP bioaccessibility and bioavailability (p < 0.05). Further, the exposure of PCP to the population was significantly reduced by 42.70–98.46% after the consideration of bioaccessibility and bioavailability, with no potential health risk. It can improve the accuracy of risk assessment for PCP. Full article

Microplastics (MPs), chlorinated phenols (CPs), polycyclic aromatic hydrocarbons (PAHs) and halogenated benzenes (HBs) are pollutants that are widely present in freshwater systems. As alternatives to conventional plastics, bioplastics are receiving a lot of attention, but there are limited data on their impact on pollutant behavior. This work therefore investigated the impact of pH on the sorption of CPs, PAHs and HBs, as some of the toxic and highly persistent pollutants, on seven different plastics using kinetic and isotherm studies. The pH of the water matrix impacted the adsorption behavior of CPs on all selected MPs, with the highest degree of adsorption occurring at pH 7 for the majority of the selected CPs. The highest adsorption affinity of CPs on the MPs, at pH 7, was obtained for 4-chlorophenol and 2,4-dichlorophenol on powdered polyethylene standard (q_t = 221 μg/g), while the lowest was obtained for the adsorption of pentachlorophenol on polyethylene terephthalate (q_t = 25 μg/g). On the other hand, the pH value of the water matrix did not affect the adsorption of halogenated benzenes and PAHs on MPs. The pseudo-second-order rate model fit the adsorption kinetics data of all experiments. The results obtained for the adsorption of CPs on MPs indicated a lower sorption affinity of CPs with MPs at pH 4 and pH 10 compared to pH 7. The Langmuir isotherm, at pH 7, implied that 4-chlorophenol’s adsorption affinity was not significantly influenced by the type of MPs. On the other hand, at pH 7, the adsorption of 2,4-dichlorophenol, 2,4,6-trichlorophenol and pentachlorophenol varied greatly, with powdered MP types showing the highest affinity for CP adsorption. Furthermore, the obtained adsorption isotherm results imply that electrostatic attraction, hydrogen bonds, π-π interactions and van der Waals interactions, are an integral part of adsorption mechanisms of the CPs on the MPs. Full article

Pentachlorophenol (PCP) is a persistent organic pollutant usually present in the form of sodium salts (PCP-Na) that has been banned for many years, but it can still be detected in animal food. The present study established a method of detecting PCP-Na and its metabolites—tetrachlorocatechol (TCC), pentachlorophenol acetate (PCP-acetate), and pentachloroanisole (PCA)—in swine samples (pork, fat, liver, heart, lungs and kidney), simultaneously using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS) based on the modified QuEChERS pre-treatment method. The validation results exhibited a good sensitivity with limits of quantitation (LOQs) of 1 μg/kg–2 μg/kg. The recoveries of spiked samples were in the range of 60.5–119.9%, with a relative standard deviation (RSD) between replicates (n = 5) of between 0.70% and 12.06%. Full article

Pentachlorophenol (PCP) has attracted wide attention due to its high toxicity, persistence, and bioaccumulation. In this study, a sensitive UPLC-MS/MS method for the determination of PCP in seafood samples was developed and validated. The samples were ultrasonic extracted with acetonitrile containing 1% acetic acid-acetonitrile and followed by using a pass-through solid-phase extraction (SPE) cleanup on Captiva EMR-Lipid cartridges. The linearity of this method ranged from 1 to 1000 μg/L, with regression coefficients of >0.99. The detection limit and quantitation limit were 0.5 μg/kg and 1.0 μg/kg, respectively. The recoveries in different types of seafood samples ranged from 86.4% to 102.5%, and the intra-day and inter-day relative standard deviations (RSDs) were 3.7% to 11.2% and 2.9% to 12.1%, respectively (n = 6). Finally, the method has been successfully utilized for the screening of PCP in 760 seafood samples from Zhejiang Province. PCP was detected in 5.8% of all seafood samples, with the largest portion of detections found in shellfish, accounting for approximately 60% of the total. The average concentrations detected ranged from 1.08 to 21.49 μg/kg. The non-carcinogenic risk indices for adults and children who consume PCP ranged from 10⁻⁴ to 10⁻³ magnitudes. All of these indices stayed significantly below 1, implying that the health risk from PCP in marine organisms to humans is minimal. Full article

A diverse spectrum of organisms, such as fungi, bacteria, and actinomycetes, can degrade and transform organic matter, including wood, into valuable nutrients. A sustainable economy has the goal of efficiently using waste as raw materials, and in this optic, it uses biological preparations more and more often, supporting the decomposition of lignocellulosic waste. With reference to wood wastes, which are produced in a substantial amount by the forest and wood industry, one of the possibilities to biodegrade such lignocellulosic material is the composting process. In particular, microbiological inoculum containing dedicated fungi can contribute to the biodegradation of wood waste, as well as the biotransformation of substances from the protection of wood, such as pentachlorophenol (PCP), lindane (hexachlorobenzene) and polycyclic aromatic hydrocarbons (PAHs). The purpose of this research was to produce a literature review in terms of the selection of decay fungi that could potentially be used in toxic biotransformation unions. The findings of the literature review highlighted how fungi such as Bjerkandera adusta, Phanerochaete chrysosporium, and Trametes versicolor might be ingredients of biological consortia that can be effectively applied in composting wood waste containing substances such as pentachlorophenol, lindane, and polycyclic aromatic hydrocarbons (PAHs). Full article

Biological toxicity testing plays an essential role in identifying the possible negative effects induced by substances such as organic pollutants or heavy metals. As an alternative to conventional methods of toxicity detection, paper-based analytical device (PAD) offers advantages in terms of convenience, quick results, environmental friendliness, and cost-effectiveness. However, detecting the toxicity of both organic pollutants and heavy metals is challenging for a PAD. Here, we show the evaluation of biotoxicity testing for chlorophenols (pentachlorophenol, 2,4-dichlorophenol, and 4-chlorophenol) and heavy metals (Cu²⁺, Zn²⁺, and Pb²⁺) by a resazurin-integrated PAD. The results were achieved by observing the colourimetric response of bacteria (Enterococcus faecalis and Escherichia coli) to resazurin reduction on the PAD. The toxicity responses of E. faecalis-PAD and E. coli-PAD to chlorophenols and heavy metals can be read within 10 min and 40 min, respectively. Compared to the traditional growth inhibition experiments for toxicity measuring which takes at least 3 h, the resazurin-integrated PAD can recognize toxicity differences between studied chlorophenols and between studied heavy metals within 40 min. Full article

The incidence and mortality due to neoplastic diseases have shown an increasing tendency over the years. Based on GLOBOCAN 2020 published by the International Agency for Research on Cancer (IARC), leukemias are the thirteenth most commonly diagnosed cancer in the world, with 78.6% of leukemia cases diagnosed in countries with a very high or high Human Development Index (HDI). Carcinogenesis is a complex process initiated by a mutation in DNA that may be caused by chemical carcinogens present in polluted environments and human diet. The IARC has identified 122 human carcinogens, e.g., benzene, formaldehyde, pentachlorophenol, and 93 probable human carcinogens, e.g., styrene, diazinone. The aim of the following review is to present the chemical carcinogens involved or likely to be involved in the pathogenesis of leukemia and to summarize the latest reports on the possibility of detecting these compounds in the environment or food with the use of electrochemical sensors. Full article

Polychlorinated dibenzo-p-dioxins and dibenzofurans and polychlorinated biphenyls were measured in the surface sediments of Liangshui River, the second largest drainage river in Beijing, China. The sum concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans and polychlorinated biphenyls ranged from 3.5 to 3019 (mean value: 184) pg g⁻¹ dry weight and from 319 to 5949 (mean value: 1958) pg g⁻¹ dry weight, and the corresponding World Health Organization toxic equivalent quantity values were 0.0011–5.1 pg TEQ g⁻¹ dry weight and 0.0074–1.4 pg TEQ g⁻¹ dry weight, respectively. The spatial distributions of polychlorinated dibenzo-p-dioxins and dibenzofurans and polychlorinated biphenyls showed increasing trends from urban area and development area to suburb. Principal component analysis revealed that polychlorinated dibenzo-p-dioxins and dibenzofurans contamination in the sediments may originate from pentachlorophenol and sodium pentachlorophenate and municipal solid waste incineration. Regarding polychlorinated biphenyls, the steel industry, combustion processes and usage of some commercial polychlorinated biphenyl products were identified as the major sources. The emission from a former steel plant could be the main contributor to polychlorinated biphenyls in urban areas. The mean value of the total toxic equivalent quantities in the sediment samples exceeded the Canadian interim sediment quality guidelines. Long-term wastewater irrigation increases the load of sediment-bound pollutants in agricultural soil and may pose potential ecological risks to crops and human health. Full article

Construction of the tunable oxygen vacancies (OVs) is widely utilized to accelerate molecular oxygen activation for boosting photocatalytic performance. Herein, the in-situ introduction of OVs on Bi₂MoO₆ was accomplished using a calcination treatment in an H₂/Ar atmosphere. The introduced OVs can not only facilitate carrier separation, but also strengthen the exciton effect, which accelerates singlet oxygen generation through the energy transfer process. Superior carrier separation and abundant singlet oxygen played a crucial role in favoring photocatalytic NaPCP degradation. The optimal BMO-001-300 sample exhibited the fastest NaPCP degradation rate of 0.033 min⁻¹, about 3.8 times higher than that of the pristine Bi₂MoO₆. NaPCP was effectively degraded and mineralized mainly through dechlorination, dehydroxylation and benzene ring opening. The present work will shed light on the construction and roles of OVs in semiconductor-based photocatalysis and provide a novel insight into ROS-mediated photocatalytic degradation. Full article

This study aimed to elucidate the origin of extracellular electron mediating (EEM) functionality and redox-active center(s) in humic substances, where they are ubiquitously distributed. Here, we show the emergence of EEM functionality during the humification of rice straw in artificial soil (kaolin and sand) with a matric potential of −100 cm at 20 °C for one year. We used the dechlorination activity of an EEM material-dependent pentachlorophenol-dechlorinating anaerobic microbial consortium as an index of the EEM functionality. Although rice straw and its mixture with artificial soil did not initially have EEM functionality, it emerged after one month of humification and increased until six months after which the functionality was maintained for one year. Chemical and electrochemical characterizations demonstrated that the emergence and increase in EEM functionality were correlated with the degradation of rice straw, formation of quinone structures, a decrease in aromatic structures, an increase in nitrogenous and aliphatic structures, and specific electric capacitance during humification. The newly formed quinone structure was suggested as a potential redox-active center for the EEM functionality. These findings provide novel insights into the dynamic changes in EEM functionality during the humification of organic materials. Full article

The development of innovative technology for effective pollutant degradation is becoming more important as a result of major environmental issues. Here, ZnO nanoparticles were synthesized using facile and aqueous chemical growth routes. Analytical techniques such as scanning electron micrographs (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Zeta Seizer (ZS), and Zeta Potential were used to analyze the resultant nanoparticles (ZP). The ZnO reveals a nanocluster texture that has a medium scale of 27 nm and a surface charge (17 ± 3 mV) with a wurtzite phase and crystalline nature. Photo catalysts have a higher potential for the thermal disposal of chlorophenols pollutants due to their low cost and simple synthesis procedure. The as-prepared sample underwent photocatalysis for the simultaneous photo-degradation of PCP and TCP as a model dye under sunlight. The ZnO nanostructure exhibited an exceptional degradation of around 85–90% for PCP and TCP in the aqua liquid, with the lowest amount of catalyst dosage of 240–250 μg individually and simultaneously, over 3 min beneath the sun ray. The greater productivity of the ZnO nanostructure for natural deterioration during solar irradiation indicates that the aqueous chemical growth enables the creation of effective and affordable photocatalysts for the photodegradation of a variety of environmental contaminants. Full article

Microorganisms are one of the main factors in the deterioration of cultural heritage, in particular art paintings. The antiseptics currently used in painting have significant limitations due to insufficient effectiveness or increased toxicity and interaction with art materials. In this regard, the actual challenge is the search for novel materials that effectively work against microorganisms in the composition with painting materials and do not change their properties. Chitosan has pronounced antimicrobial properties but was not used previously as an antiseptic for paintings. In our study we developed a number of mock layers based on sturgeon glue, supplemented which chitosan (molecular weight 25 kDa or 45 kDa), standard antiseptics for paintings (positive controls) or without additives (negative control). According to Fourier transform infrared spectroscopy and atomic force microscopy, the addition of chitosan did not significantly affect the optical and surface properties of this material. The ability of chitosan to effectively protect paintings was shown after inoculation on the created mock-up layers of 10 fungi-destructors of tempera painting, previously isolated from cultural heritage of the of the 15–16th centuries in the State Tretyakov Gallery, on the created mock layers. Our study demonstrated the principled opportunity of using chitosan in the composition of painting materials to prevent biodeterioration for the first time. Full article