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As the world transitions towards a more sustainable future, it is imperative to develop innovative solutions that address the pressing issue of plastic pollution. Microplastics, in particular, have become a significant concern due to their widespread presence in the environment and potential to interact with toxic pollutants. Organic compounds, which include a variety of harmful chemicals, such as pesticides and other industrial chemicals, are often released into the environment and can readily bind to microplastics. In this context, understanding the adsorption of organic compounds on microplastics is crucial for designing effective strategies to mitigate their environmental impacts. This study investigates the adsorption dynamics of organochlorine pesticides (OCPs) on polystyrene microplastics, exploring the influence of pH and contact time, as well as utilizing kinetic models and isothermal equations to elucidate the adsorption mechanism. The results suggest that the pH level has a negligible impact on the adsorption capacity of PS for OCPs. In contrast, the contact time plays a significant role in the amount of OCPs adsorbed onto the PS surface. Interestingly, a relatively short time of up to 6 h was sufficient to reach equilibrium. The adsorption of OCPs on PS follows a uniform pattern consistent with the Freundlich isotherm model, indicating a multilayer adsorption process. The use of kinetic models to describe the adsorption process was also found to be useful in understanding its mechanism. Specifically, the pseudo-second-order kinetic model proved to be a suitable descriptor for the adsorption process of organochlorine pesticides on PS. This study highlights the importance of understanding the interactions between microplastics and organic pollutants, which is crucial for developing sustainable solutions to mitigate the environmental impacts of plastic pollution, ultimately contributing to a more environmentally conscious future. [ABSTRACT FROM AUTHOR]

A high-performance liquid chromatography with diode array detector (HPLC-DAD) analytical method was developed for the simultaneous detection of 17 phenolic compounds, including phenols, chlorophenols, alkylphenols, and nitrophenols, in two types of water matrices: wastewater and surface water. Prior to HPLC-DAD determination, a solid-phase extraction (SPE) procedure was optimized. The proposed method uses multiwavelength analysis, with the optimum detection wavelengths selected as 268 nm, 280 nm, 386 nm, 304 nm, and 316 nm. The highest resolution was achieved using a chromatographic column, Eclipse XDB-C18 (150 × 4.6 mm, 5 μm), which was kept at 20 °C. The mobile phase consisted of a gradient elution program, with mobile phase A being a 0.1% H3PO4 aqueous solution and mobile phase B being acetonitrile. The flow rate was set at 0.6 mL/min. The 17 target phenolic compounds were fully separated in less than 27 min. All compounds showed good linear regression, with correlation coefficients higher than 0.999. The method's quantitation limits ranged from 4.38 to 89.7 ng/L for surface water and 7.83 to 167 ng/L for wastewater. The recovery rates were in the range of 86.2–95.1% for surface water and 79.1–86.3% for wastewater. The SPE-HPLC-DAD method was proven to be fast, sensitive, accurate, and reproducible. The developed method was successfully applied for the analysis of the 17 phenolic compounds in real surface water and wastewater samples, with phenol, 2,4-DNP, and 2,4-DNP being determined at levels greater than the method's limits of quantitation (LOQs). The proposed analytical method represents an original technical resource for the simultaneous determination of 17 phenolic compounds in environmental water matrices. [ABSTRACT FROM AUTHOR]

Organic sun-blocking agents are recognized as emerging pollutants of the aquatic environment. The consequences and effects of these harmful substances on aquatic organisms are not fully understood, particularly in the context of Romania. This study examines the presence and environmental hazards posed by ten UV filters found in the Danube River. Six of the ten targeted contaminants were detected in surface water samples: 2-hydroxy-4-methoxy-benzophenone (BP-3), 2,4-dihydroxy benzophenone (BP-1), 2,3,4-trihydroxy benzophenone (234HBP), 2,2′-dihydroxy-4-methoxy-benzophenone (BP-8), 2-hydroxy-4-methoxy-4′-methyl-benzophenone (BP-10), and benzyl salicylate (BS). In sediment samples, seven of the ten compounds were identified: BS, BP-3, 4-hydroxybenzophenone (4HBP), BP-1, 234HBP, 2,2′,4,4′-tetrahydroxybenzophenone (BP-2), and BP-10, with different frequencies. The correlation coefficients showed strong relationships between benzophenone derivatives in surface water samples and a common contamination source for BP-3 and BS in sediment samples. In the assessment, the risk quotient (RQ) for BP-1 in fish was determined to be 1.81. Similarly, RQ values for BP-3 were calculated as 1.24 for Daphnia magna and 57 for fish, suggesting that these UV filters could potentially present substantial hazards to the aquatic ecosystem. The study findings indicate that additional research is needed to investigate the presence and potential risks of organic sun-blocking agents in surface waters, with a particular emphasis on densely populated areas in Romania. [ABSTRACT FROM AUTHOR]

Understanding the volatile flavor compounds present in commercial beverages is crucial for the food and beverage industries as these compounds significantly influence product perception and consumer acceptability. This paper aims to comprehensively analyze the composition of volatile organic compounds in various commercial beverages using targeted gas chromatographic–mass spectrometry (GC/MS) approaches. The study employs a screening method based on the Headspace-GC/MS technique to efficiently extract and identify volatile organic compounds found in commercial beverages. This methodology provides a rapid and reliable system for assessing the volatile profile of these beverages. The analysis reveals the presence of a total of 40 volatile organic compounds, including esters, terpenes/terpenoids, alkenes, aldehydes, aromatic hydrocarbons, and alcohols. Medium-chain esters were found to dominate the volatile profile of the beverages, suggesting a significant contribution to their fragrance and taste. This study offers valuable insights into the volatile profile of commercial beverages, creating awareness among consumers about the flavor components present in these products. By understanding the volatile composition, consumers can make informed choices regarding their beverage consumption. The comprehensive analysis provided by this research serves as a foundation for further studies related to flavor characterization and optimization in commercial beverages. [ABSTRACT FROM AUTHOR]

Organophosphate ester flame retardants (OPFRs) are ubiquitous organic pollutants in the environment and present an important preoccupation due to their potential toxicity to humans and biota. They can be found in various sources, including consumer products, building materials, transportation industry, electronic devices, textiles and clothing, and recycling and waste management. This paper presents the first survey of its kind in Romania, investigating the composition, distribution, possible sources, and environmental risks of OPFRs in five wastewater treatment plants (WWTPs) and the rivers receiving their effluents. Samples from WWTPs and surface waters were collected and subjected to extraction processes to determine the OPFRs using liquid chromatography with mass spectrometric detection. All the target OPFRs were found in all the matrices, with the average concentrations ranging from 0.6 to 1422 ng/L in wastewater, 0.88 to 1851 ng/g dry weight (d.w.) in sewage sludge, and 0.73 to 1036 ng/L in surface waters. The dominant compound in all the cases was tri(2-chloroisopropyl) phosphate (TCPP). This study observed that the wastewater treatment process was inefficient, with removal efficiencies below 50% for all five WWTPs. The environmental risk assessment indicated that almost all the targeted OPFRs pose a low risk, while TDCPP, TCPP, and TMPP could pose a moderate risk to certain aquatic species. These findings provide valuable information for international pollution research and enable the development of pollution control strategies. [ABSTRACT FROM AUTHOR]

Sunscreen compounds are one of the most toxic substances detected in the aqueous environment. However, these molecules are continuously utilized in a various range of products to provide protection against UV radiation. The removal of three sunscreen compounds, 4-hydroxybenzophenone (4-HBP), 2,4-dihydroxybenzophenone (BP-1) and oxybenzone (BP-3), by commercial activated carbon (AC) was investigated using batch adsorption experiments. Different operational characteristics, such as adsorbent dosing, interaction time, solution pH and starting sunscreen compound concentration, were studied. The adsorption capacity of the AC material was assessed using a liquid chromatograph associated with a mass spectrometer detector (LC–MS/MS). Two isotherm models were utilized to explained the target compound adsorption phenomenon (Langmuir and Freundlich), while pseudo-first and -second kinetic orders and thermodynamics were utilized to examine the adsorption mechanism. The maximum adsorption capacities determined from the Langmuir isotherms were established as 43.8 mg/g for 4-HBP, 48.8 mg/g for BP-3 and 41.1 mg/g for BP-1. The thermodynamic parameters revealed the following: a negative ΔG° (<20 KJ/mol) and ΔH° and a positive ΔS° of the targeted sunscreen compounds adsorbed onto AC suggest a spontaneous and exothermic adsorption process, favored by lower temperature, proving that the physical sorption mechanism prevailed. Effective adsorption of 4-HBP, BP-3 and BP-1 from real wastewater samples proved the viability of sunscreen compound removal using commercial AC material. This paper offers promising results on a sustainable, economical and environmentally friendly method for removal of ubiquitous sunscreen compounds from wastewater, as a possible enhancement of treatment processes. [ABSTRACT FROM AUTHOR]

Ultrasonic technology (US) can be considered a very sustainable and efficient method to remove bisphenol A (BPA) from water. Compared with other methods, the proposed method has some advantages: a simple implementation on existing water treatment and purification facilities, it does not generate residual compounds that produce sludge, a relatively fast time is required for degradation (1–2 h), and high degradation efficiencies. In this work, we present the results regarding BPA degradation efficiency using the ultrasonic technique. The influence of frequency and of some additional compounds, such as carbon tetrachloride (CCl4), FeSO4 7H2O (FS), and ethyl anthraquinone (EAC), were studied. Three different frequencies were used: 1146 kHz, 864 kHz, and 580 kHz, at 50 W. The sampling, performed every 15 min, revealed that the highest BPA degradation was achieved after 60 min. Using the liquid chromatography tandem mass spectrometry (LC-MS/MS) technique, the degradation compounds were identified. Pathways of BPA degradation were also proposed. The use of additives such as CCl4, FS, and EAC proved to have a positive effect on the BPA degradation process assisted by ultrasound. After 60 min of exposure, the degradation capacities reached values of between 50% and 75%, while the mineralization capacities were situated between 20% and 35%. CCl4 and EAC had a more pronounced stimulating action than FS, with the EAC having the highest mineralization capacity, representing around 75% of the degradation capacity. [ABSTRACT FROM AUTHOR]

The principal objective of the present research involved the achievement of high biodegradation degrees of perfluorooctanoic acid (PFOA) and perfluorosulfonic acid (PFOS) using pure individual bacterial strains. The use of such microorganisms can contribute to the improvement of the wastewater treatment process in sewage treatment plants through bioaugmentation or other bioremediation processes. Thus, in this study, we investigated the biodegradation potential of PFOA and PFOS. Bacterial strains tested in this study were from the Pseudomonas genus, namely: Pseudomonas aeruginosa and Pseudomonas putida, due to their known capacity to degrade xenobiotic compounds. The results indicated that Pseudomonas aeruginosa was able to transform 27.9% of PFOA and 47.3% of PFOS in 96 h, while Pseudomonas putida managed to transform 19.0% of PFOA and 46.9% of PFOS in the same time frame. During the biodegradation tests, PFHxA was recognized as the principal biotransformation product of PFOA in the presence of Pseudomonas aeruginosa, and PFPeA, PFPxA and PFHpA were recognized as the biotransformation products in the presence of Pseudomonas putida. For PFOS, only two biotransformation products (PHHxA and PFHpA) were observed as a consequence of biodegradation by both bacterial strains. [ABSTRACT FROM AUTHOR]

Photocatalytic degradation of carbamazepine (CBZ) from spiked aqueous solutions, via a UV/TiO2 system, was investigated, and the optimum photocatalyst type (P25 Degussa) and dose (500 mg/L), as well as irradiation time (45 min), were established. The degradation process kinetics was studied, and a degradation rate constant of 3.14 × 10−5 M min−1 was calculated for CBZ, using the Langmuir–Hinshelwood equation. Experiments performed in the presence of scavengers showed that the main reactive species involved in the degradation process are holes and free hydroxyl radicals; superoxide radicals also play a role in CBZ degradation. Eight transformation products of CBZ were identified, and a possible degradation pathway, consisting of four routes, was proposed. Toxicity and genotoxicity tests were also performed for both untreated and treated CBZ solutions, proving that the use of a UV/TiO2 system represents a suitable treatment approach for aqueous systems with CBZ content. [ABSTRACT FROM AUTHOR]