Search Results (169)

The electrooxidation (EO) of three important environmental contaminants, anticorrosive 1H-benzotriazole (BTA), plasticizer dibutyl phthalate (DBP), and non-ionic surfactant Triton X-100 (tert-octylphenoxy[poly(ethoxy)] ethanol, t-OPPE), was studied as a possible means to improve their elimination from wastewaters, which are an important emission source. EO was performed in a batch reactor with a boron-doped diamond (BDD) anode and a stainless steel cathode. Different supporting electrolytes were tested: NaCl, H₂SO₄, and Na₂SO₄. Results were analysed from the point of their efficacy in terms of degradation rate, kinetics, energy consumption, and transformation products. The highest degradation rate, shortest half-life, and lowest energy consumption was observed in the electrolyte H₂SO₄, followed by Na₂SO₄ with only slightly less favourable characteristics. In both cases, degradation was probably due to the formation of persulphate or sulphate radicals. Transformation products (TPs) were studied mainly in the sulphate media and several oxidation products were identified with all three contaminants, while some evidence of progressive degradation, e.g., ring-opening products, was observed only with t-OPPE. The possible reasons for the lack of further degradation in BTA and DBP are too short of an EO treatment time and perhaps a lack of detection due to unsuitable analytical methods for more polar TPs. Results demonstrate that BDD-based EO is a robust method for the efficient removal of structurally diverse organic contaminants, making it a promising candidate for advanced water treatment technologies. Full article

The widespread discharge of industrial and urban waste has led to significant increases in the environmental concentrations of numerous chemical substances. This work presents the development of a simple and environmentally friendly dispersive liquid–liquid microextraction (DLLME) method based on a hydrophobic natural deep eutectic solvent (NADES) for the determination of selected compounds from benzotriazole, benzothiazole, paraben, and UV filter families in wastewater samples. Of the twelve NADES formulations evaluated, those composed of a 4:1 molar ratio of thymol and menthol presented the highest extraction efficiencies. The influence of key experimental variables such as the pH of the aqueous sample, the ratio of NADES phase to sample volume, and the extraction time on the extraction efficiency was investigated using a multivariate optimization. Under optimal conditions, relative standard deviations below 15% and recoveries for spiked wastewater samples ranged between 82 and 108%, demonstrating the suitability of the method for routine water-quality monitoring. The sustainability and practicality of the developed method was evaluated using the assessment tools ChlorTox, AGREEprep, AGRRE, and BAGI, obtaining scores of 0.005 g in the NADES-DLLME method, 0.70, 0.52, and 72.5, respectively, demonstrating that the method is green and reliable. Full article

To ensure the inherent safety of fine chemical nitration processes, the nitration reaction of benzotriazole ketone was selected as the research object. The thermal decomposition and reaction characteristics of the nitration system were studied using a combination of differential scanning calorimetry (DSC), reaction calorimetry (RC1), and accelerating rate calorimetry (ARC). The results showed that the nitration product released 455.77 kJ/kg of heat upon decomposition, significantly higher than the 306.86 kJ/kg of the original material, indicating increased thermal risk. Through process hazard analysis based on GB/T 42300-2022, key parameters such as the temperature at which the time to maximum rate is 24 h under adiabatic conditions (T_D24), maximum temperature of the synthesis reaction (MTSR), and maximum temperature for technical reason (MTT) were determined, and the reaction was classified as hazard level 5, suggesting a high risk of runaway and secondary explosion. Process intensification strategies were then proposed and verified by dynamic calorimetry: the adiabatic temperature increase (ΔT_ad) was reduced from 86.70 °C in the semi-batch reactor to 19.95 °C in the optimized continuous process, effectively improving thermal safety. These findings provide a reliable reference for the quantitative risk evaluation and safe design of nitration processes in fine chemical manufacturing. Full article

This study developed cholesteric liquid crystal broadband reflective films using zinc oxide nanoparticles (ZnO NPs) and homotriazine UV-absorbing dye (UV-1577) to enhance infrared shielding. Unlike benzotriazole-based UV absorber UV-327, which suffers from volatility and contamination, UV-1577 exhibits superior compatibility with liquid crystals, higher UV absorption efficiency, and enhanced processing stability due to its larger molecular structure. By synergizing UV-1577 with ZnO NPs, we achieved a gradient UV intensity distribution across the film thickness, inducing a pitch gradient that broadened the reflection bandwidth to 915 nm and surpassing the performance of previous systems using UV-327/ZnO NPs (<900 nm). We conducted a detailed examination of the factors influencing the reflective bandwidth. These included the UV-1577/ZnO NP ratio, the concentrations of the polymerizable monomer (RM257) and chiral dopant (R5011), along with polymerization temperature, UV irradiation intensity, and irradiation time. The resultant films demonstrated efficient ultraviolet shielding via the UV-1577/ZnO NPs collaboration and infrared shielding through the induced pitch gradient. This work presents a scalable strategy for energy-saving smart windows. Full article

Relatively little data exist regarding the presence of unregulated contaminants in drinking waters. We sampled source and finished drinking water from 98 community water supply systems throughout Minnesota (U.S.). Facilities were grouped into four networks based on water source and influences from anthropogenic activities. Measured contaminants were dependent on network and included some combination of pesticides, pharmaceuticals, per- and poly-fluoroalkyl substances (PFAS), benzotriazoles, hormones, wastewater indicators, and illicit drugs. Overall, the number of contaminants detected in samples ranged from 0 to 35 and concentrations ranged from 0.38 ng/L (progesterone) to 47,500 ng/L (bromoform). Fewer contaminants and lower concentrations were detected in finished water samples, compared to source waters. Significantly (p < 0.05) more PFAS and pesticides and higher sample total concentrations were observed in wells designated as vulnerable to contamination. To estimate potential human-health risk from exposure in drinking water, concentrations were compared against bioactivity information from the U.S. Environmental Protection Agency’s ToxCast database and state-based guidance values, when available. Although comparisons could be made for relatively few contaminants, concentrations in finished waters were at least an order of magnitude lower than screening thresholds. Results from this study were used to inform enhancement of the Minnesota Department of Health’s drinking water protection program. Full article

Removal of micropollutants using biological treatment systems remains a challenge, since conventional bioprocess systems require adaptations to provide more advanced treatment. An ambient temperature upflow anaerobic sludge blanket (UASB) reactor was employed, followed by a two-stage (saturated and unsaturated) vertical subsurface flow (VSSF) constructed wetland (CW) system, to treat domestic wastewater from a nearby settlement and investigate the occurrence and fate of 10 contaminants of emerging concern (CECs) in decentralized, non-conventional treatment systems. The integrated UASB—two-stage CW system achieved high performance regarding abatement of target CECs across all periods. Removal efficiencies ranged from 78% ± 21% (ketoprofen) to practically 100% (2-hydroxybenzothiazole). The pilot system was found to be robust performance-wise and provided enhanced treatment in comparison to a conventional wastewater treatment plant operating in parallel. Most of the target CECs were successfully treated by UASB, saturated and unsaturated CWs, while ibuprofen, bisphenol A and diclofenac were mostly removed in the unsaturated CW. Environmental risk assessment revealed that triclosan poses a significant ecological risk to algae during treated wastewater disposal into the aquatic environment. Additionally, cumulative risk quotient indicated that the potential for mixture toxicity should be carefully considered across all trophic levels. Full article

Efficient thermal management is critical to the performance and acceptance of battery electric vehicles (BEVs). In the event of coolant leakage, contact between conventional water–glycol coolants and polarized battery components may induce hydrogen evolution via electrolysis, posing a serious safety hazard. This study investigates the impact of copper corrosion inhibitors and coolant electrical conductivity on hydrogen gas formation through linear sweep voltammetry (LSV) using copper electrodes. Results indicate that commonly used corrosion inhibitors—Tolyltriazole (TTZ), Benzotriazole (BTZ), and Sodium Mercaptobenzothiazole (MBT-Na)—do not significantly reduce hydrogen evolution, even in synergistic combinations. On the other hand, lowering the coolant electrical conductivity markedly decreased hydrogen evolution, with a linear reduction in cathodic current observed in low-conductivity coolants due to the reduced ionic mobility of the electrolyte. Low-conductivity BEV coolant (86 µS/cm) presented a cathodic current density 96% lower than a high-conductivity ICE coolant (2577 µS/cm) at the same overpotential. These findings suggest that optimizing coolant conductivity is a more effective mitigation strategy than relying on corrosion inhibitor formulations. Full article

Contaminants of emerging concern (CECs) comprise a diverse group of substances whose presence in the environment is of increasing concern due to their potential negative effects on human health and the environment. Multiple studies have concluded that nanofiltration (NF) and reverse osmosis (RO) membrane separation mechanisms are effective barriers for organic pollutants, showing generally high removal efficiency. In this study, nine indicator CECs included in the Directive (EU) 2024/3019 concerning urban wastewater treatment were selected and used as a reference to calculate the removal percentage of all micropollutants present in the influent of wastewater treatment plants (WWTPs). According to the regulations, a minimum average removal percentage of 80% of the influent load must be achieved by analyzing at least six out of a set of twelve micropollutants, including those considered in this study. The treatments were conducted using three commercial RO membranes and one commercial NF membrane. Our findings indicate that membrane technology alone can remove over 80% of the micropollutants studied, except benzotriazole. An analysis of the separation mechanisms was carried out to understand the performance of each CEC in relation to each membrane type, taking into account pollutant physicochemical properties and observed removal efficiencies. Full article

The manufacturing of integrated circuits involves multiple steps of chemical mechanical planarization (CMP) involving different materials. Mitigating CMP-induced defects is a main requirement of all CMP schemes. In this context, controlling galvanic corrosion is a particularly challenging task for planarizing device structures involving contact regions of different metals with dissimilar levels of corrosivity. Since galvanic corrosion occurs in the reactive environment of CMP slurries, an essential aspect of slurry engineering for metal CMP is to control the surface chemistries responsible for these bimetallic effects. Using a CMP system based on copper and cobalt (used in interconnects for wiring and blocking copper diffusion, respectively), the present work explores certain theoretical and experimental aspects of evaluating and controlling galvanic corrosion in barrier CMP. The limitations of conventional electrochemical tests for studying CMP-related galvanic corrosion are examined, and a tribo-electrochemical method for investigating these systems is demonstrated. Alkaline CMP slurries based on sodium percarbonate are used to planarize both Co and Cu samples. Galvanic corrosion of Co is controlled by using the metal-selective complex forming functions of malonic acid at the Co and Cu sample surfaces. A commonly used corrosion inhibitor, benzotriazole, is employed to further reduce the galvanic effects. Full article

The reuse of reclaimed water is essential for sustainable water management in arid regions. However, despite advancements in Wastewater Treatment Plants (WWTPs), certain micropollutants may persist. To address these challenges, the recently enacted European Urban Wastewater Treatment Directive (UWWTD) has established strict standards focused on monitoring twelve specific indicator compounds. In line with this, the present study aims to evaluate the concentrations and potential risks of these twelve UWWTD-designated compounds across various water sources, including surface water, groundwater, and effluents from a WWTP in the southeast of Spain. Although none of the evaluated water sources are, as expected, intended for human consumption, risks were assessed based on worst-case scenarios that could amplify their impact. The study assessed potential risks to human health across different age groups and ecosystems, focusing on key organisms such as fish, daphnia, and algae, using empirical assessment approaches. The risk assessment identified a low risk for most compounds regarding human health, except for citalopram (HRQ = 19.116) and irbesartan (HRQ = 1.104), which showed high human risk quotients (HQR > 1) in babies, particularly in reclaimed water. In terms of ecotoxicological risk, irbesartan presented the highest ecological risk quotient (ERQ = 3.500) in fish, followed by clarithromycin, with algae (ERQ = 1.500) being the most vulnerable organism. Furthermore, compounds like citalopram, venlafaxine, and benzotriazole exhibited moderate ecological risks (ERQ between 0.1 and 1) in the reclaimed water, and their risk was reduced in surface water and groundwater. Finally, this study discussed the potential impacts of elevated concentrations of these emerging compounds, emphasizing the need for rigorous wastewater monitoring to protect human health and ecosystem integrity. It also revealed notable differences in risk assessment outcomes when comparing two distinct evaluation approaches, further highlighting the complexities of accurately assessing these risks. Full article

The corrosive nature of ionic liquids (ILs) limits their potential as high-performance conductive lubricants in practical engineering applications. This study systematically investigates the effects of benzotriazole (BTA) as a corrosion inhibitor on the lubricating performance of ILs at different concentrations and applied currents, along with the underlying mechanisms. In the 0.5–5 A current range, BTA effectively reduces friction, wear, and arc erosion damage to the friction surface. As the applied current increases, the BTA-Fe reaction film suppresses oxide formation, thereby reducing electrical contact resistance (ECR). Moreover, the effectiveness of BTA is concentration-dependent: at 0.5 A and a BTA concentration of 0.5 wt%, the coefficient of friction (COF) decreases by 16.5%, and wear volume is reduced by 53.4%. Friction testing and surface analysis show that the BTA-IL combination exhibits synergistic lubrication and anti-corrosion effects under current-carrying conditions, with varying wear and lubrication mechanisms depending on the applied current. Full article

Recently, researchers have been committed to boosting the environmental friendliness and functional performance of multifunctional additives. In this study, an eco-friendly methylbenzotriazole-amide derivative (MeBz-2-C18) was designed and synthesized, with ethylamine serving as the linkage between methylbenzotriazole and the oleoyl chain. The structure of MeBz-2-C18 was characterized by nuclear magnetic resonance (NMR), high-resolution mass spectrometry (HR-MS), Fourier-transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). Subsequently, the storage stability and tribological behavior of MeBz-2-C18 and the commercial benzotriazole oleamide salt (T406) were comparatively evaluated. The covalently-bonded MeBz-2-C18 exhibits superior thermal stability, along with boosted storage stability and tribological performance in the synthetic base oil. Specifically, 0.5 wt.% addition of MeBz-2-C18 and T406 can reduce the average wear scar diameter (ave. WSD) by 21.6% and 13.9%, respectively. To further explore the micro-mechanism, the electrostatic potential (ESP) and worn surfaces were analyzed with scanning electron microscope-energy dispersive spectrometer (SEM–EDS), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations. The results show that MeBz-2-C18 possesses stronger adsorption on the metal surface, and its amide bond preferentially breaks during friction. This reduces the interfacial shear force and promotes the film formation of iron oxides, thus resulting in superior tribological performance. Full article

In this study, the removal of benzotriazole (BTA), a pervasive aquatic contaminant widely used for its anti-corrosion, UV-stabilizing, and antioxidant properties, by nanomagnetite, biochar, and nanomagnetite–biochar composite is investigated. Nanomagnetite and nanomagnetite–biochar composite were synthesized under anoxic conditions and tested for BTA removal efficiency at neutral pH under both oxic and anoxic conditions at different time scales. Within the short time scale (up to 8 h), the removal of BTA by nanomagnetite–biochar composite was shown to be due to BTA deprotonation by the nanomagnetite surface. Through proton liberation, Fe²⁺ is released in accordance with the reaction Fe₃O₄ + 2H⁺ → Fe₂O₃ + Fe²⁺ + H₂O, which likely influences BTA complexation and its possible redox degradation. On the longer time scale, biochar achieved higher removal efficiency: 50% BTA removed within 48 h, due to formation of a ternary complex with surface Ca²⁺ ions, or 75% BTA removed after HCl biochar acid wash followed by Ca²⁺ surface saturation. As BTA presents significant environmental risks due to its extensive industrial applications, the present study offers critical insights into the mechanisms of BTA removal by nanomagnetite–biochar composite, and highlights the potential of such materials for water treatment applications. Full article

This research focuses on the removal of emerging contaminants (CEC) present in synthetic aqueous matrices. Azole compounds were selected as CEC of interest due to their persistence and toxicity, particularly the triazole and oxazole groups. These compounds are also trace contaminants listed in the proposed revision of Directive 91/271/EEC on urban wastewater treatment and the 3rd European Union Observation List (Implementing Decision EU 2020/116), highlighting their regulatory importance. The draft Directive includes the implementation of quaternary treatments to achieve the highest possible removal rates of micropollutants. Among the technologies used on a large scale are some advanced oxidation processes (AOP), often combined with adsorption on activated carbon (AC). Laboratory-scale pilot plants have been designed and operated in this research, including UV photolysis and oxidation with H₂O₂ and adsorption with GAC. The results demonstrate that UV photolysis is able to remove all the selected CECs except fluconazole, reaching eliminations higher than 86% at high doses of 31.000 J/m². Treatment by H₂O₂ achieved removals of 4 to 55%, proving to be ineffective in the degradation of persistent compounds when acting as a single technology. Adsorption by AC is improved with longer contact times, reaching removals above 80% for benzotriazole and methyl benzotriazole at short contact times, followed by sulfamethoxazole and tebuconazole. Fluconazole had a mean adsorption capacity at low contact times, while metconazole and penconazole showed low adsorption capacities. Full article

Bionic superhydrophobic coatings were prepared on Q235 steel substrates by combining hexamethylenetetramine (HMTA) and benzotriazole (BTA) with methyltrimethoxysilane (MTMS), nano-silica, zinc oxide, and polydimethylsiloxane (PDMS). Three-dimensional morphology analysis revealed micro- and nanostructures in the coating. The coating’s corrosion resistance was demonstrated through electrochemical impedance spectroscopy (EIS). X-ray photoelectron spectroscopy (XPS) analysis confirmed zinc oxide embedding within the micro- and nano-rough structures. The optimized bionic coating achieved a contact angle (CA) of 161.2° and a sliding angle (SA) of 2.0°. The bionic coatings demonstrated low adhesion, dynamic hydrophobicity, and self-cleaning properties when exposed to various liquids and contaminants. The corrosion inhibition mechanism of BTA and HMTA in superhydrophobic coatings involves a synergistic combination of chemisorption, complexation, and physical barrier effects. This MTMS-SiO₂-ZnO-PDMS-HMTA-BTA coating demonstrated the highest protection efficiency among the tested formulations. The optimized coating achieved a protection efficiency of 92.12%. Additionally, the bionic coating demonstrated effective UV resistance, maintaining a contact angle of 153.7° after 120 h of UV exposure. Full article