A novel cobalt-iron bimetallic hydrochar for the degradation of triclosan in the aqueous solution: performance, reusability, and synergistic degradation mechanism.

Low activation performance is a critical issue limiting the practical application of low-cost biochar in the advanced oxidation. Given the high potential of transition metals in the persulfate activation process and abundant oxygen-containing groups of hydrochar, hydrochar derived from cobalt (Co)-modified iron (Fe)-enriched sludge was synthesized and its performance and activation mechanism for the degradation of triclosan were investigated. Co modification significantly altered the morphology of hydrochar, and the increased Co-Fe mass ratios transformed hydrochar from granular to rose-shaped lamellar and then to helical sheet structures. Specific surface area, defect degree, and oxygen-containing groups of hydrochar increased with increasing cobalt-iron mass ratios. The highest removal of triclosan was up to 98% in the hydrochar/peroxymonosulfate (PMS) system under a wide range of pHs (3-10) and still remained higher than 90% after four cycles. Both Radical (mainly hydroxyl radical) and nonradical pathways (singlet oxygen and electron transfer) were evidenced to play roles in the triclosan removal. Fe3+ promoted the regeneration of Co2+ and realized the efficient circulation of Co3+/Co2+. A ternary system consisting of electron donor (triclosan)-electron mediator (hydrochar)-electron acceptor (PMS) provided channels for electron transfer. No measurable Co and Fe were released during the reaction, and the toxicity of degradation intermediates was lower than that of triclosan. Beside triclosan, rhodamine B, bisphenol A, sulfamethoxazole, and phenol were also almost degraded completely in this oxidation system. This study provides a promising way for the enhancement of catalytic activity of carbonaceous material.

Fluorine-functionalized covalent organic framework coated solid-phase microextraction probe coupled with electrospray ionization mass spectrometry for monitoring triclosan, triclocarban, and chlorophenols in mice.

Triclosan (TCS), triclocarban (TCC), and chlorophenols (CPs) are broad-spectrum antibacterials widely used in dermatological and oral hygiene products, which could induce severe liver and intestine injuries. Hence, it is essential to establish a rapid and sensitive method to monitor TCS, TCC, and CPs in various organisms. In this work, fluorine-functionalized covalent organic framework (COF-F) was prepared by using 4,4',4''-(1,3,5-triazine-2,4,6-triyl)tri-aniline and 2,3,5,6-tetrafluoroterephthalaldehyde as two building units and employed as a solid phase microextraction (SPME) probe for the extraction of TCS, TCC and CPs. The COF-F possessed excellent hydrophobicity, a large specific surface area (1354.3 m2 g-1) and high uniform porosity (3.2 nm), which facilitated high selectivity and adsorption properties towards TCS, TCC, and CPs. Therefore, the as-prepared COF-F-SPME in combination with electrospray ionization mass spectrometry has been developed to provide fast and ultrasensitive detection of TCS, TCC, and CPs in biological samples. The established method demonstrated satisfactory linear ranges (0.01-100.00 µg L-1) and low limits of detection (0.003-0.040 µg L-1) for TCS, TCC and CPs. The developed method could be successfully applied to detect TCS, TCC and CPs in the liver and kidney tissues of mice, demonstrating the potential for the detection of chlorinated aromatic pollutants in the biological samples.

Characterization and Performance of Peanut Shells in Caffeine and Triclosan Removal in Batch and Fixed-Bed Column Tests.

Peanut shells' adsorption performance in caffeine and triclosan removal was studied. Peanut shells were analyzed for their chemical composition, morphology, and surface functional groups. Batch adsorption and fixed-bed column experiments were carried out with solutions containing 30 mg/L of caffeine and triclosan. The parameters examined included peanut shell particle size (120-150, 300-600, and 800-2000 µm), adsorbent dose (0.02-60 g/L), contact time (up to 180 min), bed height (4-8 cm), and hydraulic loading rate (2.0 and 4.0 m3/m2-day). After determining the optimal adsorption conditions, kinetics, isotherm, and breakthrough curve models were applied to analyze the experimental data. Peanut shells showed an irregular surface and consisted mainly of polysaccharides (around 70% lignin, cellulose, and hemicellulose), with a specific surface area of 1.7 m2/g and a pore volume of 0.005 cm3/g. The highest removal efficiencies for caffeine (85.6 ± 1.4%) and triclosan (89.3 ± 1.5%) were achieved using the smallest particles and 10.0 and 0.1 g/L doses over 180 and 45 min, respectively. Triclosan showed easier removal compared to caffeine due to its higher lipophilic character. The pseudo-second-order kinetics model provided the best fit with the experimental data, suggesting a chemisorption process between caffeine/triclosan and the adsorbent. Equilibrium data were well-described by the Sips model, with maximum adsorption capacities of 3.3 mg/g and 289.3 mg/g for caffeine and triclosan, respectively. In fixed-bed column adsorption tests, particle size significantly influenced efficiency and hydraulic behavior, with 120-150 µm particles exhibiting the highest adsorption capacity for caffeine (0.72 mg/g) and triclosan (143.44 mg/g), albeit with clogging issues. The experimental data also showed good agreement with the Bohart-Adams, Thomas, and Yoon-Nelson models. Therefore, the findings of this study highlight not only the effective capability of peanut shells to remove caffeine and triclosan but also their versatility as a promising option for water treatment and sanitation applications in different contexts.

Tailoring CuOx loading on CoFe2O4 nanocubes photocatalyst for superior photocatalytic degradation of triclosan pollutants under VL irradiation and toxicological evaluation.

In this study, we report the development of a novel CuOx(3 wt%)/CoFe2O4 nanocubes (NCs) photocatalyst through simple co-precipitation and wet impregnation methods for the efficient photocatalytic degradation of triclosan (TCS) pollutants. Initially, rod-shaped bare CoFe2O4 was synthesized using a simple co-precipitation technique. Subsequently, CuOx was loaded in various percentages (1, 2, and 3 wt%) onto the surface of bare CoFe2O4 nanorods (NRs) via the wet impregnation method. The synthesized materials were systematically characterized to evaluate their composition, structural and electrical characteristics. The CuOx(3 wt%)/CoFe2O4 NCs photocatalyst exhibited superior photocatalytic degradation efficiency of TCS (89.9%) compared to bare CoFe2O4 NRs (62.1 %), CuOx(1 wt%)/CoFe2O4 (80.1 %), CuOx(2 wt%)/CoFe2O4 (87.0 %) under visible light (VL) irradiation (λ ≥ 420 nm), respectively. This enhanced performance was attributed to the improved separation effectiveness of photogenerated electron (e-) and hole (h+) in CuOx(3 wt%)/CoFe2O4 NCs. Furthermore, the optimized CuOx(3 wt%)/CoFe2O4 NCs exhibited strong stability and reusability in TCS degradation, as demonstrated by three successive cycles. Genetic screening on Caenorhabditis elegans showed that CuOx(3 wt%)/CoFe2O4 NCs reduced ROS-induced oxidative stress during TCS photocatalytic degradation. ROS levels decreased at 30, 60, and 120-min intervals during TCS degradation, accompanied by improved egg hatching rates. Additionally, expression levels of stress-responsible antioxidant proteins like SOD-3GFP and HSP-16.2GFP were significantly normalized. This study demonstrates the efficiency of CuOx(3 wt%)/CoFe2O4 NCs in degrading TCS pollutants, offers insights into toxicity dynamics, and recommends its use for future environmental remediation.

In vitro cytocompatibility of triclosan coated Polyglactin910 sutures.

Bioabsorbable sutures can improve the medical functions of existing non-absorbable sutures, and may produce new medical effects, and are expected to become a new generation of medical degradable materials. In this study, the cytocompatibility of triclosan coated polyglactin910 sutures (CTS-PLGA910) was analyzed and different concentrations of sutures were prepared. The effects of sutures on the cytotoxicity and cell proliferation of HUVEC were studied by CCK-8 assay. The hemolysis, total antioxidant capacity (T-AOC) activity and nitric oxide (NO) content were investigated to improve the blood compatibility of sutures. The results showed that the hemolysis rate of CTS-PLGA910 was less than 5%. After treatment on HUVEC cells for 48 and 72 h, there was no significant change in NO content in CTS-PLGA910 groups compared with the control group, while T-AOC activity and antioxidant capacity were significantly increased in medium and high dose groups. In summary, the blood compatibility and cell compatibility were significantly improved, which provided a basis for the clinical application of sutures in the future.

Cu-promoted synthesis of triclosan-Mannich and Glaser adducts: anti-mycobacterial evaluation with in silico validations.

Aim: The WHO, Global tuberculosis report 2022 estimated number of tuberculosis (TB) cases reached 10.6 million in 2021, reflecting a 4.5% increase compared with the 10.1 million reported in 2020. The incidence rate of TB showed 3.6% rise from 2020 to 2021. Results/methodology: This manuscript discloses Cu-promoted single pot A3-coupling between triclosan (TCS)-based alkyne, formaldehyde and secondary amines to yield TCS-based Mannich adducts. Additionally, the coupling of TCS-alkynes in the presence of Cu(OAc)2 afforded the corresponding homodimers. Among tested compounds, the most potent one in the series 11 exhibited fourfold higher potency than rifabutin against drug-resistant Mycobacterium abscessus. The selectivity index was also substantially improved, being 26 (day 1) and 15 (day 3), which is four-times better than TCS.

[Box: see text].

Optimized preparation of Ni-Febm bimetallic particles by ball milling NiSO4 and iron powder for efficient removal of triclosan.

The excessive usage and emissions of triclosan (TCS) pose a serious threat to aquatic environments. Iron-based bimetallic particles (Pd/Fe, Ni/Fe, and Cu/Fe, etc.) were widely used for the degradation of chlorophenol pollutants. This study proposed a novel synthesis method for the preparation of Ni/Fe bimetallic particles (Ni-Febm) by ball milling microscale zero valent iron ZVI (mZVI) and NiSO4. Ball-milling conditions such as ball-milling time, ball-milling speed and ball-to-powder ratio were optimized to prepare high activity Ni-Febm bimetallic particles. During the ball-milling process, Ni2+ was reduced to Ni0 and formed a coupled structure with ZVI. The amount of Ni0 on ZVI significantly affected the activity of Ni-Febm bimetallic particles. The highest activity Ni-Febm bimetallic particles with Ni/Fe ratio of 0.03 were synthesized under optimized conditions, which could remove 86.56% of TCS (10 µM) in aerobic aqueous solution within 60 min. In addition, higher particle dosage, lower pH condition and higher reaction temperature were more conducive for TCS degradation. The higher corrosion current and lower electron transfer impedance of Ni-Febm bimetallic particles were the main reasons for its high activity. The hydrogen atom (•H) on the surface of Ni-Febm bimetallic particles was mainly contributed to the removal of TCS, as reductive transformation products of TCS were detected by LC-TOF-MS. Notably, a small amount of oxidation products were discovered. The total dechlorination rate of TCS was calculated to be 39.67%. After eight reaction cycles, the residual Ni-Febm bimetallic particles could still degrade 28.34% of TCS within 6 h. Low Ni2+ leaching during reaction indicated that Ni-Febm bimetallic particles did not pose potential environmental risks. The prepared environmental-friendly Ni-Febm bimetallic particles with high activity have great potential in the degradation of other chlorinated organic compounds in wastewater.

Synthesis of recyclable and light-weight graphene oxide/chitosan/genipin sponges for the adsorption of diclofenac, triclosan, and microplastics.

Emerging micropollutants, such as pharmaceuticals and microplastics (MPs), have become a pressing water environmental concern. The aim of this study is to synthesize chitosan sponges using graphene oxide (GO) and genipin (GP) for the removal of pharmaceuticals (diclofenac (DCF) and triclosan (TCS)) and MPs, verify their adsorption mechanisms, evaluate the effects of temperature, pH, and salinity on their adsorption capacities, and determine their reusability. The GO5/CS/GP sponge exhibited a macroporous nature (porosity = 95%, density = 32.6 mg/cm3). GO and cross-linker GP enhanced the adsorption of DCF, TCS, and polystyrene (PS) MPs onto the CS sponges. The adsorption of DCF, TCS, and PS MPs involved multiple steps: surface diffusion and pore diffusion of the sponge. The adsorption isotherms demonstrated that Langmuir model was the most fitted well model to explain adsorption of TCS (qm = 7.08 mg/g) and PS MPs (qm = 7.42 mg/g) on GO5/CS/GP sponge, while Freundlich model suited for DCF adsorption (qm = 48.58 mg/g). DCF adsorption was thermodynamically spontaneous and endothermic; however, the adsorption of TCS and PS MPs was exothermic (283-313 K). The optimal pH was 5.5-7 due to the surface charge of the GO5/CS/GP sponge (pHzpc = 5.76) and ionization of DCF, TCS, and PS MPs. As the salinity increased, DCF removal efficiency drastically decreased due to the weakening of electrostatic interactions; however, TCS removal efficiency remained stable because TCS adsorption was mainly caused by hydrophobic and π-π interactions rather than electrostatic interaction. The removal of PS MPs was enhanced by the electrostatic screening effects of high Na+ ions. PS nanoplastics (average size = 26 nm) were removed by the GO5/CS/GP sponge at a rate of 73.0%, which was better than that of PS MPs (41.5%). In addition, the GO5/CS/GP sponge could be recycled over five adsorption-desorption cycles.

Light-degradable nanocomposite hydrogels for antibacterial wound dressing applications.

Skin injuries infected by bacteria can cause life-threatening human diseases if not treated properly. In this work, we developed a light-degradable nanocomposite hydrogel to achieve both controlled antibiotic delivery and hydrogel degradation using light as the sole stimulus. Specifically, we incorporated triclosan-loaded, poly(N-isopropylacrylamide)-based nanogels (TCS-NGs) that exhibited potent antibacterial efficacy, into a light-degradable poly (ethylene glycol) (PEG)-based hydrogel matrix via simple physical entrapment method. Upon exposure to 365 nm light, the hydrogel matrix could rapidly degrade, which subsequently released the entrapped TCS-NGs into the surrounding environment. Our results demonstrated that TCS-NGs released from light-degradable nanocomposite hydrogels still possessed remarkable antibacterial efficacy by inhibiting the growth of Staphylococcus aureus both in solution (a fivefold reduction in optical density compared to the blank control) and on bacteria-infected porcine skins (a fivefold reduction in colony-forming units compared to the blank control). Finally, using an alamarBlue assay on human dermal fibroblasts, we determined that each component of the nanocomposite hydrogel exhibited excellent biocompatibility (>90% cell viability) and would not cause significant cytotoxicity. Overall, the fabricated light-degradable nanocomposite hydrogels could serve as novel material for antibacterial wound dressing applications.

Human intake assessment of triclosan associated with the daily use of polypropylene-made antimicrobial food packaging.

In this work, we aimed to evaluate human intake of triclosan (TCS) associated with real-life use of different brands of Microban™ microwave-safe food packaging. Calculations were based on: TCS migration data (under the worst-case foreseeable conditions), MPs abundance and TCS bioaccessibility from microplastics (MPs), leached from containers under microwave heating. Bioaccessibility studies were performed with in vitro digestion of MPs, followed by liquid-liquid extraction of TCS from digestive fluids and LC-QqQ-MS analysis yielding values of 46 ± 9%. The estimated weekly intake (EWI) of TCS ranged between 11 and 42 µg/kg body weight/week, with migration being the largest contribution (0.6-2.3 mg/week), compared to leaching of MPs (75-300 µg/week). These values represent a significant source of human exposure to TCS, emphasizing the need to harmonize the ban of TCS in food contact materials worldwide and improve compliance testing of food contact articles, particularly those marketed through online sales platforms.

Enhanced dewaterability and triclosan removal of waste activated sludge with iron-rich mineral-activated peroxymonosulfate.

High water and pharmaceutical and care products (PPCPs) bounded in sludge flocs limit its utilization and disposal. The advanced oxidation process of perxymonosulfate (PMS) catalyzed by iron salts has been widely used in sludge conditioning. In this study, two iron-rich minerals pyrite and siderite were proposed to enhance sludge dewatering performance and remove the target contaminant of triclosan (TCS). The permanent release of Fe2+ in the activation of PMS made siderite more effective in enhancing sludge dewater with capillary suction time (CST) diminishing by 60.5 %, specific resistance to filtration (SRF) decreasing by 79.2 %, and bound water content (BWC) dropping from 37.1 % to 2.6 % at siderite/PMS dosages of 0.36/0.20 mmol/g-TSS after 20 min of pretreatment. Pyrite/PMS performed slightly inferior under the same conditions and the corresponding CST and SRF decreased by 51.5 % and 71.8 % while the BWC only declined to 17.8 %. Rheological characterization was employed to elucidate the changes in sludge dewatering performance, with siderite/PMS treated sludge showing a 48.3 % reduction in thixotropy, higher than 28.4 % of pyrite/PMS. Oscillation and creep tests further demonstrated the significantly weakened viscoelastic behavior of the sludge by siderite/PMS pretreatment. For TCS mineralization removal, siderite/PMS achieved a high removal efficiency of 43.9 %, in comparison with 39.9 % for pyrite/PMS. The reduction in the sludge solids phase contributed the most to the TCS removal. Free radical quenching assays and EPR spectroscopy showed that both siderite/PMS and pyrite/PMS produced SO4-·  and ·OH, with the latter acting as the major radicals. Besides, the dosage of free radicals generated from siderite/PMS exhibited a lower time-dependence, which also allowed it to outperform in destroying EPS matrix, neutralizing the negative Zeta potential of sludge flocs, and mineralizing macromolecular organic matter.

Efficient removal of triclosan from water through activated carbon adsorption and photodegradation processes.

This study investigated the application of adsorption with activated carbons (ACs) and photodegradation to reduce the concentration of triclosan (TCS) in aqueous solutions. Concerning adsorption, ACs (Darco, Norit, and F400) were characterised and batch experiments were performed to elucidate the effect of pH on equilibrium. The results showed that at pH = 7, the maximum adsorption capacity of TCS onto the ACs was 18.5 mg g-1 for Darco, 16.0 mg g-1 for Norit, and 15.5 mg g-1 for F400. The diffusional kinetic model allowed an adequate interpretation of the experimental data. The effective diffusivity varied and increased with the amount of TCS adsorbed, from 1.06 to 1.68 × 10-8 cm2 s-1. In the case of photodegradation, it was possible to ensure that the triclosan molecule was sensitive to UV light of 254 nm because the removal was over 80 % using UV light. The removal of TCS increased in the presence of sulfate radicals. It was possible to identify 2,4-dichlorophenol as one of the photolytic degradation products of triclosan, which does not represent an environmental hazard at low concentrations of triclosan in water. These results confirm that the use of AC Darco, Norit, and F400 and that photodegradation processes with UV light and persulfate radicals are effective in removing TCS from water, reaching concentration levels that do not constitute a risk to human health or environmental hazard. Both methods effectively eliminate pollutants with relatively easy techniques to implement.

Polyzwitterionic micelles with antimicrobial-conjugation for eradication of drug-resistant bacterial biofilms.

The presence of bacterial biofilms has presented a significant challenge to human health. This study presents the development of biofilm microenvironment-responsive polymeric micelles as a novel approach to address the challenges posed by bacterial biofilms. These micelles are composed of two key components: a zwitterionic component, inspired by protein isoelectric points, containing balanced quantities of primary amines and carboxylic groups that undergo a positive charge transformation in acidic microenvironments, and a hydrophobic triclosan conjugate capable of releasing triclosan in the presence of bacterial lipases. Through the synergistic combination of pH-responsiveness and lipase-responsiveness, we have significantly improved drug penetration into biofilms and enhanced its efficacy in killing bacteria. With their remarkable drug-loading capacity and the ability to specifically target and eliminate bacteria within biofilms, these zwitterionic polymeric micelles hold great promise as an effective alternative for treating biofilm-associated infections. Their unique properties enable efficient drug delivery and heightened effectiveness against biofilm-related infections.

π-π stack driven competitive /complementary adsorption of aromatic compounds on MIL-53(Al).

In this study, the selective adsorption of aromatic compounds on mesoporous MIL-53(Al) was investigated, and followed the order: Biphenyl (Biph) > Triclosan (TCS) > Bisphenol A (BPA) > Pyrogallol (Pyro) > Catechol (Cate) > Phenol (Phen), and exhibited high selectivity toward TCS in binary compounds. In addition to hydrophobicity and hydrogen bonding, π-π interaction/stacking predominated, and more evidently with double benzene rings. TCS-containing halogens could increase π interaction on the benzene rings via forming Cl-π stacking with MIL-53(Al). Moreover, site energy distribution confirmed that complementary adsorption mainly occurred in the Phen/TCS system, as evidenced by ΔQpri (the decreased solid-phase TCS concentration of the primary adsorbate) < Qsec (the solid-phase concentrations of the competitor (Phen)). In contrast, competitive sorption occurred in the BPA/TCS and Biph/TCS systems within 30 min due to ΔQpri = Qsec, followed by substitution adsorption in the BPA/TCS system, but not for the Biph/TCS system, likely attributed to the magnitude of energy gaps (Eg) and bond energy of TCS (1.80 eV, 362 kJ/mol) fallen between BPA (1.74 eV, 332 kJ/mol) and Biph (1.99 eV, 518 kJ/mol) according to the density-functional theory of Gaussian models. Biph with a more stable electronic homeostasis than TCS lead to the occurrence of substitution adsorption in the TCS/BPA system, but not in the TCS/Biph system. This study provides insight into the mechanisms of different aromatic compounds on MIL-53(Al).

Structure-Based Design and Pharmacophore-Based Virtual Screening of Combinatorial Library of Triclosan Analogues Active against Enoyl-Acyl Carrier Protein Reductase of Plasmodium falciparum with Favourable ADME Profiles.

Cost-effective therapy of neglected and tropical diseases such as malaria requires everlasting drug discovery efforts due to the rapidly emerging drug resistance of the plasmodium parasite. We have carried out computational design of new inhibitors of the enoyl-acyl carrier protein reductase (ENR) of Plasmodium falciparum (PfENR) using computer-aided combinatorial and pharmacophore-based molecular design. The Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA) complexation QSAR model was developed for triclosan-based inhibitors (TCL) and a significant correlation was established between the calculated relative Gibbs free energies of complex formation (∆∆Gcom) between PfENR and TCL and the observed inhibitory potencies of the enzyme (IC50exp) for a training set of 20 known TCL analogues. Validation of the predictive power of the MM-PBSA QSAR model was carried out with the generation of 3D QSAR pharmacophore (PH4). We obtained a reasonable correlation between the relative Gibbs free energy of complex formation ∆∆Gcom and IC50exp values, which explained approximately 95% of the PfENR inhibition data: pIC50exp=-0.0544×∆∆Gcom+6.9336,R2=0.95. A similar agreement was established for the PH4 pharmacophore model of the PfENR inhibition (pIC50exp=0.9754×pIC50pre+0.1596, R2=0.98). Analysis of enzyme-inhibitor binding site interactions suggested suitable building blocks to be used in a virtual combinatorial library of 33,480 TCL analogues. Structural information derived from the complexation model and the PH4 pharmacophore guided us through in silico screening of the virtual combinatorial library of TCL analogues to finally identify potential new TCL inhibitors effective at low nanomolar concentrations. Virtual screening of the library by PfENR-PH4 led to a predicted IC50pre value for the best inhibitor candidate as low as 1.9 nM. Finally, the stability of PfENR-TCLx complexes and the flexibility of the active conformation of the inhibitor for selected top-ranking TCL analogues were checked with the help of molecular dynamics. This computational study resulted in a set of proposed new potent inhibitors with predicted antimalarial effects and favourable pharmacokinetic profiles that act on a novel pharmacological target, PfENR.

Adsorption behavior of triclosan on microplastics and their combined acute toxicity to D. magna.

Microplastics (MP) have been recently identified as emerging water contaminants in worldwide. Owing to its physicochemical properties, MP have been considered as a vector of other micropollutants and may affect their fate and ecological toxicity in the water environment. In this study, triclosan (TCS), which is a widely-used bactericide, and three frequently found types of MP (PS-MP, PE-MP, and PP-MP) were investigated. The adsorption behavior of TCS on MP was investigated by the effect of reaction time, initial concentration of TCS, and other water chemistry factors. Elovich model and Temkin model are the most fitted well with kinetics and adsorption isotherms, respectively. The maximum TCS adsorption capacities were calculated for PS-MP (9.36 mg/g), PP-MP (8.23 mg/g), and PE-MP (6.47 mg/g). PS-MP had higher affinity to TCS owing to hydrophobic and π-π interaction. The TCS adsorption on PS-MP was inhibited by decreasing concentrations of cations, and increasing concentration of anion, pH, and NOM concentration. At pH 10, only 0.22 mg/g of adsorption capacity was obtained because of the isoelectric point (3.75) of PS-MP and pKa (7.9) of TCS. And almost no TCS adsorption occurred at NOM concentration of 11.8 mg/L. Only PS-MP had no acute toxic effect on D. magna, whereas TCS showed acute toxicity (EC50,24h of TCS = 0.36 ± 0.4 mg/L). Although survival rate increased when TCS with PS-MP due to lower the TCS concentration in solution via adsorption, PS-MP was observed in intestine and body surface of D. magna. Our findings can contribute to understanding the combined potential effects of MP fragment and TCS to aquatic biota.

Microplastics and organics - A comparative study of sorption of triclosan and malachite green onto polyethylene.

This study aims to elucidate interaction of organics with microplastics in a comparative manner via the use of two model compounds (i.e., triclosan (TCS) and malachite green (MG)) having different physicochemical properties, onto polyethylene (PE). TCS, is hydrophobic with low solubility, while MG is hydrophilic with high aqueous solubility. Kinetic studies indicate faster sorption (teq = 24 h) and equilibrium studies show much higher capacity (qe = 6,921 µg/g) for TCS, when compared to those of MG (teq = 5 d, qe = 221 µg/g). While pseudo-kinetic model fits sorption of both organics to PE, equilibrium isotherms as well as the results on effect of particle size and pH indicate dissimilar sorption mechanisms. Considering pHPZC = 2, observation of favourable sorption of TCS in acidic regions and sorption being unaffected by particle size was explained by TCS sorption to be dominated by hydrophobic interactions in amorph regions of PE. Higher removal of MG was observed at lower surface charge of PE, and a clear favourable impact of surface area on MG sorptive capacity pointed to the presence of non-specific van der Waals type interactions on the surface of PE. Mechanistic evaluations presented here contribute to our understanding of interaction of MPs with organics in aquatic ecosystems.

Triclosan and triclocarban weaken the olfactory capacity of goldfish by constraining odorant recognition, disrupting olfactory signal transduction, and disturbing olfactory information processing.

Recently, increased production and consumption of disinfectants such as triclosan (TCS) and triclocarban (TCC) have led to massive pollution of the environment, which draws global concern over the potential risk to aquatic organisms. However, the olfactory toxicity of disinfectants in fish remains elusive to date. In the present study, the impact of TCS and TCC on the olfactory capacity of goldfish was assessed by neurophysiological and behavioral approaches. As shown by the reduced distribution shifts toward amino acid stimuli and hampered electro-olfactogram responses, our results demonstrated that TCS/TCC treatment would cause deterioration of the olfactory ability of goldfish. Our further analysis found that TCS/TCC exposure suppressed the expression of olfactory G protein-coupled receptors in the olfactory epithelium, restricted the transformation of odorant stimulation into electrical responses by disturbing the cAMP signaling pathway and ion transportation, and induced apoptosis and inflammation in the olfactory bulb. In conclusion, our results demonstrated that an environmentally realistic level of TCS/TCC would weaken the olfactory capacity of goldfish by constraining odorant recognition efficiency, disrupting olfactory signal generation and transduction, and disturbing olfactory information processing.

Biotreatment efficiency, degradation mechanism and bacterial community structure in an immobilized cell bioreactor treating triclosan-rich wastewater.

Biotreatment of triclosan is mainly performed in conventional activated sludge systems, which, however, are not capable of completely removing this antibacterial agent. As a consequence, triclosan ends up in surface and groundwater, constituting an environmental threat, due to its toxicity to aquatic life. However, little is known regarding the diversity and mechanism of action of microbiota capable of degrading triclosan. In this work, an immobilized cell bioreactor was setup to treat triclosan-rich wastewater. Bioreactor operation resulted in high triclosan removal efficiency, even greater than 99.5%. Nitrogen assimilation was mainly occurred in immobilized biomass, although nitrification was inhibited. Based on Illumina sequencing, Bradyrhizobiaceae, followed by Ferruginibacter, Thermomonas, Lysobacter and Gordonia, were the dominant genera in the bioreactor, representing 38.40 ± 0.62% of the total reads. However, a broad number of taxa (15 genera), mainly members of Xanthomonadaceae, Bradyrhizobiaceae and Chitinophagaceae, showed relative abundances between 1% and 3%. Liquid Chromatography coupled to Quadrupole Time-Of-Flight Mass Spectrometry (LC-QTOF-MS) resulted in the identification of catabolic routes of triclosan in the immobilized cell bioreactor. Seven intermediates of triclosan were detected, with 2,4-dichlorophenol, 4-chlorocatechol and 2-chlorohydroquinone being the key breakdown products of triclosan. Thus, the immobilized cell bioreactor accommodated a diverse bacterial community capable of degrading triclosan.

Efficient and selective use of functionalized material in the decontamination of water: removal of emerging micro-pollutants from aqueous wastes.

The contamination of the aquatic environment with emerging micro-pollutants is a serious global concern. The aim of this investigation was to synthesize novel functionalized material (BNAPTES) precursor to natural bentonite in a single pot facile synthetic route. The material was utilized for efficient and selective removal of tetracycline (TC) and triclosan (TCS) in aqueous wastes. The grafting of silane was confirmed with the FT-IR (Fourier Transform Infra-Red) analysis and the EDX (Energy Dispersive X-ray) analysis showed the incorporation of amino group with the bentonite. The structural changes of clay due to silane grafting were studied with the help of XRD (X-ray Diffraction) and BET (Brunner-Emmett-Teller) surface area analyses. Batch adsorption studies showed that functionalized clay significantly increased the selectivity and adsorption capacity of bentonite for TC and TCS. The Langmuir monolayer adsorption capacity was found to be 15.36 and 17.15 mg/g for TC and TCS, respectively. The rapid uptake of TC and TCS by functionalized material followed pseudo-second-rate kinetics. Further, a total of 78% of TC and 73% of TCS were removed within 5 min of contact and the adsorption equilibrium was achieved within 120  min. The influence of background electrolytes and co-existing ions indicated that TC and TCS were selective towards BNAPTES. The loading capacities of the column packed with BNAPTES were found to be 56.00 and 44.42 mg/g for TC and TCS, respectively. Further, BNAPTES was found efficient even in real water treatment since the attenuation of TC and TCS was not affected significantly in the real water matrix.