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Since ancient times, honey has been used for medical purposes and the treatment of various disorders. As a high-quality food product, the honey industry is prone to fraud and adulteration. Moreover, limited experimental studies have investigated the impact of adulterated honey consumption using zebrafish as the animal model. The aims of this study were: (1) to calculate the lethal concentration (LC 50) of acid-adulterated Apis mellifera honey on embryos, (2) to investigate the effect of pure and acid-adulterated A. mellifera honey on hatching rate (%) and heart rate of zebrafish (embryos and larvae), (3) to elucidate toxicology of selected adulterated honey based on lethal dose (LD 50) using adult zebrafish and (4) to screen the metabolites profile of adulterated honey from blood serum of adult zebrafish. The result indicated the LC 50 of 31.10 ± 1.63 (mg/ml) for pure A. mellifera honey, while acetic acid demonstrates the lowest LC 50 (4.98 ± 0.06 mg/ml) among acid adulterants with the highest mortality rate at 96 hpf. The treatment of zebrafish embryos with adulterated A. mellifera honey significantly (p ≤ 0.05) increased the hatching rate (%) and decreased the heartbeat rate. Acute, prolong-acute, and sub-acute toxicology tests on adult zebrafish were conducted at a concentration of 7% w/w of acid adulterants. Furthermore, the blood serum metabolite profile of adulterated-honey-treated zebrafish was screened by LC-MS/MS analysis and three endogenous metabolites have been revealed: (1) Xanthotoxol or 8-Hydroxypsoralen, (2) 16-Oxoandrostenediol, and (3) 3,5-Dicaffeoyl-4-succinoylquinic acid. These results prove that employed honey adulterants cause mortality that contributes to higher toxicity. Moreover, this study introduces the zebrafish toxicity test as a new promising standard technique for the potential toxicity assessment of acid-adulterated honey in this study and hazardous food adulterants for future studies. [Display omitted] • Embryotoxicity of pure and acid-adulterated Apis mellifera honey. • Lethal concentration and dose, hatching and heartbeat rate of pure and acid-adulterated Apis mellifera honey was evaluated. • Toxic endogenous metabolites were identified using LCMS/MS analysis. [ABSTRACT FROM AUTHOR]

Evaluating the toxicity of micropollutants forms the basis for understanding their potential risks to the ecosystem and/or human health. To accurately evaluate the toxicity of micropollutants in toxicity tests, many factors have been carefully considered, while the impact of the number of test organisms on toxicity results has rarely been taken into account. In this study, the role of the organism number on the developmental toxicity of five micropollutants was investigated using embryos of the marine polychaete Platynereis dumerilii. The toxicity of hydrophobic micropollutants was found to decrease significantly with increasing the number of embryos used in the test. A quantitative model was developed to better describe how the number of embryos affected developmental toxicity. The model showed a satisfactory fit to the raw data in all scenarios tested. The intrinsic half-maximal effective concentration EC 50,int was then determined using the model. For a given compound, the EC 50,int was a stable parameter that did not depend on the number of test embryos and thus provided an indication of the intrinsic toxicity of the compounds tested. Compared with the EC 50 values determined with the commonly used embryo number (around 120), the EC 50,int values of all tested hydrophobic micropollutants were lower. The more hydrophobic the compounds tested, the more pronounced the reduction in toxicity. This suggested that hydrophobic micropollutants could be more toxic than reported in the literature. Some suggestions were also made to eliminate the effect of the number of organisms used in the toxicity evaluation. [Display omitted] • The role of organism biomass on the toxicity assessment was studied for the first time. • The toxicity of hydrophobic micropollutants was largely restrained using high organism biomass. • A quantitative model was developed to describe the role of the tested embryo number. • Hydrophobic compounds might be more toxic than reported in the literature. • Some suggestions to obtain more accurate toxicity evaluation were provided. [ABSTRACT FROM AUTHOR]

Effluent organic matter (EfOM), which is composed of background natural organic matter (NOM), soluble microbial degradation products, and trace amounts of organic pollutants, can play an important role in the photodegradation of emerging pollutants in the effluent. In this study, the impact of organic pollutants, using fenofibrate acid (FNFA) as a representative, on the photodegradation of emerging contaminants, using bezafibrate (BZF) as a representative, in effluents was investigated. It is found that BZF undergo fast degradation in the presence of FNFA although BZF is recalcitrant to degradation under simulated sunlight irradiation. The promotional effect of FNFA is due to the generation of singlet oxygen (1O 2) and hydrated electrons (e- aq). Based on the structures of the identified intermediates, 1O 2 initiated oxidation and e- aq initiated reduction reactions were the main photodegradation pathways of BZF in the effluents. The toxicity of the main photodegradation intermediates for BZF and FNFA was higher than that of the parent compounds, and the acute toxicity increased during simulated sunlight irradiation. The results demonstrated that trace amounts of organic compounds in EfOM can play an important role in sensitizing the photodegradation of some emerging pollutants in the effluent. Image 1 • Trace amounts of organic pollutants sensitized photodegradation was investigated. • BZF undergoes efficient photodegradation in the presence of FNFA in effluents. • Hydrated electron was proved to involve in the photodegradation of organic pollutants. • Increased toxicity was observed and more toxic intermediates were generated from BZF. [ABSTRACT FROM AUTHOR]

Halogenated aromatic disinfection by-products (DBPs) are a new type of DBPs that have been detected in various water bodies. Previous studies have shown that most of them can induce in vivo toxicity in aquatic organisms. In this study, in order to further investigate the toxic effects and mechanisms of aromatic DBPs, the toxicity and ecological risks of 10 halogenated aromatic DBPs were assessed using the model organism zebrafish. It was found that the toxicity of DBPs was related to the number, type, and position of halogen and the type of substituent, and the 24 h-toxicity value of DBPs in this experiment could replace their 96 h-toxicity value to reduce the test time and save the test cost. Halogenated phenol and halogenated nitrophenol were more toxic, but the current ecological risks of DBPs were relatively low. In addition, the toxicity mechanism of DBPs was analyzed based on molecular docking and quantitative structure-activity relationship (QSAR) models. The molecular docking results showed that all 10 DBPs could bind to zebrafish's catalase (CAT), cytochrome P450 (CYP450), p53, and acetylcholinesterase (AChE), thereby affecting their normal life activities. QSAR models indicated that the toxicity of halogenated aromatic DBPs to zebrafish mainly depended on their hydrophobicity (log D), the interaction with CAT (E CAT), and hydrogen bonding acidity (A). [Display omitted] • Halogenated phenol and halogenated nitrophenol had higher toxicity to zebrafish. • The current ecological risks of halogenated aromatic DBPs were relatively low. • DBPs could affect zebrafish's CAT, CYP450, p53 and AchE based on molecular docking. • Log D, E CAT and A were the main factors affecting the toxicity mechanism of DBPs. [ABSTRACT FROM AUTHOR]

Abstract This study investigated the degradation of benzophenone-4 (BP-4) in a UV/chlorine disinfection process, with chlorination and UV disinfection as comparisons. With a degradation efficiency of 80% after 10 s, the UV/chlorine process significantly enhanced the degradation of BP-4. However, a rebound of 36% of the initial concentration was observed in the UV/chlorine process ([free active chlorine (FAC)] 0 :[BP-4] 0 = 1:1, pH = 7). The same tendency appeared under the addition of alkalinity, Cl−, and humic acid (HA). This work interpreted this interesting kinetic tendency from the perspective of mechanism. In fact, the transformation between the chlorinated product P1 and BP-4 was reversible under certain conditions. The inhomogeneous charge distribution of the C Cl bond in P1 led to the photolytic dechlorination of P1. This transformation caused an increase in BP-4 concentration. In addition, the increase in the UV light power promoted the photodecomposition of P1 under the experimental condition. In addition, this study evaluated the change in absorbable organic halogens (AOX) and three kinds of toxicity changes in the BP-4 solution after chlorination and the UV/chlorine process, including the acute toxicity of luminescent bacteria, endocrine disrupting effect and cytotoxicity. The UV/chlorine process exhibited lower ecotoxicity than chlorination in water treatment. Graphical abstract Image 1 Highlights • The UV/chlorine process significantly facilitated the degradation of BP-4. • Mutual transformation between the chlorinated product P1 and BP-4 was observed. • The inhomogeneous charge distribution of C Cl bond led to dechlorination of P1. • A more complete toxicity evaluation system was established. • UV/chlorination showed lower ecotoxicity than chlorination in water treatment. [ABSTRACT FROM AUTHOR]

Abstract Disinfection byproducts (DBPs) are produced during the disinfection of drinking water and pose a hazard to human health. As a typical type of DBPs, iodoacetic acid (IAA) exhibits prominent cytotoxicity in mammalian cell systems which links with oxidative stress. However, little is known about the relationship of catalase (CAT) with the cytotoxicity of IAA and the adverse effects of IAA to CAT. This study investigated the effects of IAA on the cell viability and CAT activity in the mouse primary hepatocytes. It was shown that IAA exposure induced the loss of cell viability and the increase of intracellular CAT activity. Intracellular CAT activity significantly increased due to the stimulation of CAT production under IAA exposure. The molecular CAT activity was inhibited due to the direct interaction of IAA with HIS 74 and TYR 357 around the active sites of CAT. IAA binds to CAT with (4.05 ± 1.98) sites via van der Waals and hydrogen bonding interactions, resulting in the loosening of protein skeletons and the change of protein size. Highlights • The work offers a combined cellular and molecular toxicity evaluation method. • CAT activity increased due to the stimulation of CAT production in the hepatocytes. • IAA triggered conformational changes in CAT and inhibit CAT activity. • IAA binds to CAT with (4.05 ± 1.98) sites mainly via van der Waals and hydrogen bonds. • IAA preferentially binds to the interface of CAT rather than its active site. [ABSTRACT FROM AUTHOR]

A photochemical system combining iron (hydr)oxides and oxalate (Ox) shows application prospects in wastewater treatment due to the abundance of reactive oxygen species (ROS) generation. Nevertheless, it is a challenge to the investigate photochemical activity of iron (hydr)oxides/Ox systems with varying structural properties. Herein, the photochemical behaviors of Ox on goethite (Gt) surface from the view of structural dependent activity, containment degradation, and ROS generation were explored in detail. Results confirmed that bidentate mononuclear was formed on Gt surface after complexing Ox. Combined with density functional theory calculation and pH time evolution during aniline degradation, the photochemical activity of the Gt/Ox system fell in between that of ferrihydrite/Ox and hematite/Ox systems. After irradiating 120 min visible light, 96.5% aniline was degraded by 1.0 mM Ox and 0.2 g/L Gt. The amount of •OH in vis/Gt/Ox system could be up to 309.3 μM and its generation was closely associated with Fe(II) while slightly affected by the generated H 2 O 2. Moreover, as revealed by high-performance liquid chromatography with mass spectrometric and Ecological Structure Activity Relationships software, the toxicity of the intermediates of aniline degradation in the vis/Gt/Ox system towards fish and green algae increased first but then declined accompanied by the generation of non-toxic ring-opening products at the end of reaction. According to the findings in the presented study, it could be concluded that vis/Gt/Ox is a promising approach to wiping out aniline wastewater. [Display omitted] • The structural dependent activity of Ox on Gt surface is studied. • Ox adsorption and detachment on Gt surface are investigated by in-situ ATR-FITR. • The dissolved O 2 is activated by CO 2 •− radicals and Fe(II) to generate ROS. • •OH generation is closely associated with Fe(II) rather than the intermediate H 2 O 2. • The toxicity of aniline degradation intermediates is firstly evaluated by ECOSAR. [ABSTRACT FROM AUTHOR]

Quantitative Structure-toxicity Relationship (QSTR) models were built to evaluate the toxicity of lignocellulose-derived phenolic inhibitors on the growth of Saccharomyces cerevisiae in a bioethanol production process. The established models were proved to be reliable after rigorous validation and showed values of R 2  > 0.6 and Q 2 LOO  > 0.5. They could provide accurate guidance for alleviating the most toxic inhibitors in pretreated lignocellulosic hydrolysates, thus facilitating bioethanol production. The results showed that the inhibitors that possessed unsaturated bonds, formyl groups and carbonyl group substituents showed obvious toxicity effects. The toxicity of the inhibitors with ortho-electron-withdrawing substituents was stronger than that of metra- or para-electron-donating substituents. Ferulic acid was chosen to analyze its toxicity in practical alkali-pretreated rice straw hydrolysates because of its strong toxicity and high concentration. The results showed that its toxicity was up to 82%, which was suggested to be dominantly detoxified in the bioethanol production process. [ABSTRACT FROM AUTHOR]

To examine the biodegradation of hydroxylated polychlorobiphenyls (OH-PCBs), we isolated Sphingomonas sp. strain N-9 from forest soil using mineral salt medium containing 4-hydroxy-3-chlorobiphenyl (4OH-3CB) at the concentration of 10 mg/L. Following incubation with strain N-9, the concentration of 4OH-3CB decreased in inverse proportion to strain N-9 proliferation, and it was converted to 3-chloro-4-hydroxybenzoic acid (4OH-3CBA) after 1 day. We observed that strain N-9 efficiently degraded lowly chlorinated OH-PCBs (1–4 Cl), while highly chlorinated OH-PCBs (5–6 Cl) were less efficiently transformed. Additionally, strain N-9 degraded PCBs and OH-PCBs with similar efficiencies, and the efficiency of OH-PCB degradation was dependent upon the positional relationships between OH-PCB hydroxyl groups and chlorinated rings. OH-PCB biodegradation may result in highly toxic products, therefore, we evaluated the cytotoxicity of two OH-PCBs [4OH-3CB and 4-hydroxy-3,5-dichlorobiphenyl (4OH-3,5CB)] and their metabolites [4OH-3CBA and 3,5-chloro-4-hydroxybenzoic acid (4OH-3,5CBA)] using PC12 rat pheochromocytoma cells. Our results revealed that both OH-PCBs induced cell membrane damage and caused neuron-like elongations in a dose-dependent manner, while similar results were not observed for their metabolites. These results indicated that strain N-9 can convert OH-PCBs into chloro-hydroxybenzoic acids having lower toxicity. [ABSTRACT FROM AUTHOR]

The pseudo-persistence of pharmaceutical and personal care products (PPCPs)in the aqueous environment may pose potential risks to human health and ecosystems. The UV disinfection in wastewater treatment plants is one of the essential processes before PPCPs enter the water environment, so it is crucial to elucidate the photolytic behavior and mechanism of PPCPs under UV radiation. In this work, carbamazepine (CBZ) and caffeine (CAF) were selected as typical pollutants to investigate the effect of water matrixes, humic acid, inorganic ions, and pH on the UV radiation performance. Hydroxyl radical (•OH) and singlet oxygen (1O 2) were identified by quenching experiments and electron paramagnetic resonance (EPR) spectra as playing a dominant role in the degradation process. UPLC-TOF/MS was conducted to identify 13 and 14 possible intermediates of CBZ and CAF, respectively. Moreover, combining density functional theory (DFT) calculations (Frontier Molecular Orbital and Fukui index), hydroxylation, oxidation, and ring cleavage were proposed as the main degradation pathways of the contaminants, which occurred first at the C(7C), N(17 N) and O(18O) sites of CBZ and at the C(9C) site of CAF. The bio-acute toxicity experiment and the Ecological Structure-Activity Relationships (ECOSAR) program were performed to analyze and predict the toxicity of the intermediates of CBZ and CAF under UV radiation, respectively. The results showed that the acute toxicity of both solutions increased after UV radiation and followed with the combined toxicity. This work has great scientific value and practical environmental significance for evaluating the UV disinfection process and managing PPCPs in the aqueous environment. [Display omitted] • The main active species were determined to be ·OH and 1O 2. • The reaction sites of CBZ and CAF were predicted by DFT. • Degradation pathways include hydroxylation, oxidation, and ring cleavage. • The compound toxicity of intermediates is higher than that of CBZ and CAF. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) are often claimed to be “environmentally friendly” compounds however, the knowledge of their potential toxicity towards different organisms and trophic levels is still limited, in particular when protic ionic liquids (PILs) are addressed. This study aims to evaluate the toxicity against various microorganisms and the biodegradability of four PILs namely, N-methyl-2-hydroxyethylammonium acetate, m-2-HEAA; N-methyl-2-hydroxyethylammonium propionate, m-2-HEAPr; N-methyl-2-hydroxyethylammonium butyrate, m-2-HEAB; and N-methyl-2-hydroxyethylammonium pentanoate, m-2-HEAP. The antimicrobial activity was determined against the two bacteria, Sthaplylococcus aureus ATCC-6533 and Escherichia coli CCT-0355; the yeast Candida albicans ATCC-76645; and the fungi Fusarium sp. LM03. The toxicity of all PILs was tested against the aquatic luminescent marine bacterium Vibrio fischeri using the Microtox ® test. The impact of the PILs was also studied regarding their effect on lettuce seeds ( Lactuta sativa ). The biodegradability of these PILs was evaluated using the ratio between the biochemical oxygen demand (BOD) and the chemical oxygen demand (COD). The results show that, in general, the elongation of the alkyl chain tends to increase the negative impact of the PILs towards the organisms and biological systems under study. According to these results, m-2-HEAA and m-2-HEAP are the less and most toxic PILs studied in this work, respectively. Additionally, all the PILs have demonstrated low biodegradability. [ABSTRACT FROM AUTHOR]

In this work, discrete quantum dots of crystallized anatase TiO 2 are successfully anchored on carbon nanosheets containing amorphous SiO 2 via templated self-assembly and pyrolysis routes. The novel hybrid photocatalyst of TiO 2 /C/SiO 2 exhibits well coupled adsorption and visible light photocatalysis on chlorpromazine (CPZ) and the rate constants are 0.0223 and 0.0198 min−1, respectively. The direct photocatalytic degradation of CPZ under static conditions reaches 91.1% within 3 h while a removal rate of 31.4% for CPZ could be retained under dynamic flow conditions, and the improved performance could be attributed to enhanced adsorption via SiO 2 /C and highly exposure of TiO 2 QDs surface. Based on the trapping experiments, ESR, LC-MS, and toxicity evaluation, O 2 − free radicals are identified as main reactive species for CPZ degradation along three possible pathways, with reduced toxicities for its intermediates. The cell viability tests of photocatalytic-degraded solutions and the catalyst exhibit negligible toxicities for both intermediates and the material, suggesting the novel composite of TiO 2 /C/SiO 2 as an environmental friendly photocatalyst for pharmaceutical wastewater treatment. [Display omitted] • Anatase quantum dots anchored on carbon lamellas as a biocompatible photocatalyst. • Pharmaceutical wastewater purification by coupled adsorption and photocatalysis. • Photocatalytic degradation pathways of CPZ and toxicities evolution of intermediates. • Cell viability assay assessment of CPZ photocatalytic degraded byproducts. [ABSTRACT FROM AUTHOR]

Chloromethylisothiazolinone (CMIT) has been extensively used as antimicrobial in cosmetics, detergents, wall paints, and anti-fouling products. To prevent the potential ecological and health risks, the degradation mechanisms and toxicity changes of CMIT by Vacuum-Ultraviolet/Ultraviolet (VUV/UV) irradiation were investigated in this study. VUV/UV irradiation showed better performance on CMIT degradation compared to sole UV photolysis. The removal efficiency of CMIT with photon fluence of 0.6 μEinstein/cm2 was 8% and 100% by UV or VUV/UV irradiation, respectively. Radical quenching experiments indicated that 254 nm photolysis, 185 nm photolysis, and •OH oxidation contributed to CMIT degradation during VUV/UV process, with fluence-based apparent rate constants of 0.16, 0.13, and 4.9 μEinstein−1cm2, respectively. The formation of H 2 O 2 during VUV/UV process increased to 0.7 mg/L at 4.5 min, and the concentration of •OH ranged within 1.0–3.8 × 10−12 M. The degradation of CMIT by VUV/UV irradiation in neutral condition was slightly higher than that in acidic and basic conditions. The removal efficiency of CMIT with reaction time of 2 min decreased from 92.2% to 34.3% when the concentration of HCO 3 −/CO 3 2− increased to 1 mM. The degradation of CMIT by VUV/UV irradiation in secondary effluents was lower than that in ultrapure water because of the •OH scavenging effects, but still 2.9 times higher than that by UV photolysis. Four main degradation mechanisms of CMIT were observed during VUV/UV process, including the oxidation of sulfur, addition of hydroxyl groups on the double-carbon-bond, demethylation on the nitrogen, and substitution of organochlorine atom by hydroxyl group. Based on the quantitative structure activity relationship analysis, most products of CMIT underwent complete detoxification to fish and daphnia. 40% of products still showed acute toxicity to algae, but most of them were less toxic than CMIT. [Display omitted] • VUV/UV irradiation outperformed UV photolysis for CMIT removal in wastewater effluent. • VUV/UV degraded CMIT by 185 nm photolysis, 254 nm photolysis and.•OH oxidation • The formation of hydrogen peroxide and hydroxyl radicals was quantified. • CMIT was degraded by dechlorination, N-demethylation, oxidation of sulfur and alkene. • Most products were partially or completely detoxified to fish, daphnia and algae. [ABSTRACT FROM AUTHOR]

Chlorpyrifos (CPF) is an extensively used organophosphorus pesticide. Recently, it has attracted increasing attention due to environmental health problems caused by it. Although numerous studies have discovered the dechlorinated photoproduct of CPF, its structure and toxicity remain largely unknown. In this study, we systematically investigated the structure and toxicity of dechlorinated photoproduct of CPF. The CPF degradation experiment was performed, and its products were identified by ultra high performance liquid chromatography-orbitrap fusion tribid mass spectrometer (UHPLC-Orbitrap Fusion TMS). Additionally, bond dissociation energy (BDE) calculations and photoproduct chemical synthesis were employed to determine the structure of dechlorinated photoproduct of CPF. The toxicity of CPF photoproduct was evaluated through the Ecological Structure Activity Relationships (ECOSAR) Class Program, the Toxicity Estimation Software Tool (T.E.S.T.) software, and acute toxicity testing. The results indicated that the dechlorinated photoproduct of CPF was identified as O,O-Diethyl-O-(3,5-dichloro-2-pyridyl) phosphorothioate (Dechloro-CPF), which was produced in large quantity within the first 30 min of photodegradation experiment. The acute and chronic toxicity values of Dechloro-CPF were obviously higher than those for the other two photoproducts. The median lethal dose (LD 50) of Dechloro-CPF was 31.6 mg/kg for female mice and 58.4 mg/kg for male mice. This study reveals the photodegradation mechanism of CPF and confirms that Dechloro-CPF was dechlorinated photoproduct of CPF with potential acute toxicity to aquatic species and mammalian (including human). Our findings will contribute to a more comprehensive risk evaluation of CPF in food and the environment. [Display omitted] • The dechlorinated photoproduct was generated in photolysis experiments of Chlorpyrifos. • The dechlorinated photoproduct of Chlorpyrifos was O,O-Diethyl-O-(3,5-dichloro-2-pyridyl) phosphorothioate (Dechloro-CPF). • The toxicity of Dechloro-CPF photoproduct was assessed. [ABSTRACT FROM AUTHOR]

The photolysis of amlodipine (AML) as a ubiquitous pollutant in natural water has been extensively studied. Montmorillonite (MMT), a major component of suspended particles in surface aquifers, plays key roles in the natural transportation and transformation of organic contaminants in the environment. However, literature has scarcely focused on whether and how suspended particles affect the phototransformation of AML. This study systematically investigated the phototransformation behavior of AML in MMT suspensions under simulated sunlight. The results obtained showed that MMT significantly enhanced the photolysis of AML. The photodegradation of AML in 0.05 g/L MMT suspension reached 92.2 % after 3 h irradiation under the simulated sunlight. The photodecomposition followed the pseudo-first-order kinetic with a rate constant of 0.803 h−1 in the presence of 0.05 g/L MMT, which is about 19 times larger than that in the absence of MMT (0.0421 h−1). Further mechanistic investigation suggested that MMT accelerated the photolysis of AML by the formation of surface complexes between cationic amino groups of AML and the negatively charged sites on MMT surface, which greatly facilitated light absorption and electron transfer for the production of cationic radical AML+·. Meanwhile, the hydroxyl radicals generated by irradiated MMT also played an important role in the photocatalytic degradation of AML. The probable photodegradation pathways of AML in MMT suspension further supported the proposed mechanisms. The toxicity evaluation of phototransformation products of AML with ECOSAR program indicated that photolysis could reduce its potential threats. These findings reveal an important and previously overlooked phototransformation mechanisms of AML in the presence of MMT clays, which is of importance in assessing the environmental fate of other similar organic contaminants. [Display omitted] • The photolysis of AML was accelerated in the presence of MMT. • MMT promoted the photolysis of AML by forming MMT-substrate surface complexes. • Dehydrogenation was found a main AML photodegradation pathways. • MMT promoted photodegradation significantly reduced the predicted toxicity of AML. [ABSTRACT FROM AUTHOR]

The incorporation of nanomaterials in binders in the paving area has been studied to improve the mechanical behavior of asphalt mixtures. However, asphalt mixture compounds are susceptible to leaching and deposition in the environment. In this context, this research aimed to investigate the toxic effect of two leachate extracts from asphalt mixtures nanomodified with 2% carbon nanotube and 3% organophilic nanoclay, compared to conventional mixture, using Daphnia magna and Landoltia punctata as test organisms. The nanomaterials were characterized to confirm morphology, stability and effective diameter. Extracts were chemically characterized using the Fourier-Transform Infrared Spectroscopy (FTIR) technique, which indicated presence of functional groups of the asphalt binder in greater intensity in the leachate from conventional mixture. Acute toxicity with D. magna indicated EC 50,48h of 83.5 ± 6.2 mL/L for leachate extract from conventional mixture, 306.0 ± 87.6 mL/L for leachate extract from mixture with nanoclay and 464.8 ± 32.1 mL/L for leachate extract from mixture with carbon nanotube. No leachate caused significant chronic toxicity. As for L. punctata , concentrations that caused 50% growth inhibition were 127.5 mL/L for the leachate extract from mixture with carbon nanotube, 196.9 mL/L for the leachate extract from mixture with nanoclay and 205 mL/L for the leachate extract from conventional mixture. For these test organisms, there is no evidence of negative impacts directly associated with the use of the present nanomaterials in asphalt mixtures. The incorporation of these nanos may also reduce the acute toxicity of the mixtures. [Display omitted] • The extracts of the nanomodified mixtures have lower acute toxicity (Daphnia magna). • No leachate showed significant effects on chronic toxicity (Daphnia magna). • All leachate extracts have a low degree of toxicity to the macrophyte. • Carbon nanotube and nanoclay can reduce the toxicity of asphalt mixtures. [ABSTRACT FROM AUTHOR]

Distillery wastewater has significant amount of coloring compounds and organic substances even after the secondary treatment process, which poses many severe environmental and health threats. However, the recalcitrant coloured compounds have not yet been clearly identified. In this study, two bacterial strains DS3 and DS5 capable to decolorize distillery wastewater (DWW) pollutants were isolated and characterized as Staphylococcus saprophyticus (MF182113) and Alcaligenaceae sp. (MF182114), respectively. Results showed that mixed bacterial culture was found more effective decolorizing 71.83% DWW compared to axenic culture DS3 and DS5 resulting only 47.94% and 50.67% decolorization, respectively. The FT-IR and LC-MS/MS analysis of untreated DWW showed the presence of many recalcitrant compounds having different functional groups, but after bacterial treatment, most of compounds get diminished and the toxicity of DWW was reduced significantly. Further, the Nile red staining of Caenorhabditis elegans exposed to untreated and bacteria treated DWW for evaluation of toxicity assay and results revealed that the worms exposed to untreated DWW showed sharp reduction in total fat content having more profound effects, suggesting the diminished nAchR signaling as compare to bacterial treated DWW. Hence, this study revealed that inadequate disposal of untreated DWW may cause transfer of toxic substances into the environment and receiving water bodies. Image 1 • Distillery wastewater has a variety of chemical pollutants. • Bacteria Staphylococcus saprophyticus and Alcaligenaceae sp. were used to treat DWW. • FT-IR and LC-MS used to characterize the DWW pollutants and their metabolites. • Toxicity of DWW pollutants and metabolites was evaluated by Caenorhabditis elegans. • Study showed disposal of untreated DWW may cause severe environmental pollution. [ABSTRACT FROM AUTHOR]

Sulfite-based photocatalysis has been recently employed as a promising technology for the treatment of organic pollutants via the generation of reactive radicals. In this contribution, the effect of wastewater matrix constituents and toxicity evaluation were systematically investigated in the FeIII impregnated N-doped TiO 2 (FeN–TiO 2)/sulfite/visible LED (Vis LED) process in the presence of diphenamid (DPA) as a model organic pollutant. The results showed that the presence of HCO 3 −, SO 4 2−, NO 3 −, and F− had no detrimental effect on DPA degradation. Conversely, the presence of Cr(VI), NO 2 −, Cl−, and Br− caused a stronger retardation effect. The effect of natural organic matter such as humic acid (HA) was inert at normal concentrations. Interestingly, the retardation effect of inorganic ions can be quantified at any given ion concentration based on the linear correlations between the DPA decay (first-order kinetic constants) and concentration of ion species. Toxicity tests on Synechocystis sp., Microcystis flos-aquae, and Nostoc sp. algae revealed that higher toxicity was noticed at 240 min treatment time accompanied by lower toxicity with prolonging the treatment time for all selected algae except for Microcystis flos-aquae. In addition, novel two-phase mathematical models were successfully proposed to predict the accumulation of intermediates depending on their evolution profile. • The presence of HCO 3 −, SO 4 2−, NO 3 −, and F− had no adverse effect on DPA decay. • The presence of Cr(VI), NO 2 −, Cl−, and Br− caused a strong inhibition effect. • A linear correlation between the DPA decay and ion concentration was achieved. • Toxicity of DPA and its intermediates on algae was the highest at 240 min. • Accumulation of DPA's intermediates was predicted using a novel two-phase model. [ABSTRACT FROM AUTHOR]

The search for a suitable heterogeneous catalyst in peroxymonosulfate (PMS) activation holds tremendous promise for the degradation of organic pollutants. Two-dimensional (2D) transition metal dichalcogenides such as WS 2 exhibit broad applications in heterogeneous catalysis, and we first extended its application in PMS activation in this work. It was found that WS 2 could efficiently activate PMS resulting in the degradation of diclofenac (DCF). The results show that the PMS offers direct oxidation, and WS 2 could initiate PMS to produce singlet oxygen (1O 2) and superoxide radical (·O 2 −). This resulted in the improved removal of DCF in the WS 2 /PMS system. Furthermore, the degradation pathway of DCF was proposed according to the detected intermediates/products and density functional theory (DFT) calculation. Degradation intermediates and the evaluation of product toxicity indicated that the developed WS 2 /PMS system was a safe and detoxifying process while also offering efficient DCF removal. This study offers more insight into the development of suitable materials for the activation of PMS and gives clear direction for the degradation of DCF and its toxic intermediates. Image 1 • 2D WS 2 nanosheet is first used for the activation of peroxymonosulfate (PMS). • WS 2 /PMS system show high efficiency towards diclofenac (DCF) degradation. • The degradation mechanism and pathways of DCF are proposed by DFT and LC-TOF-MS. • The exposure toxicity of intermediate indicates a safe detoxifying process by WS 2 /PMS. [ABSTRACT FROM AUTHOR]