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The composition of atmospheric particulate matter, including particle-bound polyaromatic hydrocarbons, generally shows a clear seasonal pattern which is reflected in its ecotoxicity as well. This study aimed at characterising seasonal differences in the ecotoxicity of rural aerosol samples applying both luminescent bacteria and higher plants as test organisms. Higher plant phytotoxicity was assessed by the Sinapis alba root growth inhibition test and the Vegetative Vigour Test. Different bioassays and end-points showed different sensitivity: while the Sinapis alba assay showed no toxic effect, luminescent bacteria proved an excellent screening tool, detecting no toxicity in the summer sample and the highest inhibition in the winter sample, with EC20 = 9.87%. In the case of Vegetative Vigour Test, parallel application of different end-points revealed that atmospheric particulate matter might have a Janus-faced effect: stimulation of photosynthetic pigments due to nutrient content and growth impairment due to toxic components.

The intensive development of medical science has led to an increase in the availability and use of pharmaceutical products. However, nowadays, most of scientific attention has been paid to the native forms of pharmaceuticals, while the transformation products (TPs) of these substances, understood herein as metabolites, degradation products, and selected enantiomers, remain largely unexplored in terms of their characterization, presence, fate and effects within the natural environment. Therefore, the main aim of this study was to evaluate the toxicity of seven native compounds belonging to different therapeutic groups (non-steroidal anti-inflammatory drugs, opioid analgesics, beta-blockers, antibacterial and anti-epileptic drugs), along with the toxicity of their 13 most important TPs. For this purpose, an ecotoxicological test battery, consisting of five organisms of different biological organization was used. The obtained data shows that, in general, the toxicity of TPs to the tested organisms was similar or lower compared to their parent compounds. However, for example, significantly higher toxicity of the R form of ibuprofen to algae and duckweed, as well as a higher toxicity of the R form of naproxen to luminescent bacteria, was observed, proving that the risk associated with the presence of drug TPs in the environment should not be neglected. Electronic supplementary material The online version of this article (10.1007/s11356-020-08881-3) contains supplementary material, which is available to authorized users.

Wastewater from pharmaceutical and related industries contains many residual pharmaceutical components rich in color and high COD contents, which cannot be removed through the traditional wastewater treatment processes. Recently, microbial electrolysis ultraviolet cell (MEUC) process has shown its promising potential to remove recalcitrant organics because of its merits of wide pH range, iron-free, and without complications of iron sludge production. However, its application to the real pharmaceutical-rich industrial wastewater is still unknown. In this study, the MEUC process was validated with real ciprofloxacin-rich (6863.79 ± 2.21 µg L−1) industrial wastewater (6840 ± 110 mg L−1 of COD). The MEUC process achieved 100% removal of ciprofloxacin, 100% decolorization, and 99.1% removal of COD within 12, 60 and 30 h, respectively, when it was operated at pH-controlled at 7.8, applied voltage of 0.6 V, UV intensity of 10 mW cm−2, and cathodic aeration velocity of 0.005 mL min−1 mL−1. Moreover, fluorescence analysis showed that protein- and humic-like substances in such wastewater were effectively removed, providing further evidence of its high treatment efficiency. Furthermore, eco-toxicity testing with luminescent bacteria Vibro Feschri confirmed that the treated effluent was utterly non-toxic. The results demonstrated the broad application potential of MEUC technology for treating industrial wastewater.

A comprehensive workflow for suspect screening and non-target screening with gas chromatography coupled with quadrupole time-of-flight mass spectrometry (GC/QTOF-MS) was used to characterize the pollution characteristics of soil samples in a typical coking plant in China. Suspect screening confirmed 57 chemicals including PAHs, alkyl PAHs, and phthalates contained in high-resolution personal compound database and library (PCDL). Non-target screening detected 88 chemicals from soil samples in the NIST 17 library. A total of 122 chemicals were screened in soil samples, and many of them were of emerging concern. Their presence in the soil obtained from coking operations has been underestimated, such as the oxygenated PAHs (naphtho[2,1-b]furan and 9H-fluoren-9-one), and the alkyl biphenyls compounds (4,4′-dimethylbiphenyl, 3,3′-dimethylbiphenyl, 4-methyl-1,1′-biphenyl and 2,2′,5,5′-tetramethyl-1,1′-biphenyl). Toxicity assays by luminescent bacteria proved that the extracts from soil samples at different depths showed varying toxicity to V. qinghaiensis sp.-Q67. Soil extracts from a depth of 20–40 cm exhibited the greatest toxicity to luminescent bacteria compared with the other six-layered soil samples, which was correlated with the number of detectable pollutants and total organic carbon content. This study provided a screening method for suspect and non-target contaminants in urban industrial soil sites, which was important in identifying localized contamination sources.

Organic ligands are commonly believed to decrease the toxicity of metal ions, but there is few experimental evidence, especially for chromium (Cr(III)), which often coexists with organic compounds in industrial effluents. Here, the complexation of Cr(III) with acetate, lactate, l-tartrate, biphthalate and oxalate was tested under the conditions of a toxicity test, with high ion strength, by spectroscopic techniques. The stability constants of the complexes were found to follow the order Cr(III) oxalate > Cr(III) lactate > Cr(III) biphthalate > Cr(III) L-tartrate > Cr(III) acetate. Then, aquatic toxicity of Cr(III) to Photobacterium phosphoreum for a 15-min exposure period was tested in the absence and presence of organic ligands. Results unexpectedly show that the complexation of Cr(III) with acetic, lactate, l-tartrate and biphthalate resulted in enhanced toxicity to luminescent bacteria, whereas the coordination of Cr(III) with oxalate sharply alleviated the toxicity of individual oxalate and inorganic Cr(III), which was further confirmed by the scanning electron microscopy (SEM). Our findings show thus that organics do not always mitigate the toxicity of Cr(III) in acidic water.

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.

Diclofenac was frequently found in various waters, indicating conventional wastewater treatment methods ineffective in its removal. In this study, LaFeO3 (LFO) was synthesized and its catalytic activity of LFO as the activator of different oxidants such as persulfate (PS), hydrogen peroxide and peroxylmonosulfate (PMS) was evaluated in terms of DCF degradation. The influence of calcination temperature was examined on the catalytic activity of LFO. The effects of various parameters including pH levels, PMS concentration, LFO dose and initial DCF concentration were investigated on DCF degradation rate. The marginal effects of PMS concentration and LFO dose were compared. Langmuir-Hinshelwood (LH) model was used to quantitatively describe DCF degradation reaction in LFO/PMS system. The two constants, k (Limiting reaction rate at maximum coverage) and K (Equilibrium adsorption constant), were determined on the basis of LH model. The performance of LFO/PMS process was also estimated in the presence of various inorganic anions. The potential toxicity of LFO and PMS were evaluated using phytoplankton and the toxicity evolution during DCF degradation was also investigated using luminescent bacteria. This contribution provides a basic study regarding the potential application of heterogeneous PMS activation by perovskite LFO for both DCF removal and toxicity elimination.

It has been proven that the raw wastewater, secondary effluent and even reclaimed water may have toxic effects on aquatic organisms. In the present study, fractionation procedures combined with bioassays using luminescent bacteria were conducted to identify the fractions that contributed to the acute and long-term toxicity of municipal wastewater. Solid phase extraction was used to divide dissolved organic matter from the wastewater into three fractions, including non-polar, medium-polar and polar fraction. Among these fractions, although the acute toxicity of municipal wastewater was mainly caused by polar and medium-polar chemicals, the acute toxicity induced by the unit mass of the medium-polar fraction was the greatest. Using three kinds of resins, the organic substances in municipal wastewater were classified into six fractions, and the long-term toxicity of these fractions was further identified. The long-term toxicity of the hydrophobic neutrals, which were the primary toxic substances in raw wastewater, decreased after the conventional secondary biological treatment. Hydrophilic neutrals, which accounted for the majority of organic substances in the secondary effluent, were the main substances with long-term toxicity in the secondary effluent. The identification of fractions with acute and long-term toxicity in municipal wastewater is beneficial for further treatment to attenuate the ecotoxicity of wastewater before discharge into the aquatic environment.

Due to their widespread use and harmful effects on aquatic environment, sulfonamide antibiotics (SAs) have become an emerging pollutant of great concern around the world. In this study, we investigated the degradation process and mechanism of sulfamerazine (SMR), sulfadiazine (SDZ), and sulfapyridine (SPD) by electron-beam irradiation (EBI). The results showed that the three SAs were well suited to the pseudo-first-order reaction kinetics, and they could be almost completely removed with high efficiency (5 kGy). Among the environmental factors, pH (3.0) and O2 atmosphere can further enhance the removal of the sulfonamides (SAs), while NO2− has the most pronounced degrading inhibitory effects among the many ions, these results illustrate that hydroxyl radicals play a dominant role. Compared with SMR and SDZ, the degree of mineralization of lower molecular weight SPD is obvious (45%). LC-MS and DFT calculations indicate that the concentrations of degradation products of the three SAs show a tendency to increase and then decrease, demonstrating that EBI can achieve efficient removal and further mineralization of SAs. Meanwhile, the results of the common product 4-Aminophenol produced during the degradation process further indicate that HO is the predominant reactive oxygen species (ROS). In addition, acute toxicity experiments with luminescent bacteria and predictions of ECOSAR procedures proved the toxic effects greatly decreased after the degradation. This study provides new ideas for achieving efficient and profound removal of emerging pollutants from the aquatic environment.

This study evaluated the acute effects of nine different production chemicals typically employed in oil exploration on the toxicity of a synthetic produced water (PW). Bioassays with the Microtox® System were performed to monitor changes in the level of light emission of the marine luminescent bacteria Vibrio fischeri during exposure to the samples. The results show that synthetic PW is moderately toxic to these organisms, and the addition of oilfield chemicals significantly increases its toxicity. For most of the additives tested, the toxicity of the aqueous phase following partitioning against crude oil was not strongly altered by the presence of these chemicals. Synergistic effects occurred in the three different mixtures investigated. Among the additives studied, biocide, corrosion inhibitor, H2S scavenger, and surfactant were the most toxic for V. fischeri. Furthermore, the surfactant has been identified as the possible source of the acute toxicity observed.

In this paper, the releasing characteristics and biological toxicity of Tl, Hg, As and Sb in waste of Lanmuchang mercury-thallium mine were studied. The results indicated that strong acidity can significantly promote the release of Tl from waste. With the increase of pH, the release of Sb grew steadily, while Hg and As showed a trend of first increasing and then decreasing. Fe2(SO4)3 contributed less to the release of As and Sb than to that of Hg and Tl. FeCl3 significantly inhibited the release of As, Sb and Tl. In the leaching experiments of litter and root exudates, the lixiviums appeared neutral, and the litter and root exudates solution significantly reduced the release of Tl, and showed less toxicity to luminescent bacteria. However, they promoted the release of Hg, As and Sb at different levels.

Protecting the quality of lake watersheds by preventing and reducing their contamination is an effective approach to ensure the sustainability of the drinking water supply. In this study, acute toxicity assessment was conducted on the basis of acute bioluminescence inhibition assay using the marine bacterium Vibrio fischeri as the test organism and Luoma Lake drinking water source in East China as the research target. The suitable ranges of environmental factors, including pH value, organic matter, turbidity, hardness, and dissolved oxygen of water samples were evaluated for the toxicity testing of bioluminescent bacteria. The physicochemical characteristics of water samples at the selected 43 sites of Luoma Lake watershed were measured. Results showed that the variations in pH value (7.31–8.41), hardness (5–20 °d) and dissolved oxygen (4.44–11.03 mg/L) of Luoma Lake and its main inflow and outflow rivers had negligible impacts on the acute toxicity testing of V. fischeri. The luminescence inhibition rates ranged from −11.21% to 10.80% at the 43 sites. Pearson’s correlation analysis in the experiment revealed that temperature, pH value, hardness, and turbidity had no correlation with luminescence inhibition rate, whereas dissolved oxygen showed a weak statistically positive correlation with a Pearson correlation coefficient of 0.455 (p < 0.05).

Trans-resveratrol becomes more and more popular all over the world as a powerful antioxidant. Since its positive properties, including antioxidant, anti-inflammatory, anti-tumor are indisputable, nowadays trans-resveratrol is used as a component of various products from nutriceutics to body care formulations, where it is supposed to behave as natural antioxidant and anti-aging compound. It is also added to food packaging materials to increase their stability or/and prevent oxidation. Nevertheless, being released to the environment resveratrol easily forms various transformation products with potentially negative environmental and health effects. The present paper deals with transformation of pure resveratrol and its formulation used as UV-protectors in conditions of aquatic chlorination. Over 80 transformation products were tentatively identified using gas chromatography-high resolution mass spectrometry (GC-HRMS) and ultra pressure liquid chromatography-high resolution mass spectrometry (UPLC-HRMS). Chlorinated phenols and biphenyls are the most relevant among them. Estimation of toxicity of resveratrol products was carried out using luminescent bacteria V. fischeri tests.

Doxazosin (DOX), a selective alpha blocker, is widely used in medical therapy as an effective antihypertensive agent. It is a frequently prescribed drug and for this reason, environmental and ecotoxicological research is of great importance in terms of exposure and risk for both aquatic species and humans. In this study we focused on photolytic and TiO2 photocatalytic degradation processes of doxazosin under different simulated conditions, with the emphasis on identification of degradation products. Photolytic (without TiO2) experiments were performed in the presence and absence of oxygen, while photocatalytic degradation of doxazosin aqueous solution has been carried out under constant oxygen flow. DOX degradation was more efficient in the TiO2/UVA photocatalytic experiment than during photolytic processes (UVA and UVC, UVC-N2). LC-HRMS analyses with electrospray ionization allowed observing the formation of several major degradation products depending on the reaction conditions (presence or absence of oxygen, photocatalysis). The transformation products were identified based on exact mass measurements, isotopic distribution, and fragmentation pattern. Among them, dominated C17H21N5O3 and C17H23N5O4 (cleavage of the dioxane cycle), and C23H25N5O7 (hydroxylation). The detailed degradation pathway has been proposed. Toxicity testing with V. fischeri luminescent bacteria revealed higher toxicity of samples in photolytic rather than photocatalytic experiments which might be attributed to the formation of different products.

In this study, a biosensor is designed to remove mercury as a toxic metal contaminant from the soil. The rhamnolipid biosurfactant was used to extract the mercury sorbed to soil to the aqueous phase. An immobilized bioluminescent bacterium (Escherichia coli MC106) with pmerRBPmerlux plasmid is assisted for mercury detection. A significant decrease in luminescence level was observed in a biosensor system containing contaminated soil sample extract. The concentrations of extracting mercury are well correlated with the mercury toxicity data obtained from experimental biosensor systems according to the RBL value. The optimum aeration rate of 20 ml/min was obtained for the biosensor systems. The advantage of such a biosensor is the in situ quantification of mercury as a heavy metal contaminant in soils. Therefore, this system could be proposed as a good biosensor-based alternative for future detection of heavy toxic metals in soils.

The production of biodegradable plastics is considered to be a way to reduce plastic waste issue. Among others, oxo-degradant additives enable a faster degradation of plastics in the environment. However, the introduction of these new materials could provoke the release of substances potentially toxic in the environment. This work determined and compared the toxicity of leachates from various additivated polymers (polyethylene, PE; polypropylene, PP; polystyrene, PS) upon different test organisms: plants (Sorghum saccharatum, Lepidium sativum, Sinapis alba, and Vicia faba), crustacean (Daphnia magna), and luminescent bacteria (Vibrio fischeri). Daphnia magna survival was mainly affected by PS and PP leachates (72% and 61% effect, respectively) while PS notably reduced the reproduction rate. On plants, only PP exerted a negative effect (S. saccharatum IG% 32.4), while V. fischeri always showed values around 50%. The data integration, through the Toxicity Test Battery Integrated Index (TBI) approach, allowed to rank the leachates toxicity as PE > PS > PP. This result could be mainly ascribable to the highest metals content in PE since no difference with organic compounds analysis was evidenced. In conclusion, since the polymers exerted dissimilar toxicity, the additive could not be considered the sole responsible of the measured toxicity, but its role in the enhancement of the virgin polymers leachates effects can be solidly hypothesized.

The aim of the study was ecological risk assessment (ERA) of the agricultural soils located in the vicinity of the highly industrialized area and exposed to different emission sources of polycyclic aromatic hydrocarbons (PAHs). In this study, we demonstrated the combination of generic and site-specific ERA approach for screening assessment and delineation of the area of a high ecological risk. Generic approach was based on a hazard quotient and indicated that 62% of the research area needs further assessment. For site-specific evaluation, the Triad approach was utilized. Information from three lines of evidence (LoE): chemical, ecotoxicological and ecological, was integrated into one environmental risk (EnvRI) index. The chemical risk was derived from toxic pressure coefficients based on the total PAHs concentration. The ecotoxicological LoE included an acute toxicity testing: the luminescent bacteria Aliivibrio fischeri activity in both liquid- and solid-phase samples and the ability of crustacean Thamnocephalus platyurus to food uptake. The ecological LoE comprised microbial parameters related to soil respiration and enzymatic activity. Integrated EnvRI index ranged from 0.44 to 0.94 and was mainly influenced by high values of chemical LoE risk, while the ecotoxicological and ecological LoE indicated no or low risk. Due to the relatively high uncertainty associated with the contradictory information given by LoEs, there is the need to confirm potential risk in a tier 2 analysis.

It has been stated by researchers that the antibiotic polymyxin B sulfate (POL) is a key component inducing time-dependent antagonism in freshwater luminescent bacteria, Vibrio qinghaiensis sp.-Q67, exposed in the ternary mixture system of the ionic liquids, pesticide and antibiotics. However, the previous statement is limited to ternary and quaternary mixtures without considering situations such as the binary system. In order to prove the direct inducing of antagonism by POL in a more complete and systematic way, two categories of experiments (adding POL in non-antagonistic ternary system and decomposing antagonistic ternary system with POL into the binary system) have been conducted in this paper. The results showed that quaternary mixture systems (adding POL to non-antagonism ternary mixture, up verification) exhibit antagonistic action in a majority of rays, at some point in the experiment. However, by decomposing the antagonistic ternary mixtures with POL into binary mixtures (down verification), the combined toxicities of binary mixtures at all time points in the experiment are additive. Obviously, the POL has a significant contribution to antagonism only in the ternary and quaternary mixtures, but not in the binary mixtures. We can draw a new conclusion that the antagonism of the multi-component mixtures is induced by at least three components (including POL), with complex chemical interactions. Therefore, considering POL's influence of antagonism as an example, future environmental protection practitioners and academic researchers should construct more scenarios of mixtures when assessing the influences and reactions of certain chemicals causing pollutions.

In this study, the applicability of UV absorbance at 254 nm (UV254) and volatile fatty acids (VFAs) to serve as reliable surrogates to predict acute toxicity of traditional Chinese medicine (TCM) wastewater was investigated. The medicine residues and VFAs were identified as main components of the TCM wastewater, and their individual and joint toxicity assays were operated with luminescent bacteria. The median effective concentration (EC50) values of medicine residues and VFAs were in the range of 26.46-165.55 mg/L and 11.45-20.58 g/L, respectively. The joint toxicity action modes of medicine residues, VFAs and medicine residues-VFAs were identified as additive, additive and synergistic respectively. UV254 and VFAs showed better correlations with acute toxicity according to the correlation analysis, compared with other conventional parameters. The regression model was a good fit for toxic unit (TU50) as a function of UV254 and VFAs according to the stepwise regression method (adjusted R2 = 0.836). Validation of the model to the pilot-scale samples provided satisfactory prediction results in the influent and hydrolysis acidification effluent samples tests, but for EGSB effluent and final effluent samples, the model needed further optimization. Surrogates prediction using UV254 and VFAs provided a valuable and cost-saving tool for rapid or on-line monitoring of acute toxicity of TCM wastewater.

There is a need for rapid simple and informative environmental assessment methods. The present investigation is aimed at assessing the possibility of using the combined enzyme system of luminescent bacteria: NAD(P)H:FMN-oxidoreductase + luciferase (Red + Luc) for predicting the potential toxicity of industrial urbostratozems sampled in the city of Krasnoyarsk. Three groups of urbostratozems polluted with fluorine, arsenic and lead, were tested by the methods of chemical analysis and enzymatic bioassay. Only the assessment of the arsenic-contaminated soil samples showed the dependence between the reduced activity of the enzyme system and the arsenic concentration variations. The results reveal that the sensitivity of the Red + Luc enzyme system to the soil pollutants depends on the properties of the studied soil samples. Moreover, the solubility of lead in the soil samples affects the accuracy of the enzymatic bioassays for soil toxicity testing. The results of the enzymatic bioassay of the fluoride-contaminated soil samples are ambiguous. The obtained data show the relevance of the sample preparation during integral bioassays. In addition, soil properties should be taken into account as well. The current study emphasizes the importance of conducting chemical and biological testing as a combined set to obtain comprehensive information about the anthropogenic load.

Advanced oxidation processes (AOPs) have been widely applied for the advanced treatment of recalcitrant wastewater. However, the toxicity changes during AOPs are still unclear because in some cases the intermediate products could exhibit equivalent or even higher toxicity compared with the original pollutants. Therefore it is necessary to evaluate the toxicity evolution during AOPs. This review mainly focused on the toxicity changes of wastewater during various AOPs treatment, including Fenton/Fenton-like oxidation, ozonation/catalytic ozonation, persulfate radical-based oxidation, photocatalytic oxidation, ionizing radiation, electro-catalytic oxidation, ultrasound oxidation and wet oxidation. Firstly, the toxicity assessment methods were summarized, including acute toxicity (such as luminescent bacteria assay, fish assay, water flea assay and algae assay), genetic toxicity (Ames assay, SOS/umu assay, comet assay and micronucleus assay), estrogenic activity, immunity toxicity, and endocrine disrupting effect (such as yeast two-hybrid assay and fish endocrine disrupting assay), the applications of these methods in determining the toxicity changes of wastewater during AOPs treatment were summarized and analyzed in detail. Secondly, the toxicity prediction by computational simulation was introduced, mainly focusing on two common software, including TEST and ECOSAR. Thirdly, the strategies for eliminating the toxicity of wastewater after AOPs treatment were proposed. Finally, the concluding remarks and perspectives were presented for further study. This review will deepen to understand the toxicity evolution of wastewater during AOPs.

Additional control indexes should be considered for the operation and design of post-treatment systems, as the wastewater treatment objectives are developing toward protecting the safety of ecological environments. In this study, two control indexes were selected and examined systematically in pilot-scale shallow open-water unit (SOWU) ponds for domestic effluent polishing: micropollutants and biotoxicities. The total risk quotient (RQTotal ≤ 1) and effect-based trigger value (EBT) were set as the thresholds for known micropollutants and biological effects, respectively. The results showed that RQTotal of micropollutants (n = 46) could be mitigated to an acceptable level and the luminescent bacteria toxicity was in compliance with the EBT after SOWU polishing in the warm season. The reduction of micropollutants and biotoxicities in the SOWUs both fit the k–C* model well (R2 > 0.9) in the warm and cold seasons. Finally, the k–C* model integrated with the control indexes was developed to design the SOWU dimensions, and the results indicated that a pond area of 21.7–108.5 m2 was required for every 1 m3/d of effluent when micropollutants were set as the control index, while a pond area of 3.6–18.2 m2 was required when luminescent bacteria toxicity was set as the control index.

The evaluation of the ecotoxicological effects of water pollutants is performed by using different aquatic organisms. The effects of seven compounds belonging to a class of widespread contaminants, the benzo-fused nitrogen heterocycles, on a group of simple organisms employed in reference ISO tests on water quality (unicellular algae and luminescent bacteria) have been assessed to ascertain their suitability in revealing different contamination levels in the water, wastewater, and sediments samples. Representative compounds of benzotriazoles, benzothiazoles, and benzenesulfonamides, were tested at a concentration ranging from 0.01 to 100 mg L−1. In particular, our work was focused on the long-term effects, for which little information is up to now available. Species-specific sensitivity for any whole family of pollutants was not observed. On average, the strongest growth rate inhibition values were expressed by the freshwater Raphidocelis subcapitata and the marine Phaeodactylum tricornutum algae. R. subcapitata was the only organism for which growth was affected by most of the compounds at the lowest concentrations. The tests on the bioluminescent bacterium Vibrio fisheri gave completely different results, further underlining the need for an appropriate selection of the best biosensors to be employed in biotoxicological studies.

In the last decades, there has been an increasing concern about the human exposure to indoor dust. Therefore, it is imperative to assess the toxicity of indoor dust and associated dust extracts. In this study, the acute toxicity assessment of indoor dust was performed using a bioluminescence test, with Photobacterium phosphoreum T3 (PPT3) chosen as the test bacterium. The different indoor dust samples were collected from residences, offices, dormitories and laboratories in Shanghai, China. Our data reveal that PPT3 is more active to water-soluble ions and organic contaminants at low concentrations, while extract solutions elicit increased bacterial toxicity at high concentrations. The results of a bioluminescence assay by PPT3 indicated that the dust organic extracts exhibited increased toxicity compared with the water exacts. Dust extracts from the laboratory exhibited the greatest bacterial toxicity when compared with office, dormitory and residence samples. Moreover, office dust exhibited higher bacterial toxicity than residence dust. Furthermore, the comprehensive toxicity of dust on PPT3 was assessed by extracts toxicity -addition (i.e. IRaddition). The calculated values were close to the corresponding experimental data. The bioluminescence test showed the indoor dust samples are weakly toxic to PPT3, which are equivalent to 0.046–0.123 mg Hg•L−1. Different dust extracts among the different sampling sites showed varying toxicity to PPT3. This study provides some important information to understand the potential health risk from different indoor environment using a rapid bioluminescence assay.

Although magnetic ionic liquids (MILs) are not yet industrially applied, their continued development and eventual commercial use may lead to their appearance into the aquatic ecosystem through accidental spills or effluents, consequently promoting aquatic contaminations. Furthermore, the deficient information and uncertainty surrounding the environmental impact of MILs could be a major barrier to their widespread industrial application and international registration. Thus, in the present work, a range of cholinium salt derivatives with magnetic properties was synthesized and their ecotoxicity was evaluated towards the luminescent bacteria Vibrio fischeri. The results suggest that all MILs structures tested are moderately toxic, or even toxic, to the bacteria. Furthermore, their toxicity is highly dependent on the structural modifications of the cation, namely the alkyl side chain length and the number of hydroxyethyl groups, as well as the atomic number of the metal anion. Finally, from the magnetic anions evaluated, the [MnCl4]2- is the less toxic. In order to improve the knowledge for the prospective design of environmentally safer MILs, it is important to expand this study to other aquatic organisms at different trophic levels. published

Chlorination is essential to the safety of reclaimed water; however, this process leads to concern regarding the formation of disinfection byproducts (DBPs) and toxicity. This study reviewed the formation and control strategies for DBPs and toxicity in reclaimed water during chlorination. Both regulated and emerging DBPs have been frequently detected in reclaimed water during chlorination at a higher level than those in drinking water, indicating they pose a greater risk to humans. Luminescent bacteria and Daphnia magna acute toxicity, anti-estrogenic activity and cytotoxicity generally increased after chlorination because of the formation of DBPs. Genotoxicity by umu-test and estrogenic activity were decreased after chlorination because of destruction of toxic chemicals. During chlorination, water quality significantly impacted changes in toxicity. Ammonium tended to attenuate toxicity changes by reacting with chlorine to form chloramine, while bromide tended to aggravate toxicity changes by forming hypobromous acid. During pretreatment by ozonation and coagulation, disinfection byproduct formation potential (DBPFP) and toxicity formation potential (TFP) occasionally increase, which is accompanied by DOC removal; thus, the decrease of DOC was limited to indicate the decrease of DBPFP and TFP. It is more important to eliminate the key fraction of precursors such as hydrophobic acid and hydrophilic neutrals. During chlorination, toxicities can increase with the increasing chlorine dose and contact time. To control the excessive toxicity formation, a relatively low chlorine dose and short contact time were required. Quenching chlorine residual with reductive reagents also effectively abated the formation of toxic compounds.

Phthalates has been widely used in children's toys as plastic plasticizers and softeners. The aim of this study was to extract chemically phthalates from 20 toy samples and determine toxicity using the Vibrio fischeri luminescent bacteria test. Subsequently the (the concentration producing 50% of maximal effect) was employed to characterize the toxicity of the sample and select the appropriate solvent from methanol, ethanol or glycerol in order to assess the adverse effects of di-n-butyl phthalate (DBP) or di-2-ethylhexyl phthalate (DEHP) and not solvent interference on Vibrio fischeri. Data showed that toxicity of glycerol was relatively low when the concentration was less than 0.44 mol/L. Therefore glycerol was selected as solvent. DBP and DEHP produced toxicity on Vibrio fischeri in the order of DEHP > DBP. The was 0.437 and 0.182 mol/L, respectively. This study provides the foundation for examination of combined toxic effects of the mixture of DBP and DEHP on Vibrio fischeri which is of signif...

Biological effects and ecotoxicity of NPs CeO2 with particle size Δ50 =16 nm and hydrobionts tolerance was measured in simulation based on test-reactions of a group of organisms representing major trophic levels of aquatic ecosystem. Biological activity of NPs CeO2 was noted against bacterial biosensor Ekolum, Сhlorella v. B.,Parameciumc., Daphniam. S. and Danior. Toxicity and hazard level of NPs CeO2 were measured using biotesting and hydrobionts. Toxicity of NPs CeO2 against luminescent bacteria Ekolum and Parameciumc. and Danior. was not established (L(E)С50 > 100 mg/l). In accordance with SGS and EC 93/67/EEC, NPs CeO2 is considered highly toxic (acute toxicity Level 1). Biomarkers and NPs CeO2 tolerant hydrobionts were determined. Range of tolerance of hydrobionts to NPs was established. The upper limit of tolerance was determined for certain hydrobionts by values of L(E)С50: 0.009 mg/l (by volume of Chl a) for Сhlorella v. B. and 46.15 mg/l (by mobility) for Daphniam. S.

Environmentally persistent free radicals (EPFRs) are detected in the clay, mineral or humic part of the soil, especially in soil contaminated with phenolic compounds. To clarify the detailed information on the formation of EPFRs, we used the contaminated soil with catechol to mimic their formation process in laboratory scale and tested their biotoxicity with luminescent bacteria (Photobacterium phosphoreum, P. phosphoreum). Our results showed that the concentration of EPFRs reached the maximum at pyrolysis temperature of 300 °C, and EPFRs could significantly inhibit the luminescence of P. phosphoreum. Based on the detection of OH radicals in the aquatic system we used, we speculated that the generation of OH may be a crucial contributor to the toxicity of EPFRs. Our results aid to understand the detailed process on the formation of EPFRs in contaminated soil, as well as the basic biotoxicity data of EPFRs, which will be helpful and essential for their potential environmental risk assessments.

The removal of acetaminophen (AAP) in aqueous solution by the UV/chlorine process was evaluated. The effect of chlorine dose, the initial AAP concentration, pH value, and UV intensity on the reaction were also investigated. The degradation mechanism and the ecological risk were further discussed. The results indicated that AAP degradation fitted pseudo-first-order kinetics. Compared with UV alone or dark chlorination, the combination of UV and chlorine significantly accelerated the degradation process. The AAP degradation was positively affected by chlorine dose and UV intensity, while negatively affected by the initial AAP concentration and ammonia nitrogen concentration during the UV/chlorine process. The frontier orbital theory analysis shows that the C5 position in the benzene ring of AAP is likely to be the first site attacked by HO• and Cl• radical to form the products. Twelve intermediates were identified by Q-TOF and GC-MS. The possible degradation pathways were also proposed. Luminescent bacteria experiment and ECOSAR prediction both revealed that acute toxicity of AAP degradation could only be partially reduced. Ecological risks during the UV/chlorine process need to be further evaluated.

The real antibiotic industrial wastewater with the characteristics of complex compositions, biological toxic, and degradation-resistant, is still biologically toxic to the ecosystem and human health even if the discharge standards have been met after treatment by traditional methods. Therefore, the biological harmless treatment of real antibiotic industrial wastewater is a valuable and meaningful research field. For the first time, a novel Ti/SnO2-Sb anode/air diffusion cathode/UV dual photo-electro catalysis coupling system (T-A-PE) for real antibiotic industrial wastewater treatment was investigated. Non-significant degradation was found in raw wastewater with high TOC = 2.61 × 103 mg·L−1. However, the increasing TOC removal with more dilution times indicated adaptability of T-A-PE system with lower organic matter loading. The highest 95.6% removal of TOC was obtained at 120 min, with 7.06 mA·cm−2 of current density and 200 dilution times. The high mineralization efficiency of T-A-PE system surpassed those of pure photo and electro catalysis combined, suggesting a significant synergistic effect between photo and electro catalysis. Neutral condition and current density = 7.06 mA·cm−2 are prior for pollutants mineralization, while acidic/alkaline conditions and unproper current density may cause faster side reactions. The GC–MS results demonstrated that the number of pollutant category dropped from 26 to 6 after treatment, with the concentrations of remained ones also remarkably decreased. The acute toxicity analysis using a luminescent bacteria method indicated that the treated wastewater by T-A-PE system was biological harmless.

Photocatalytic degradation of typical pharmaceuticals in natural sunlight and in actual water is of great significance. In this study, the oxygen or nitrogen linked heptazine-base polymer (ONLH) was successfully incorporated with TiO2 nanoparticles and formed a TiO2/ONLH nanocomposite which was responded to the natural sunlight. Under natural sunlight, the TiO2/ONLH can effectively degrade ten types of pharmaceuticals. In particular, fluoroquinolone containing N-piperazinyl, and cardiovascular drugs containing long aromatic side chains were easily degraded. The half-life of the best degradation performance of propranolol was less than 5 min. The rate constants of propranolol using the TiO2/ONLH were approximately six- and eight-fold higher than those of pristine TiO2 and ONLH, respectively. Two reactive species (OH and O2-) facilitated the rapid degradation of propranolol, which occurred primarily through the hydroxyl radical addition, ring-opening, and ipso substitution reactions. An acute toxicity test using luminescent bacteria indicated that the toxicity of the propranolol reaction solution gradually decreased with lower total organic carbon (TOC). According to the toxicity evaluation of monomer products, the TiO2/ONLH also reduced the generation of toxic transformation products. The effects of actual water/wastewater have further shown the TiO2/ONLH might be applied for the removal of pharmaceuticals in wastewater.

Bioremediation using microorganisms is a promising technique to remediate soil contaminated with heavy metals. In this study, Sporosarcina pasteurii (S. pasteurii) bioremediation by mixing method was used to remediate soils contaminated with lead (Pb), zinc (Zn) and cadmium (Cd). A significant reduction of heavy metal leaching concentrations was observed in S. pasteurii bio-treated samples. Furthermore, urease hydrolyzing bacteria have additional advantages of accelerating metal precipitation by increasing pH. The soluble-exchangeable Pb, Zn and Cd was reduced by 33.3 % ∼ 85.9 %, 21.4 % ∼ 66.0 %, 13.6 % ∼ 29.9 % respectively after bioremediation. The primary objective of metal stabilization was achieved by reducing the bioavailability through immobilizing the Pb, Zn and Cd in the urease-driven carbonate precipitation. Luminescent bacteria toxicity experiments revealed that the metal toxicity of contaminated soil was reduced after bioremediation using S. pasteurii. When subjected to severe environmental conditions, S. pasteurii bioremediation was superior to chemical precipitation technology in terms of long-term stability.

Natural sunlight is a vital environmental element and plays a significant role in the ecological storage of reclaimed water (RW), but its impacts on RW quality are poorly understood. In this study, sunlight-induced changes in RW with a focus on dissolved organic matter (rDOM) and 52 residual micropollutants were investigated in the field during the summer and winter seasons. The results indicated that sunlight exposure led to the dissipation of chromophoric DOM (CDOM) in the summer (55% loss) and winter (19% loss) after 14 consecutive sunny days. During open storage of RW, CDOM absorption in UVC regions was preferentially removed in the summer, while during the winter there was preferential removal of CDOM in UVA regions. The results also showed higher fluorescent DOM (FDOM) removal in summer than in winter (49% and 28%, respectively). Results in both seasons indicated that humic acid-like compounds were the most photolabile fractions and were preferentially removed under sunlight exposure. Sunlight also induced attenuation of micropollutants in the summer and winter at reductions of 66% and 24% from the initial values, respectively. Significant attenuation (>75%) was only observed for endocrine-disrupting chemicals, pharmaceuticals, and sunscreens in the summer, but they accounted for 76% of the total concentrations. Vibrio fischeri toxicity tests demonstrated that sunlight constantly decreased the luminescent bacteria acute toxicity of RW, which was estimated to be caused mainly by the sunlight-induced changes of FDOM and CDOM, while the detected micropollutants could only explain 0.02%–2% of acute toxicity. These findings have important implications regarding our understanding of the ecological storage of reclaimed water and the contribution of management strategies.

The antipsychotic drug quetiapine (QUT) has been frequently detected in sewage treatment plants. However, information on the fate of QUT in aquatic environments and its behavior during UV treatment is limited. In this study, QUT is shown not to be readily biodegradable in the Closed Bottle Test and the Manometric Respirometry Test according to OECD guidelines. The main biotransformation product (BTP) formed in the tests, a carboxylic acid derivative, was identified by means of high-resolution mass spectrometry. This BTP is presumably a human metabolite and showed higher detection rates than QUT in a river sampling campaign conducted in northern Germany. UV elimination kinetics of QUT at different initial concentrations (226.5, 45.3, 11.3, and 2.3 μmol L −1 ) were faster at lower initial concentrations. All seven phototransformation products (PTPs) could be still identified at initial concentration of 11.3 μmol L −1 . The photolytic mixture generated after 128 min of photolysis of QUT was not better biodegradable than QUT. Initial UV treatment of QUT led to the formation of several additional BTPs. Four of them were identified. The bacterial cytotoxicity and genotoxicity before and after phototransformation of QUT in a modified luminescent bacteria test (LBT) and the umu-test (ISO/FDIS 13829) showed cytotoxic effects in the LBT for QUT. Furthermore, PTPs had similar cytotoxic effects on luminescent bacteria. The umu-test did not reveal any genotoxic activity for QUT or PTPs. In conclusion, the release of QUT into sewage treatment plants and aquatic environments could result in the formation of a main BTP. Additional UV treatment of QUT would lead to the formation of additional BTPs. Moreover, treatment did not result in lower toxicity to tested organisms. In conclusion, UV treatment of QUT should be considered critically as a potential treatment for QUT in aquatic systems.

Explosive-contaminated soil is harmful to people’s health and the local ecosystem. The acute toxicity of its extracting solution was tested by bacterial luminescence assay using three kinds of luminescent bacteria to characterize the toxicity of the soil. An orthogonal test L 16 (45) was designed to optimize the soil extracting conditions. The optimum extracting conditions were obtained when the ultrasonic extraction time, ultrasonic extraction temperature, and the extraction repeat times were 6 h, 40 °C, and three, respectively. Fourier transform infrared spectroscopy (FTIR) results showed that the main components of the contaminated soil’s extracting solution were 2,4-dinitrotoluene-3-sulfonate (2,4-DNT-3-SO3 −); 2,4-dinitrotoluene-5-sulfonate (2,4-DNT-5-SO3 −); and 2,6-dinitrotoluene (2,6-DNT). Compared with Photobacterium phosphoreum and Vibrio fischeri, Vibrio qinghaiensis sp. Nov. is more suitable for assessing the soil extracting solution’s acute toxicity. Soil washing can remove most of the contaminants toxic to luminescent bacterium Vibrio qinghaiensis sp. Nov., suggesting that it may be a potential effective remediation method for explosive-contaminated soil.

The wastewater generated in pharmaceutical process generally contains residual organic solvents (ROSs) which will cause the toxicity and inhibition of the micro-organisms in treating wastewater, thus affecting the treatment effect of wastewater. The aim of this study was to establish a system for the analysis and evaluation of microtoxicity and biodegradability of ROSs in pharmaceutical wastewater. The quantitative structure activity relationship models were used to predict the toxicity and biodegradability; meanwhile, the biological toxicity was tested by the method of dehydrogenase activity (DHA) as well as luminescent bacteria and biodegradability was measured by shaking experiment. The proposed system was applied to predict and evaluate toxicity and biodegradability of toluene, acetone, isopropanol and dichloromethane in pharmaceutical wastewater. The results showed that the actual measured values fitted well with the calculated values. The microtoxicity of toluene was the highest and the degr...

2,4-DCP is a high-toxicity phenol compound, which is difficult to remove, harmful to the health of people and seriously influences the aquatic ecosystems. In this study, the degradation of 2,4-DCP using UV/persulfate (UV/PS) process was investigated for the first time. The results showed pseudo-first-order rate constants of 2,4-DCP photo-degradation by UV/PS was 35.1 × 10−3 min−1. The reaction rate constants increased with pH increasing from 5 to 7 and then decreased at pH 8. Different anions (Cl−, HCO3− and NO3−) in water presented different effects on the photo-degradation reaction. The photo-degradation rates of 2,4-DCP in three actual water conditions (Xidong water works, Xijiu reservoir, Henshan reservoir) were higher than in the ultrapure water. Two possible (hydroxylated and dechlorinated) pathways for the degradation of 2,4-DCP by UV/PS were proposed. The luminescent bacteria inhibition rate greatly decreased with the concentration of 2,4-DCP decreasing in the reaction process.

Vibrio fischeri bioluminescence inhibition has been widely used to test acute toxicities of metals and organics contaminants. However, the differences of metals and organics acute toxicities to V. fischeri have not been compared. Here, four heavy metals (Zn2+, Cu2+, Cd2+, Cr6+) and five organics (phenol, benzoic acid, p-hydroxy benzoic acid, nitro-benzene and benzene) acute toxicities to V. fischeri were investigated. Heavy metals toxicities to V. fischeri were increased along with the reaction time, while the organics toxicities kept the same level in different reaction times. In order to explain the difference, the relative cell death rate of V. fischeri was detected. In metals toxicities tests, the bioluminescence inhibition rate of V. fischeri was found to be significantly higher than the relative cell death rate (P

Psychoactive drug diazepam is one of benzodiazepines widely used in human medicine. It has been found to be relatively resistant to chlorination and photolysis. Here we investigated the transformation mechanism of diazepam in aqueous solution through UV/chlorine and simulated sunlight/chlorine treatments. The results showed that the UV/chlorine and sunlight/chlorine processes significantly increased the degradation of diazepam in water. These observed degradations can be elucidated by in-situ generation of reactive species including hydroxyl radical (HO ), reactive chlorine species (RCS) and ozone (O3) during photolysis of chlorine. In the UV/chlorine treatment, the degradation efficiency of diazepam for HO , chlorine, UV and RCS reaction at 90 min was calculated to be 62.1%, 3.8%, 11.9% and 12.3%, respectively. In the simulated sunlight/chlorine treatment, the calculated degradation of 53.1%, 8.1% and 11.2% was attributed to HO , chlorine and RCS reaction, with negligible loss by O3 reaction and sunlight irradiation. In the UV/chlorine and sunlight/chlorine treatments, a total of 70 transformation products was detected using a high-resolution TripleTOF mass system. Six transformation pathways have been tentatively proposed for the diazepam, which includes hydroxylation, chlorination, hydrolyzation, N-demethylation, loss of phenyl group, benzodiazepine ring rearrangement and contraction. Most of the obtained transformation products were less toxic to aquatic organisms including fish, daphnia and green algae than diazepam itself according to the toxicity prediction tool, and did not cause significant changes in toxicity to luminescent bacteria.

Residual trace organic pollutants (TOPs) and associated biological effects from secondary effluent (SE) are attracting much attention because of their safety concerns. Granular activated carbon (GAC) adsorption, due to its low cost and high efficiency, is widely applied for further wastewater treatment, but its selective removals of TOPs and biological effects are poorly understood. In the present study, the surface physicochemical characteristics of four types of typical GACs were investigated, and their correlation with luminescent bacteria toxicity was discussed. Based on the biological effect control, shell GAC, with a great adsorption capacity and high functional group contents was selected for further study, including for the removal of fluorescent dissolved organic matter (DOM), 21 TOPs, and 3 biological effects. The shell GAC showed a promising property of removing fluorescent DOM and TOPs. The total concentration of 21 detected TOPs, including 12 pesticides and 9 pharmaceuticals, achieved 82% removal when 30 g/L shell GACs was added. Individual chemicals removal by GAC adsorption was not well described by an individual parameter (e.g., logD, molecular size, charge, functional groups), but rather by a variety of physical and chemical interactions among TOPs, DOM, and GAC. The biological effects from SE were mainly caused by TOPs and DOM. Hence, shell GACs also showed high removal efficiencies of luminescent bacteria toxicity, genotoxicity, and photosynthetic inhibition effect. The removal mechanisms of the three biological effects from SE were deeply discussed. Therefore, the GAC treatment is considered to be one of the most suitable options to ensure the ecological safety of discharged wastewater, because it can effectively control DOM, TOPs, and associated biological effects.

Advanced oxidation processes (AOPs) can degrade heavy metal complexes in wastewater to improve the removal efficiency of metals. However, the influences of AOP treatments on toxicity induced by metal complexes are not well understood. This study compared the toxicity induced by EDTA-copper (Cu) after UV/persulfate (PS) and UV/H2O2 treatments on luminescent bacteria and human HepG2 cells. The results showed that EDTA-Cu complexes decreased Cu toxicity in luminescent bacteria but increased the cytotoxicity in HepG2 cells, indicating species-specific toxicity. The UV/PS and UV/H2O2 treatments under most pH values and [oxidant]/[EDTA-Cu] conditions decreased the toxicity of EDTA-Cu in HepG2 cells but increased the toxicity in luminescent bacteria. When the ratio of [oxidant] to [EDTA-Cu] was 10, low toxicity in treated solutions was observed in both UV treatment processes. The alkaline precipitation treatment had a significant influence on toxicity reduction after UV/PS treatment; however, it had minimal influence on the UV/H2O2 treatment system. The Cu and total organic carbon (TOC) removal efficiency cannot completely explain the results of toxicity assays. EDTA-Cu intermediates might play important roles in changing the toxicity of EDTA-Cu after both UV treatments. This study provides insights into evaluating the treatment efficiency of UV/PS and UV/H2O2 on EDTA-Cu decomplexation.

The environmental compatibility of reactive fire-retardant coatings (intumescent paints) was investigated by a combination of leaching and ecotoxicological tests. Three representative fire-retardant coating systems were tested using two leaching procedures: “Horizontal Dynamic Surface Leaching Test” (DSLT) and the “Intermittent Immersion Test” (IIT). All eluate fractions (8 for DSLT and 9 for IIT) were analyzed for pH, conductivity, concentration of total organic carbon and selected anions und cations. Additionally, a GC-MS screening of selected fractions was conducted for identification of organic compounds. Eluate fractions 1 + 2 and fraction 7 of the DSLT were analyzed in four ecotoxicological tests (algae, daphnia, fish egg, luminescent bacteria) and in one genotoxicity test (umu). Concentration of most analytes was rather low or below limit of detection for many eluates. Analytes detected in eluates of all three products are Zn, Ba, SO42− and PO43−. Release patterns do not indicate a general trend: some compounds show maximum release in the first fractions while for others the maximum was observed in later test stages. Ecotoxic effects in eluates were found, which were higher in the eluate fraction 7 (maximum lowest ineffective dilution for luminescent bacteria (LIDL) 256) than in the eluate fraction 1 + 2 (maximum LIDL = 24). The sensitivity of the test systems was very different with highest effects for luminescent bacteria, followed by algae and daphnia and without effects in the fish egg test and umu test. A biotest battery for the comprehensive assessment is therefore advisable.

Chlorination is essential to provide safe drinking water. However, this process leads to the formation of disinfection byproducts (DBPs). In this study, tryptophan (Trp) has been selected as a precursor to conduct the chlorine disinfection. Moreover, the factors that affect the formation of trihalomethanes (THMs) and iodinated trihalomethanes (I-THMs) are investigated. The formation pathway of Trp chlorination is proposed based on the intermediate products identified. According to the experimental results, the formation of THMs and I-THMs during Trp chlorination fitted a new first-order kinetic model. The dosage of chlorine, temperature, pH and the ratio of bromide and iodide had major influence on the formation of THMs and I-THMs during chlorination. In addition, the inhibition of luminescent bacteria Vibrio fischeri in the water sample increased during Trp chlorination.

Ultraviolet (UV) photodegradation is increasingly applied to control volatile organic compounds (VOCs) due to its degradation capabilities for recalcitrant compounds. However, sometimes the UV photodegradation products are also toxic and can affect human health. Here, 10 VOCs at 150~200 ppm in air were treated using a laboratory-scale UV reactor with 185/254 nm irradiation, and the biotoxicity of their off-gas was studied by investigating their off-gas absorption solutions. The CO2 increase and VOC decrease were 39~128 ppm and 0~42 ppm, respectively, indicating that the VOCs and their products were mineralized in off-gas absorption solutions. The total organic carbon (TOC) of the absorption solutions are 4~20 mg∙L&minus, 1. Luminescent bacteria and Daphnia magna were used to detect the acute toxicity, and an umu assay was used to determine the genotoxic potential. Trichloroethylene showed a highest toxicity to luminescent bacteria, while chlorobenzene had the lowest toxicity. Water-soluble UV photodegradation products for styrene are very toxic to Daphnia magna. In the umu assay, the genotoxicities of off-gas absorption solutions of trichloroethylene, methylbenzene, ethyl acetate, butyl alcohol, and styrene were 51.26, 77.80, 86.89, 97.20, and 273.62 mg (4-NQO)&middot, L&minus, 1 respectively. In addition, the analysis of the genotoxicity/TOC and intermediates products indicated that the off-gas absorption solutions of styrene, trichloroethylene, and butyl alcohol contain many highly toxic substances.

In 2013, the “Qingdao oil pipeline explosion” released an estimated 2000 tons of oil into the environment. Sediment samples were collected from ten sites in Jiaozhou Bay and Shilaoren Beach to evaluate the influence of the spilled oil on the benthic environment 3 years after the oil spill accident. The compositions of oil, bacterial diversity and biotoxicity were examined in this study. The results showed that the concentration of total petroleum hydrocarbons (TPHs) peaked near the oil leak point and gradually decreased along the coastline, ranging from 21.5 to 133.2 μg/g. The distribution of polycyclic aromatic hydrocarbons (PAHs) was correlated with TPH, and naphthalenes were dominant in the 20 detected PAHs. The bacterial diversities in seriously polluted and slightly polluted sediments were completely different. As degrading bacteria, Alcanivorax and Lutibacter were the main genera at the oil-polluted sites. The analysis of biotoxicity by the luminescent bacteria method showed great differences among the polluted sites, the control site in Jiaozhou Bay, and the non-polluted site outside of Jiaozhou Bay. The biotoxicity also peaked at the site near the oil leak point. These results indicate that the oil spill that occurred 3 years ago still affects the environment and impacts the bacterial communities in the sediments. Electronic supplementary material The online version of this article (10.1186/s13568-018-0603-6) contains supplementary material, which is available to authorized users.

In this study, peroxydisulfate (PDS) was successfully activated by nanoscale zero-valent iron (nZVI) for the degradation of sulfamethoxazole (SMX, antibiotic frequently detected in the environment) in agricultural soils. The results indicated that the degradation of SMX was affected by the nZVI dose, the ratio of SMX/PDS, the ratio of soil/water and reaction temperature, and in cinnamon soils 87.6% of SMX degradation can be achieved within 4 h at 30 °C when the initial nZVI dose was 0.03 g g−1 soil, the molar ratio of SMX/PDS = 1/75 and the soil/water = 1/1. The results of radical scavenger experiments and electron spin resonance (ESR) tests showed that hydroxyl radical ( OH) was the dominant reactive species in this system. The ecotoxicity tests of the soil by germination test, luminescent bacteria experiment and enzyme activity test indicated that the ecotoxicity of soil after treatment was obviously lower than the contaminated soil. In addition, there was almost no effect on plant growth when compared with original soil. Furthermore, this system exhibited a great degradation capacity for SMX in different types of agricultural soils, and the degradation efficiencies of SMX in other four soils were 90.6% (yellow brown earths), 80.8% (brown earths), 86.5% (black soils) and 96.1% (red earths), respectively. This work provides an optional method for agricultural soil pollution control.

Biotic ligand model (BLM) was extended to predict the toxicity of inorganic arsenate (iAs(V)) to the luminescent bacteria, Aliivibrio fischeri. As the pH increased from 5 to 9, the HAsO42- form predominated more than the H2AsO4- form did, and the EC50[As]T (50% effective iAs(V) concentration) decreased drastically from 3554 ± 393 to 39 ± 6 μM; thus, the HAsO42- form was more toxic to A. fischeri than H2AsO4-. As the HPO42- activity increased from 0 to 0.44 mM, the EC50{HAsO42-} values (50% effective HAsO42- activity) increased from 31 ± 6 to 859 ± 128 μM, indicating that the toxicity of iAs(V) decreased, owing to the competition caused by the structural similarity between iAs(V) and phosphate ions. However, activities of Ca2+, Mg2+, K+, SO42-, NO3-, and HCO3- did not significantly affect the EC50{HAsO42-} values. The BLM was reconstructed to take into account the effects of pH and phosphate, and the conditional binding constants for H2PO4-, HPO42-, H2AsO4-, and HAsO42- to the active binding sites of A. fischeri were obtained; 3.424 for logKXH2PO4, 4.588 for logKXHPO4, 3.067 for logKXH2AsO4, and 4.802 for logKXHAsO4. The fraction of active binding sites occupied by iAs(V) to induce 50% toxicity (fmix50%) was found to be 0.616.