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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. [ABSTRACT FROM AUTHOR]

Tungsten(VI) oxide, WO3, was studied and used as a heterogeneous catalyst for the liquid-phase oxidative abatement and solid-phase decontamination of simulants of chemical warfare agents, CWAs. The catalytic performance of WO3was compared to the one of a soluble W-containing model catalyst, W(IV)-heptaisobutyl polyhedral oligomeric silsesquioxane, W-POSS. In liquid-phase abatement tests, WO3promoted a complete degradation of the toxic agent simulant within 24 h, in the presence of aqueous hydrogen peroxide, at room temperature. In solid-phase decontamination tests, when WO3was mixed with sodium perborate as a solid oxidant, it was also tested in the decontamination of a cotton textile support from organosulfide and organophosphonate agents (simulants of blistering and nerve CWAs, respectively), showing promising performances comparable to, or sometimes better than, a nanostructured TiO2catalyst, taken as a reference material. The environmental impact of the WO3catalyst was assessed on bioluminescentPhotobacterium leiognathiSh1 bacteria, over which no acute nor chronic detrimental effects were recorded. Then, when in contact with a vegetable species such asPhaseolus vulgarisL. (common bean), WO3did not cause damage to the photosynthetic apparatus of the plant, whereas a clear inhibition of the seed germination was evidenced. [ABSTRACT FROM PUBLISHER]

The environmental impact of two biocide-free antifouling paints, fluoropolymer and silicone types, painted on a test cylinder was assessed using a battery of ecotoxicity test and chemical analyses for organic micro-pollutants such as perfluoroalkyl substances (PFAS). A biocide paint containing zinc pyrithione (ZnPT2) and cuprous oxide was assessed as a positive control. A standardized laboratory rotating-cylinder method using each test cylinder with artificial seawater was performed for 45 days. After 1 h rotation, the leaked seawater was subjected for bioassay and chemical analyses twice weekly. The seawater extracts from the biocide paint showed adverse effects on bacteria, algae, and crustaceans, but those from the biocide-free paints did not. The leakage seawater from biocide-free paints, after 7-day continuous rotation, contained the same concentration levels of PFAS as blank seawater used to conduct the tests. Thus, no significant toxicities of the biocide-free paints were found under the conditions of this study. Simultaneous analysis of ZnPT2 and copper pyrithione (CuPT2) was developed using an HPLC with a polymeric resin column, showing that ZnPT2 was converted to CuPT2 by trans-chelation in the leakage seawater from the positive control paint. The experimental results using a laboratory rotating-cylinder method demonstrated that biocide-free paints did not markedly affect three species tested and no PFAS was detected. In contrast, biocide paint was significantly toxic to test species and toxicity of the extract on bacteria was partly responsible for CuPT2 produced in leakage seawater. Thus, a laboratory rotating-cylinder method may be applied for ecotoxicological assessment of antifouling paints. [ABSTRACT FROM AUTHOR]

The advantages of combined approaches for the evaluation of drinking-water quality, such as effect-directed analysis (EDA) consisting of biological and chemical analytical methods are illustrated in this work by comparing a classical and EDA approach applied to samples from China and Germany. The China samples contain polycyclic aromatic hydrocarbons, alkylanilines, chloroanilines, chloronitrobenzenes, chlorobenzothiazoles, chloroalkylphosphates, as well as pesticides ((4-chloro-2-methylphenoxy)ethanoic acid, metolachlor, atrazine, and the insect repellent N,N-diethyl-3-toluamide) in concentrations between 1 and 1000 µg L-1. The toxicity profiles of two River Elbe samples and one sewage-treatment-plant sample, as determined by the luminescent bacteria test, selectively reflect the contamination background: the first profile only possesses two out of eight fractions well above the significance level of 10% inhibition, in the second profile, all but one fraction lie well above this level, exhibiting also a much higher total toxicity in each fraction as compared with the latter sample. In the third example, all fractions are far above the significance level and show a much higher total toxicity, but also the profile shifts towards less polar fractions. [ABSTRACT FROM AUTHOR]

Five municipal sewers with small flow rates (Manarola, Riomaggiore, Portovenere, Tellaro, Bocca di Magra) were studied using the Microtox ® test and a bacterial luminescence bioassay in order to evaluate the water quality in these areas of the eastern Ligurian coast. The work was performed including chemical analysis, microbiological and ecotoxicological assays. Analyses were carried out on both the effluents and the water body close to the pipe discharge. None of the measured chemical parameters exceeded the permitted limits, both in the effluents and in the seawater samples, even if some slightly critical situations were highlighted by the Microtox ® test on the effluents. On the other hand, the Microtox ® appeared to be less effective than another ecotoxicological assay based on the luminescent fraction of epibacteria for the evaluation of seawater quality. The good water quality of the considered areas was assessed although a slightly worse condition was encountered in Bocca di Magra. [ABSTRACT FROM AUTHOR]

Hydrophobic organic pollutants in water from the Huaihe River were extracted by solid phase extraction and sequestered by semipermeable membrane device (SPMD), and those in sediments were extracted by organic solvent. Combined with chemical analysis, Lumistox test and ethoxyresorfin O-deethylase (EROD) assay were carried out for assessing the acute toxicities and the Ah-receptor-related toxic effects of the trace hydrophobic organic pollutants in this aquatic environment. The acute toxicants in water and sediment of the Huaihe River included substituted benzenes and pesticides, mainly 2,4,6-trichlorophenol, atrazine, hexachlorobenzene, and nitrobenzenes as well as persistent EROD inducers or Ah-agonists, including PAHs and PCBs, were determined. The highest acute toxicant concentration occurred at the center of the river (H3), while highest chronic toxicants occurred at upstream (H1). At downstream (H4), the EROD inducers in sediment depicted more persistency. The results also showed that the sampling procedures for waters have significant influences on the results of bioassays. Bioassay for acute toxicants in water using SPE was unable to obtain important information. However, bioassays for sediment extracts and SPMD concentrates showed similar pattern of toxic variation among different locations. [ABSTRACT FROM AUTHOR]