Decabromodiphenyl ether (DBDE), which has been identified as an endocrine disrupting compound, is used as brominated flame retardant, and this can result in serious bioaccumulation within ecological systems. The objective of this study was to explore DBDE bioremediation (25 mg/kg) using laboratory scale soil slurry microcosms. It was found that effective biodegradation of DBDE occurred in all microcosms. Various biometabolites were identified, namely polybrominated diphenyl ethers congeners and hydroxylated brominated diphenyl ether. Reductive debrominated products such as tri-BDE to hepta-BDE congeners were also detected, and their total concentrations ranged from 77.83 to 91.07 ng/g. The mechanism of DBDE biodegradation in soil slurry microcosms is proposed to consist of a series of biological reactions involving hydroxylation and debromination. Catechol 2,3-oxygenase genes, which are able to bring about meta-cleavage at specific unbrominated locations in carbon backbones, were identified as present during the DBDE biodegradation. No obvious effect on the ecological functional potential based on community-level physiological profiling was observed during DBDE biodegradation, and one major facultative Pseudomonas sp. (99 % similarity) was identified in the various soil slurry microcosms. These findings provide an important basis that should help environmental engineers to design future DBDE bioremediation systems that use a practical microcosm system. A bacterial-mixed culture can be selected as part of the bioaugmentation process for in situ DBDE bioremediation. A soil/water microcosm system can be successfully applied to carry out ex situ DBDE bioremediation.

The bioaccessibilites of heavy metals in vegetables grown around a waste-incinerator site were estimated using the physiologically based extraction test (PBET) method, to assess potential health risk to the local consumers. The average gastric and intestinal bioaccessibilities of Cd, Cr, Cu, Ni, and Pb in vegetables varied within 3.2–9.4 and 0.8–5.3 %, 1.4–2.3 and 1.1–1.9 %, 25–46 and 13–26 %, 6.6–30 and 2.6–5.3 %, 11–29 and 7.1–23 %, respectively. Strong negative correlations were found between electrochemical potential (ΔE ₀) and bioaccessibility for leaf mustard samples (r ² = 0.857) and leaf lettuce samples (r ² = 0.696). In addition, softness index (σp) and electrochemical potential (ΔE ₀) exhibited a moderate but not significant relationship with bioaccessibilities on the basis of the multiple regression analysis (0.05 < p < 0.1). The total bioaccessible target hazard quotient (TBTHQ) of the five heavy metals was 2.5, with Pb being the major risk contributor. According to the TBTHQs of each group of vegetables, local consumers are experiencing adverse health effects by consuming most of the vegetables around waste-incinerator site.

The bioconcentration potential of fluoxetine (FLX) and its biological effects were investigated in juvenile Pacific oyster exposed for 28 days to environmentally relevant concentrations of FLX (1 ng L⁻¹, 100 ng L⁻¹ and up to 10 μg L⁻¹). FLX bioaccumulated in oyster flesh resulting in 28-day bioconcentration factors greater than 2,000 and 10,000 by referring to wet and dry weights, respectively. Nevertheless, FLX did not induce oyster mortality, delayed gametogenesis, or lead to adverse histopathological alterations. At the two highest concentrations, despite non-optimal trophic conditions, FLX stimulated shell growth but only in a transient manner, suggesting a role of serotonin in the regulation of feeding and metabolism in bivalves. Those high concentrations seemed to drive bell-shaped responses of catalase and glutathione S-transferase activities throughout the exposure period, which may indicate the activation of antioxidant enzyme synthesis and then an enhanced catabolic rate or direct inhibition of those enzymes. However, no clear oxidative stress was detected because no strong differences in thiobarbituric acid-reactive substance (TBARS) content (i.e. lipid peroxidation) were observed between oyster groups, suggesting that cellular defence mechanisms were effective. These results demonstrate the importance of considering additional biomarkers of oxidative stress to obtain a comprehensive overview of the FLX-induced changes in marine bivalves exposed under realistic conditions. Considering the battery of biomarkers used, FLX appears to induce little or no effects on oyster physiology even at a concentration of 10 μg L⁻¹. These results do not confirm the lowest observed effect concentration (LOEC) values reported by some authors in other mollusc species.

A soil column leaching experiment was conducted to eliminate heavy metals from reclaimed tidal flat soil. Flue gas desulfurization (FGD) gypsum was used for leaching. The highest removal rates of Cd and Pb in the upper soil layers (0–30 cm) were 52.7 and 30.5 %, respectively. Most of the exchangeable and carbonate-bound Cd and Pb were removed. The optimum FGD gypsum application rate was 7.05 kg·m⁻², and the optimum leaching water amount for the application was 217.74 L·m⁻². The application of FGD gypsum (two times) and the extension of the leaching interval time to 20 days increased the heavy metal removal rate in the upper soil layers. The heavy metals desorbed from the upper soil layers were re-adsorbed and fixed in the 30–70 cm soil layers.

Silver nanoparticles (AgNP) are one of the most marketable nanomaterials worldwide. Their increasing production and their market insertion will deliver AgNP to the environment, exacerbating their human and environmental impacts. This review discusses the main techniques to synthesize AgNP, their properties, applications, and the cutting-edge knowledge on the effects of AgNP on human and environmental health. Through an identification of papers reporting AgNP until the beginning of 2016 in “ISI Web of Science,” and running different combinations of keywords or search strings, we identified six toxicological factors with a clear hazard potential to workers and consumers. A grading system is proposed to rank and evaluate toxicological properties of AgNP, which can be useful in supplying assistance on the classification of the priorities and concerns in the regulatory and standardization policies of the occupational health and safety issues on nanomaterials.

This paper presents the study of the occurrence of ten endocrine-disrupting compounds in twenty wastewater samples, collected from different sampling points throughout a wastewater treatment plant process. This work was assessed using ultra-performance liquid chromatography with electrospray ionization-tandem mass spectrometry that provides simultaneous quantification and confirmation of the presence of these emerging compounds. All samples were previously cleaned with vacuum filtration and extracted by solid-phase extraction. The compounds studied in this work are 17β-estradiol, ethinylestradiol, estriol, estrone, progesterone, mestranol and diethylstilbestrol, 4-n-nonylphenol, 4-tert-octylphenol and bisphenol A. The analytical limits were calculated for each compound and were used to identify and these target compounds in a wastewater treatment plant. The main conclusions obtained during this study emphasized that wastewater is an important contamination source of these compounds, the most common being bisphenol A and nonylphenol and wastewater treatment plants are not structured to remove endocrine-disrupting compounds. However some removal efficiencies were achieved for estriol (around 98 %) and bisphenol A (around 67 %) along treatment process, indicating that with some preventive approaches it is possible to minimize this problem.

Biochar can potentially reduce fumigant emissions in agriculture. Dimethyl disulfide (DMDS) is an effective soil fumigant for controlling soil-borne pests. However, it is important to reduce DMDS emissions because the compound has an unpleasant and easily perceived sulfur odor. This study therefore aimed to determine the effects of two types of biochar amendments on DMDS bioactivity and emission, using bioassay methods and soil columns. The efficacy of DMDS for controlling root-knot nematode and Fusarium spp. was not reduced when the biochar used in this study was applied at a rate less than 2 and 0.5 % (on a weight basis), respectively. The biochar with high specific surface area (SSA 113 m⁻² g⁻¹) reduced the efficacy of DMDS against soil-borne pests more than the low SSA biochar (14 m⁻² g⁻¹). Increased doses of DMDS were able to offset decreases in the efficacy of DMDS in soils amended with biochars, except for high SSA biochar applied at a rate of 2 %. Biochar amendments applied to the soil surface at shallow depth can significantly reduce DMDS emission to the atmosphere. The results of this study will support decision-making about the practical use of biochar to reduce DMDS emissions.

Mn-Fe/TiO₂ catalysts synthesized by sol-gel and co-precipitation methods were used for the selective catalytic reduction (SCR) of NO with NH₃. The catalysts were characterized by N₂ physisorption, XRD, NH₃/NOₓ-TPD, and H₂-TPR. The catalytic activities for SCR and NH₃/NO oxidation were investigated in the absence and presence of water. In this study, Mn-Fe/TiO₂(S) catalyst exhibited better catalytic activity at low temperature below 175 °C in the absence of H₂O. However, more by-product of N₂O was observed in this case in contrast with Mn-Fe/TiO₂(C). The similar phenomenon was observed during the process of NH₃ catalytic oxidation. The excellent redox capability and abundant active adsorbed species on the catalyst surface accounted for higher NOₓ conversion and more N₂O formation for Mn-Fe/TiO₂(S). It was found that water vapor hindered the activation of NH₃ and adsorption-oxidation of NO, and thus, impeded catalytic activity of Mn-Fe/TiO₂ during standard SCR process at low temperature, even though it reduced the formation of N₂O. The inhibition for over dehydrogenation of amide adsorbed species and the deceleration for decomposition of ammonium nitrate species might be two reasons accounting for the decrease of N₂O concentration in the presence of H₂O. The different catalysts exhibited the different poisoning resistance to SO₂ and the SO₂ resistance of manganese-based catalyst at low temperature still needed the further improvement.

The ultraviolet light (UV-A) range of 320–400 nm is widely used as light trap for insect pests. Present investigation was aimed to determine the effect of UV light-A radiation on development, adult longevity, reproduction, and development of F₁ generation of Mythimna separata. Our results revealed that the mortality of the second instar larvae was higher than the third and fourth instar larvae after UV-A radiation. As the time of UV-A irradiation for pupae prolonged, the rate of adult emergence reduced. Along with the extension of radiation time decreased the longevity of adult females and males. However, the radiation exposure of 1 and 4 h/day increased fecundity of female adults, and a significant difference was observed in a 1 h/day group. The oviposition rates of female adults in all the treatments were significantly higher than the control. In addition, UV-A radiation treatments resulted in declined cumulative survival of F₁ immature stages (eggs, larvae, and pupae). After exposure time of 4 and 7 h/day, the developmental periods of F₁ larvae increased significantly, but no significant effects on F₁ pupal period were recorded.

The objective of the study is to improve understanding of natural phosphorus removal processes to limit the need for chemical addition in an existing facultative wastewater stabilization pond in Manitoba, Canada. Surface samples were collected from lagoon cells and analyzed. The windward and leeward sides of the ponds were sampled and the results were averaged. Phosphorus appears to be removed by assimilation into biomass; and precipitation at alkaline pH. When the nitrogen to phosphorus (N/P) ratio and ideal theoretical N/P ratio for cellular growth are compared, there appears to be nitrogen-limiting conditions in the secondary cells of the stabilization system. There is evidence ammonia removal by free ammonia volatilizing to the atmosphere may be contributing to nitrogen-limiting conditions in the secondary lagoon cells. Additional nitrogen may need to be supplied to remove more phosphorus by assimilation into biomass.