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Environmental Science. Processes & Impacts

Andrew C Maizel, Christina K Remucal
Excited triplet states of dissolved organic matter ((3)DOM) are quantified directly with the species-specific probes trans,trans-hexadienoic acid (HDA) and 2,4,6-trimethylphenol (TMP), and indirectly with the singlet oxygen ((1)O2) probe furfuryl alcohol (FFA). Although previous work suggests that these probe compounds may be sensitive to solution conditions, including dissolved organic carbon concentration ([DOC]) and pH, and may quantify different (3)DOM subpopulations, the probes have not been systematically compared...
July 11, 2017: Environmental Science. Processes & Impacts
Antoine Gosset, Claude Durrieu, Frédéric Orias, Rémy Bayard, Yves Perrodin
Urbanization has led to considerable pressure on urban/suburban aquatic ecosystems. Urban Wet Weather Discharges (UWWD) during rainfall events are a major source of pollutants leached onto and into urban surfaces and sewers, which in turn affect aquatic ecosystems. We assessed the ecotoxicity of the different compounds identified in UWWD and identified the hazard represented by each of them. To this end, hazard quotient (HQ) values were calculated for each compound detected in UWWD based on their predicted no effect concentration (PNEC) values and their maximum measured effluent concentrations (MECmax) found in the dissolved part of UWWD...
July 10, 2017: Environmental Science. Processes & Impacts
Megan B McConville, Stephen P Mezyk, Christina K Remucal
3-Trifluromethyl-4-nitrophenol (TFM) and 2',5-dichloro-4'-nitrosalicylanilide (niclosamide) are lampricides used in tributaries of the Great Lakes to kill the invasive parasitic sea lamprey (Petromyzon marinus). Although the lampricides have been applied since the late 1950s, their photochemical behavior in natural environments is still not well understood. This study examines the indirect photodegradation of these two compounds and the resulting yields of organic and inorganic photoproducts in water samples collected from five tributaries of Lake Michigan...
July 4, 2017: Environmental Science. Processes & Impacts
Swatantra Pratap Singh, Saumyen Guha, Purnendu Bose
Abiotic and bacterial degradation is presented for the two isomers α- and β- of the organochlorine pesticide endosulfan, denoted as ES-1 and ES-2, respectively. Biodegradation studies were conducted with two indigenous species Pseudomonas putida (P. putida) and Rhodococcus sp. Both ES isomers rapidly hydrolyzed in water at pH ≥ 7 but the hydrolysis was inhibited in the presence of biomass. The pesticide partitioned onto the biomass making it unavailable for abiotic hydrolytic reaction. Spontaneous temperature dependent abiotic conversion of ES-2 to ES-1 was reported in the presence of dual air-water phases but was not observed in the abiotic aqueous phase...
June 28, 2017: Environmental Science. Processes & Impacts
A Guzzonato, F Puype, S J Harrad
Brominated flame retardants (BFRs) have been used intentionally in a wide range of plastics, but are now found in an even wider range of such materials (including children's toys and food contact articles) as a result of recycling practices that mix BFR-containing waste plastics with "virgin" materials. In this study Br was quantified in toy and food contact samples on the assumption that its concentration can be used as a metric for BFR contamination. Subsequently, compound specific determination of BFRs was performed to evaluate the validity of the aforementioned assumption, crucial to render rapid, inexpensive, in situ Br determination in non-laboratory environments (such as waste handling facilities) a viable option for sorting wastes according to their BFR content...
June 21, 2017: Environmental Science. Processes & Impacts
H P H Arp, T N Brown, U Berger, S E Hale
The contaminants that have the greatest chances of appearing in drinking water are those that are mobile enough in the aquatic environment to enter drinking water sources and persistent enough to survive treatment processes. Herein a screening procedure to rank neutral, ionizable and ionic organic compounds for being persistent and mobile organic compounds (PMOCs) is presented and applied to the list of industrial substances registered under the EU REACH legislation as of December 2014. This comprised 5155 identifiable, unique organic structures...
June 19, 2017: Environmental Science. Processes & Impacts
Thomas L King, Brian Robinson, Fangda Cui, Michel Boufadel, Kenneth Lee, Jason A C Clyburne
Canada's production, transport, and sale of diluted bitumen (dilbit) products are expected to increase by a million barrels per day over the next decade. The anticipated growth in oil production and transport increases the risk of oil spills in aquatic areas and places greater demands on oil spill capabilities to respond to spills, which have raised stakeholder concerns. Current oil spill models only predict the transport of bitumen blends that are used in contingency plans and oil spill response strategies, rather than changes in the oil's physical properties that are relevant to spill response...
June 14, 2017: Environmental Science. Processes & Impacts
A C Mehinto, D R VanDervort, W Lao, G He, M S Denison, S M Vliet, D C Volz, R D Mazor, K A Maruya
The impact of unmonitored contaminants, also known as contaminants of emerging concern (CECs), on freshwater streams remains largely uncharacterized. Water samples from 31 streams representing urban, agricultural and undeveloped (i.e., open space) land use in Southern California (USA) were analyzed for in vitro and in vivo bioactivity. The extent and magnitude of bioactivity screened using endocrine-responsive cell bioassays and a fish embryo screening assay were low. In contrast, a wider gradient of responses for the aryl hydrocarbon receptor (AhR) assay was observed, which was negatively correlated with a measure of benthic community structure...
June 14, 2017: Environmental Science. Processes & Impacts
Andreas Baumer, Kai Bittermann, Nils Klüver, Beate I Escher
In numerous studies on the toxicity of ionisable organic chemicals, it has been shown that the toxicity was typically higher, when larger fractions of the neutral species were present. This observation was explained in some cases by slower uptake of charged species. In other cases it was suggested that the neutral species has intrinsically higher toxicity than the charged species or is alone responsible for the toxicity. However, even permanently charged and organic chemicals with multiple acid and base functional groups and zwitterions are toxic...
June 2, 2017: Environmental Science. Processes & Impacts
Montse Mari, Joaquim Rovira, Francisco Sánchez-Soberón, Martí Nadal, Marta Schuhmacher, José L Domingo
This study aimed at evaluating the potential impact of a cement plant after 4 years of the employment of alternative fuel. In June 2015, concentrations of PCDD/Fs and metals were determined in soils, vegetation and air in order to measure potential changes with respect to previous surveys before (July 2011) and after (June 2013) the employment of alternative fuel. Risks to human health were also assessed. In soils, metal levels were similar to those observed in June 2013 (p > 0.05). In comparison with July 2011, the increment was only statistically significant for As and Cd (p < 0...
May 31, 2017: Environmental Science. Processes & Impacts
Megan B McConville, Natan M Cohen, Shawn M Nowicki, Stephen R Lantz, Jase L Hixson, Adam S Ward, Christina K Remucal
The lampricides 3-trifluoromethyl-4-nitrophenol (TFM) and 2',5-dichloro-4'-nitrosalicylanilide (niclosamide) are added to Great Lakes tributaries to target the sea lamprey, an invasive parasitic fish. This study examines the photochemical behavior of the lampricides in Carpenter Creek, Sullivan Creek, and the Manistique River. The observed loss of TFM in Carpenter and Sullivan Creeks (i.e., 34 and 19%) was similar to the loss of bromide in parallel time of passage studies (i.e., 30 and 29%), demonstrating that TFM photodegradation was minimal in both tributaries during the lampricide application...
May 31, 2017: Environmental Science. Processes & Impacts
Y Yao, G H Huang, C J An, G H Cheng, J Wei
Many regions in Canada are facing increasing environmental threats posed by oil and gas exploitation and transportation. These contaminated lands are inevitably subjected to seasonal and diurnal freeze-thawing cycles (FTCs). However, knowledge about the effect of FTCs on the behaviours of hydrophobic contaminants during the aging process of soil is limited. This study investigated the desorption characteristics of phenanthrene in aging soils in the presence of the biosurfactant rhamnolipid under diurnal and seasonal FTC treatments...
June 21, 2017: Environmental Science. Processes & Impacts
Guisheng Song, Yijie Li, Suzheng Hu, Guiju Li, Ruihua Zhao, Xin Sun, Huixiang Xie
The kinetics and temperature-, pH- and salinity-dependences of photobleaching of chromophoric dissolved organic matter (CDOM) in the Yangtze River estuary (YRE) were evaluated using laboratory solar-simulated irradiation and compared to those of Suwannee River humic substances (SRHSs). Nearly all CDOM in water at the head of the estuary (headwater herein) was photobleachable in both summer and winter, while significant fractions of CDOM (13-29%) were resistant to photobleaching in saltier waters. The photobleaching rate constant in the headwater was 25% higher in summer than that in winter...
June 21, 2017: Environmental Science. Processes & Impacts
Hannah V Stein, Courtney J Berg, Jessica N Maung, Lauren E O'Connor, Alexandra E Pagano, Laura A MacManus-Spencer, Margot G Paulick
Organic ultraviolet filter chemicals (UVFCs) are the active ingredients used in many sunscreens to protect the skin from UV light; these chemicals have been detected in numerous aquatic environments leading to concerns about how they might affect aquatic organisms and humans. One commonly used organic UVFC is octyl methoxycinnamate (OMC), better known by its commercial name, octinoxate. Upon exposure to UV light, OMC degrades rapidly, forming numerous photoproducts, some of which have been previously identified...
June 21, 2017: Environmental Science. Processes & Impacts
Cathrine Brecke Gundersen, Gijs D Breedveld, Lena Foseid, Rolf D Vogt
Nitramines are potentially carcinogens that form from the amines used in post-combustion CO2 capture (PCCC). The soil sorption characteristics of monoethanol (MEA)- and dimethyl (DMA)-nitramines have been assessed using a batch experimental setup, and defined indirectly by measuring loss of nitramine (LC-MS/MS) from the aqueous phase (0.01 M CaCl2 and 0.1% NaN3) after equilibrium had been established with the soil (24 h). Nitramine soil sorption was found to be strongly dependent on the content of organic matter in the soil (r(2) = 0...
June 21, 2017: Environmental Science. Processes & Impacts
Tianyuan Li, Qing Chang, Xuyin Yuan, Jizhou Li, Godwin A Ayoko, Ray L Frost, Hongyan Chen, Xinjian Zhang, Yinxian Song, Wenzhi Song
Consumption of crops grown in cadmium-contaminated soils is an important Cd exposure route to humans. The present study utilizes statistical analysis and in vitro digestion experiments to uncover the transfer processes of Cd from soils to the human body through rice consumption. Here, a model was created to predict the levels of bioaccessible Cd in rice grains using phytoavailable Cd quantities in the soil. During the in vitro digestion, a relatively constant ratio between the total and bioaccessible Cd in rice was observed...
June 21, 2017: Environmental Science. Processes & Impacts
Fengwen Wang, Tian Lin, Yuanyuan Li, Zhigang Guo, Neil L Rose
Nine paired samples of atmospheric particulate matter with an aerodynamic diameter less than or equal to 2.5 μm (PM2.5) were collected concurrently from an urban site in Shanghai, China and a background site in Huaniao Island (HNI) in the coastal East China Sea (ECS) between July 21 and 29, 2011. The samples were analyzed for 16 United States Environmental Protection Agency (USEPA) priority polycyclic aromatic hydrocarbons (PAHs), n-alkanes (20 species, C14-C33), hopanes (10 species, C29-C32), and steranes (12 species, C27-C29)...
June 21, 2017: Environmental Science. Processes & Impacts
Rixiang Huang, Peng Yi, Yuanzhi Tang
Quartz crystal microbalances (QCMs) provide a new analytical opportunity and prospect to characterize many environmental processes at solid/liquid interfaces, thanks to their almost real-time measurement of physicochemical changes on their quartz sensor. This work reviews the applications of QCMs in probing the interactions of organic molecules, nanomaterials (NMs) and microbes with solid surfaces. These interfacial interactions are relevant to critical environmental processes such as biofilm formation, fate and transport of NMs, fouling in engineering systems and antifouling practices...
June 21, 2017: Environmental Science. Processes & Impacts
Michael A Stravs, Francesco Pomati, Juliane Hollender
Phytoplankton constitute an important component of surface water ecosystems; however little is known about their contribution to biotransformation of organic micropollutants. To elucidate biotransformation processes, batch experiments with two cyanobacterial species (Microcystis aeruginosa and Synechococcus sp.) and one green algal species (Chlamydomonas reinhardtii) were conducted. Twenty-four micropollutants were studied, including 15 fungicides and 9 pharmaceuticals. Online solid phase extraction (SPE) coupled with liquid chromatography (LC)-high resolution tandem mass spectrometry (HRMS/MS) was used together with suspect and nontarget screening to identify transformation products (TPs)...
June 21, 2017: Environmental Science. Processes & Impacts
Reto S Wijker, Josef Zeyer, Thomas B Hofstetter
Quantifying the extent of biodegradation of nitroaromatic compounds (NACs) in contaminated soils and sediments is challenging because of competing oxidative and reductive reaction pathways. We have previously shown that the stable isotope fractionation of NACs reveals the routes of degradation even if it is simultaneously caused by different bacteria. However, it is unclear whether compound-specific isotope analysis (CSIA) can be applied in situations where multiple pollutants are biodegraded by only one microorganism under multi-substrate conditions...
May 24, 2017: Environmental Science. Processes & Impacts
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