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Environmental Science. Processes & Impacts

Xue-Yuan Bai, Shao-You Lu, Lei Xie, Bo Zhang, Shi-Ming Song, Yuan He, Ji-Ping Ouyang, Tao Zhang
Organophosphorus flame retardants (OPs) are of wide concern due to their presence in human urine and their considerable endocrine disruption and neuro-development toxicity. It has been confirmed that electronic waste (e-waste) dismantling activities have contributed to human exposure to OPs. However, assessments of OP exposure and the health risks for pregnant women and fetuses living in areas associated with e-waste dismantling have been impeded by a lack of data. In this study, six OP metabolites (mOPs) were measured in paired maternal urine and amniotic fluid samples collected from an e-waste dismantling area in Guangdong Province, China...
November 14, 2018: Environmental Science. Processes & Impacts
Lara Schultes, Robin Vestergren, Kristina Volkova, Emelie Westberg, Therese Jacobson, Jonathan P Benskin
Per- and polyfluoroalkyl substances (PFASs) are a diverse class of >4700 chemicals used in commercial products and industrial processes. Concerns surrounding PFASs are principally due to their widespread occurrence in humans and the environment and links to adverse health effects. One of the lesser known uses for PFASs is in cosmetic products (CPs) which come into contact with the skin (e.g. hair products, powders, sunblocks, etc.). In the present work, thirty-one CPs from five product categories (cream, foundation, pencil, powder and shaving foam) were analyzed for 39 PFASs by liquid chromatography-tandem mass spectrometry, as well as extractable organic fluorine (EOF) and total fluorine (TF) by combustion ion chromatography (CIC)...
November 14, 2018: Environmental Science. Processes & Impacts
Michael J Milazzo, Julia M Gohlke, Daniel L Gallagher, Anna A Scott, Benjamin F Zaitchik, Linsey C Marr
Benzene, toluene, ethylbenzene, and xylenes (BTEX) are hazardous air pollutants commonly found in outdoor air. Several studies have explored the potential of vegetation to mitigate BTEX in outdoor air, but they are limited to a northern temperate climate and their results lack consensus. To investigate this subject in a subtropical climate, we deployed passive air samplers for two weeks in parks and outside nearby residences at four locations: three in an urban area and one in a rural area in Alabama, USA. All BTEX concentrations were below health-based guidelines and were comparable to those found in several other studies in populated settings...
November 14, 2018: Environmental Science. Processes & Impacts
Faten Salim, Tadeusz Górecki, Marios Ioannidis
As the applications of passive sampling in environmental analysis are increasing, it is crucial to ensure that the methods applied in the measurement of pollutant concentrations provide sufficient accuracy in compliance with existing regulations. Additionally, as with any sampling method in an analytical process, sample integrity is essential for accurate determination of contaminants and their concentrations. In a recent study, a mathematical model was developed to describe the sampling process in permeation passive samplers...
November 9, 2018: Environmental Science. Processes & Impacts
Laura T Rea, Yi Xu, Nathan E Boland
Trace metal ion speciation in natural waters is often under kinetic control due to slow exchange reactions involving multidentate ligands (both natural and anthropogenic) and constituent ions (e.g. calcium). Incomplete understanding of the kinetic behavior (rates, rate laws, and mechanisms) of multidentate ligand exchange reactions hinders prediction of metal ion bioavailability and mobility in these systems. Here, we aim to improve understanding (1) by examining the mechanism by which calcium suppresses ligand exchange rates and (2) by developing conceptual tools for predicting the kinetic behavior in environmental systems...
November 9, 2018: Environmental Science. Processes & Impacts
Jamie Schenk, Doug D Carlton, Jonathan Smuts, Jack Cochran, Lindsey Shear, Ty Hanna, Danny Durham, Cal Cooper, Kevin A Schug
The ability of different methods to analyze formaldehyde and other leachates from proppants was investigated under lab-simulated downhole conditions. These methods include high performance liquid chromatography (HPLC), headspace gas chromatography-vacuum ultraviolet spectroscopy (HS-GC-VUV), and headspace gas chromatography-mass spectrometry (HS-GC-MS). Two different types of resin-coated proppants, phenol-formaldehyde- and polyurethane-based, were examined. Each proppant was tested at different time intervals (1, 4, 15, 20, or 25 hours) to determine the timeframe for chemical dissolution...
November 7, 2018: Environmental Science. Processes & Impacts
Alexander Leven, Dimitri Vlassopoulos, Masakazu Kanematsu, Jessica Goin, Peggy A O'Day
Addition of Mn(iv)-oxide phases pyrolusite or birnessite was investigated as a remedial amendment for Hg-contaminated sediments. Because inorganic Hg methylation is a byproduct of bacterial sulfate reduction, reaction of Mn(iv) oxide with pore water should poise sediment oxidation potential at a level higher than favorable for Hg methylation. Changes in Mn(iv)-oxide mineralogy and oxidation state over time were investigated in sediment tank mesocosm experiments in which Mn(iv)-oxide amendment was either mixed into Hg-contaminated sediment or applied as a thin-layer sand cap on top of sediment...
November 6, 2018: Environmental Science. Processes & Impacts
M P Wilson, F Worrall, R J Davies, A Hart
An environmental concern with hydraulic fracturing (fracking) is that injected fluids or formation fluids could migrate upwards along high-permeability faults and contaminate shallow groundwater resources. However, numerical modelling has suggested that compartmentalisation by low-permeability faults may be a greater risk factor to shallow aquifers than high-permeability faults because lateral groundwater flow is reduced and upward flow through strata may be encouraged. Therefore, it is important that compartmentalisation can be adequately identified prior to fracking...
November 5, 2018: Environmental Science. Processes & Impacts
Dimitri Vlassopoulos, Masakazu Kanematsu, Elizabeth A Henry, Jessica Goin, Alexander Leven, David Glaser, Steven S Brown, Peggy A O'Day
Manganese(iv) oxide (pyrolusite, birnessite) mineral amendments can reduce dissolved MeHg concentrations in sediment theoretically by inhibiting microbial sulfate reduction, which is a major methylation pathway in sediments. Anaerobic sediment slurry microcosms in which Hg methylation was stimulated by addition of labile organic carbon (acetate) and HgCl2 showed that manganese(iv) oxide reduced the percent MeHg in slurry porewater (filtered), by 1-2 orders of magnitude relative to controls. Sediment-water mesocosms with pyrolusite or birnessite either directly mixed into the top 5 cm or applied in a thin (5 cm) sand layer over sediment showed reductions in percent MeHg in porewater of 66-69% for pyrolusite and 81-89% for birnessite amendment...
November 5, 2018: Environmental Science. Processes & Impacts
Moses A Ajemigbitse, Fred S Cannon, Mark S Klima, James C Furness, Chris Wunz, Nathaniel R Warner
Unconventional oil and gas residual solid wastes are generally disposed in municipal waste landfills (RCRA Subtitle D), but they contain valuable raw materials such as proppant sands. A novel process for recovering raw materials from hydraulic fracturing residual waste is presented. Specifically, a novel hydroacoustic cavitation system, combined with physical separation devices, can create a distinct stream of highly concentrated sand, and another distinct stream of clay from the residual solid waste by the dispersive energy of cavitation conjoined with ultrasonics, ozone and hydrogen peroxide...
November 1, 2018: Environmental Science. Processes & Impacts
Zhong-Jun Wang, Fu-Jun Yue, Si-Liang Li, Xiao-Dong Li, Shi-Lu Wang, Cai Li, Fa-Xiang Tao
Nitrogenous species, particularly nitrate, are some of the most significant contaminants in freshwater rivers and lakes in China, posing a significant threat to human and ecosystem health. To identify the major nitrate sources and transformation processes in a subtropical karst lake (Hongfeng, HF) in Southwest China, two sampling campaigns involving three lake profiles were conducted during the impoundment period (April) and flood period (August). Hydro-chemistry parameters, concentration of nitrogenous species, and dual isotopes of nitrate were analyzed...
October 25, 2018: Environmental Science. Processes & Impacts
Karina Knudsmark Sjøholm, Matias Flyckt-Nielsen, Thomas D Bucheli, Philipp Mayer
Applying WWTP sludge on arable soil has clear benefits from a resource recycling point of view but can potentially also lead to contamination of soil, agricultural products and the environment. The sludge contains a complex mixture of particularly hydrophobic organic chemicals (HOCs) that sorb to the organic matter. Equilibrium sampling was recently applied to the measurement of chemical activities of polycyclic aromatic hydrocarbons (PAHs) in secondary and digested sludge, and clear activity increases due to the anaerobic digestion treatment were observed...
October 25, 2018: Environmental Science. Processes & Impacts
Jingjing Du, Chuanyong Jing
Lake sediments are an important reservoir for toxic and hydrophobic polycyclic aromatic hydrocarbons (PAHs). Monitoring of PAHs in sediment is helpful to understand pollution mechanisms and anthropogenic activities. This study reviews studies of PAHs in lake sediments published during 2002-2018. The studies' findings are analyzed, distributions of PAHs in lake sediments are summarized, and the applicability of lake sediments for tracking changes in PAH emission sources is emphasized. Lake sediments heavily polluted with PAHs are distributed in China, Egypt, the USA, and some urban lakes in Africa...
October 25, 2018: Environmental Science. Processes & Impacts
Malte Posselt, Anna Jaeger, Jonas L Schaper, Michael Radke, Jonathan P Benskin
Hyporheic zones (HZs) are dynamic and complex transition regions between rivers and aquifers which are thought to play an important role in the attenuation of environmental micropollutants. Non-steady state and small-scale hyporheic processes which affect micropollutants in the HZ are poorly characterized due to limitations in existing analytical methodologies. In this work we developed a method for high spatio-temporal resolution analysis of polar organic micropollutants (POMs) in hyporheic pore- and surface waters by combining (semi-) automatic low volume sampling techniques with direct-injection ultra-high performance liquid chromatography tandem mass spectrometry...
October 23, 2018: Environmental Science. Processes & Impacts
Annika Jahnke, Anna Sobek, Melanie Bergmann, Jennifer Bräunig, Madlen Landmann, Sabine Schäfer, Beate I Escher
This study investigated whether cell-based bioassays were suitable to characterize profiles of mixture effects of hydrophobic pollutants in multiple sediments covering remote Arctic and tropical sites to highly populated sites in Europe and Australia. The total contamination was determined after total solvent extraction and the bioavailable contamination after silicone-based passive equilibrium sampling. In addition to cytotoxicity, we observed specific responses in cell-based reporter gene bioassays: activation of metabolic enzymes (arylhydrocarbon receptor: AhR, peroxisome proliferator activated receptor gamma: PPARγ) and adaptive stress responses (oxidative stress response: AREc32)...
October 22, 2018: Environmental Science. Processes & Impacts
Matthew Nkoom, Guanghua Lu, Jianchao Liu
The rationale behind this paper was to review the available data regarding the current knowledge on the levels and trends of pharmaceuticals and personal care products (PPCPs) in Taihu Lake. The ecological risk associated with some of the PPCPs was also assessed. 36 PPCPs have been detected in the water, sediment and biota of Taihu Lake. These contaminants primarily emanate from anthropogenic activities in and around the lake. The northern part of the lake is highly polluted as compared to other parts because it receives most effluents from wastewater treatment plants (WWTPs), and domestic and industrial waste discharge from developed cities nearby...
October 22, 2018: Environmental Science. Processes & Impacts
Subrata Paul, Nand Kishor Gour, Ramesh Chandra Deka
Oxidation of ethyl vinyl ketone (CH2CHCOCH2CH3) by an OH radical was carried out using the M06-2X/6-311++G(d,p) level of theory. For the OH-initiated oxidation of ethyl vinyl ketone (EVK), we have considered six H-atom abstractions and three addition reactions. From the energetic calculation of the species involved therein, the potential energy surface (PES) of all the reaction channels was constructed. From the energy profile, we found that the H-atom abstraction from the methylene group (-CH2-) of CH2CHCOCH2CH3 is energetically more favourable than the other H-abstraction channels...
October 19, 2018: Environmental Science. Processes & Impacts
Jessica D Rogers, E Michael Thurman, Imma Ferrer, James S Rosenblum, Morgan V Evans, Paula J Mouser, Joseph N Ryan
Polyethylene glycols (PEGs) and polypropylene glycols (PPGs) are frequently used in hydraulic fracturing fluids and have been detected in water returning to the surface from hydraulically fractured oil and gas wells in multiple basins. We identified degradation pathways and kinetics for PEGs and PPGs under conditions simulating a spill of produced water to shallow groundwater. Sediment-groundwater microcosm experiments were conducted using four produced water samples from two Denver-Julesburg Basin wells at early and late production...
October 15, 2018: Environmental Science. Processes & Impacts
Jenna L Luek, Mourad Harir, Philippe Schmitt-Kopplin, Paula J Mouser, Michael Gonsior
Hydraulic fracturing requires the injection of large volumes of fluid to extract oil and gas from low permeability unconventional resources (e.g., shale, coalbed methane), resulting in the production of large volumes of highly complex and variable waste fluids. Shale gas fluid samples were collected from two hydraulically fractured wells in Morgantown, WV, USA at the Marcellus Shale Energy and Environment Laboratory (MSEEL) and analyzed using ultrahigh resolution mass spectrometry to investigate the dissolved organic sulfur (DOS) pool...
October 10, 2018: Environmental Science. Processes & Impacts
Xiaoshu Hou, Lei Chen, Guoyuan Wei, Yongwei Gong, Zhenyao Shen
An understanding of microbial pollution characteristics is needed for stormwater reuse and development of microorganism simulations in urban stormwater. This study investigated the discharge characteristics of faecal indicator bacteria (faecal coliforms) in urban runoff by field sampling both the underlying surfaces and the stormwater pipe outlet. Faecal coliform contamination in urban runoff was found to be frequent, and the highest instantaneous concentration reached 2.42 × 106 MPN/100 ml. Faecal coliforms did not show a consistent first flush effect amongst the different surfaces sampled, and this was exacerbated under rainfall events with high intensity...
October 5, 2018: Environmental Science. Processes & Impacts
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