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Environmental Science. Processes & Impacts

James M Cash, Mathew R Heal, Ben Langford, Julia Drewer
The atmospheric reactions leading to the generation of secondary organic aerosol (SOA) from the oxidation of isoprene are generally assumed to produce only racemic mixtures, but aspects of the chemical reactions suggest this may not be the case. In this review, the stereochemical outcomes of published isoprene-degradation mechanisms contributing to high amounts of SOA are evaluated. Despite evidence suggesting isoprene first-generation oxidation products do not contribute to SOA directly, this review suggests the stereochemistry of first-generation products may be important because their stereochemical configurations may be retained through to the second-generation products which form SOA...
October 20, 2016: Environmental Science. Processes & Impacts
Mingkai Qu, Weidong Li, Chuanrong Zhang, Biao Huang, Yongcun Zhao
To effectively understand the availability of soil nitrogen and assist in soil nitrogen control at the regional scale, it is essential to understand the accurate spatial distribution patterns of the three soil nitrogen parameters [i.e., total nitrogen (TN), available nitrogen (AN) and nitrogen availability ratio (NAR)] and explore the spatially varying influences of major impact factors on soil AN. Land use affects the spatial distributions of soil TN, AN and NAR (i.e., AN/TN). To explore the effects of different land use types and improve mapping accuracy, residual kriging with land use information and ordinary kriging (without land use information) were compared based on the sample data of soil TN and AN in Hanchuan county, China...
October 20, 2016: Environmental Science. Processes & Impacts
Ouarda Merdoud, Claudio Cameselle, Mohamed Oualid Boulakradeche, Djamal Eddine Akretche
The soil from an industrial area in Algeria was contaminated with Cr (8370 mg kg(-1)), Ni (1135 mg kg(-1)) and zinc (1200 mg kg(-1)). The electrodialytic remediation of this soil was studied using citric acid and EDTA as facilitating agents. 0.1 M citric acid or EDTA was added directly to the soil before it was introduced in an electrodialytic cell in an attempt to enhance the heavy metal solubility in the interstitial fluid. The more acidic pH in the soil when citric acid was used as the facilitating agent was not enough to mobilize and remove the metals from the soil...
October 14, 2016: Environmental Science. Processes & Impacts
Pete Smith, R Stuart Haszeldine, Stephen M Smith
The aggregate technical potential for land-based negative emissions technologies (NETs) in the UK is estimated to be 12-49 Mt C eq. per year, representing around 8-32% of current emissions. The proportion of this potential that could be realized is limited by a number of cost, energy and environmental constraints which vary greatly between NETs.
October 12, 2016: Environmental Science. Processes & Impacts
Kristopher McNeill, Silvio Canonica
Excited triplet states of chromophoric dissolved organic matter ((3)CDOM*) play a major role among the reactive intermediates produced upon absorption of sunlight by surface waters. After more than two decades of research on the aquatic photochemistry of (3)CDOM*, the need for improving the knowledge about the photophysical and photochemical properties of these elusive reactive species remains considerable. This critical review examines the efforts to date to characterize (3)CDOM*. Information on (3)CDOM* relies mainly on the use of probe compounds because of the difficulties associated with directly observing (3)CDOM* using transient spectroscopic methods...
October 7, 2016: Environmental Science. Processes & Impacts
Grace E Schwartz, Lauren K Redfern, Kaoru Ikuma, Claudia K Gunsch, Laura S Ruhl, Avner Vengosh, Heileen Hsu-Kim
Mercury (Hg) associated with coal ash is an environmental concern, particularly if the release of coal ash to the environment is associated with the conversion of inorganic Hg to methylmercury (MeHg), a bioaccumulative form of Hg that is produced by anaerobic microorganisms. In this study, sediment slurry microcosm experiments were performed to understand how spilled coal ash might influence MeHg production in anaerobic sediments of an aquatic ecosystem. Two coal ash types were used: (1) a weathered coal ash; and (2) a freshly collected, unweathered fly ash that was relatively enriched in sulfate and Hg compared to the weathered ash...
October 5, 2016: Environmental Science. Processes & Impacts
Ehsan Maghsoudi, Nathalie Fortin, Charles Greer, Christine Maynard, Antoine Pagé, Sung Vo Duy, Sébastien Sauvé, Michèle Prévost, Sarah Dorner
A bacterium capable of degrading five microcystin (MC) variants, microcystin-LR, YR, LY, LW and LF at an initial total concentration of 50 μg l(-1) in less than 16 hours was isolated from Missisquoi Bay, in the south of Quebec, Canada. Phylogenetic analysis of the 16S rRNA gene sequence identified the bacterium as Sphingopyxis sp., designated strain MB-E. It was shown that microcystin biodegradation activity was reduced at acidic and basic pH values. Even though no biodegradation occurred at pH values of 5...
October 3, 2016: Environmental Science. Processes & Impacts
Rachel M Adams, Brandon C McAdams, William A Arnold, Yu-Ping Chin
Non-point source pesticide pollution is a concern for wetlands in the prairie pothole region (PPR). Recent studies have demonstrated that reduced sulfur species (e.g., bisulfide and polysulfides) in PPR wetland pore waters directly undergo reactions with chloroacetanilide and dinitroaniline compounds. In this paper, the abiotic transformation of two organophosphate compounds, chlorpyrifos and chlorpyrifos-methyl, was studied in PPR wetland pore waters. Chlorpyrifos-methyl reacted significantly faster (up to 4 times) in pore water with reduced sulfur species relative to hydrolysis...
September 30, 2016: Environmental Science. Processes & Impacts
J Mark Parnis, Donald Mackay
A series of 12 oligomeric models for polydimethylsiloxane (PDMS) were evaluated for their effectiveness in estimating the PDMS-water partition ratio, KPDMS-w. Models ranging in size and complexity from the -Si(CH3)2-O- model previously published by Goss in 2011 to octadeca-methyloctasiloxane (CH3-(Si(CH3)2-O-)8CH3) were assessed based on their RMS error with 253 experimental measurements of log KPDMS-w from six published works. The lowest RMS error for log KPDMS-w (0.40 in log K) was obtained with the cyclic oligomer, decamethyl-cyclo-penta-siloxane (D5), (-Si(CH3)2-O-)5, with the mixing-entropy associated combinatorial term included in the chemical potential calculation...
September 14, 2016: Environmental Science. Processes & Impacts
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October 12, 2016: Environmental Science. Processes & Impacts
(no author information available yet)
No abstract text is available yet for this article.
October 12, 2016: Environmental Science. Processes & Impacts
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No abstract text is available yet for this article.
October 12, 2016: Environmental Science. Processes & Impacts
Yulin Jiang, Jianfu Zhao, Penghui Li, Qinghui Huang
Because of the significance in photosynthesis, nutrient dynamics, trophodynamics and biological activity, dissolved organic matter (DOM) is important to the microbial community in the coastal plume zone. In this study, we investigated the hydrodynamic processes, photodegradation and biodegradation of DOM at the Yangtze River plume in the East China Sea through analyzing water quality and optical properties of DOM. Surface water samples were collected to examine water quality and fluorescence properties of fluorescent dissolved organic matter (FDOM)...
October 12, 2016: Environmental Science. Processes & Impacts
Geun-Hye Yu, Seungshik Park, Kwon-Ho Lee
In this study, 24 h size-segregated particulate matter (PM) samples were collected between September 2012 and August 2013 at an urban site in Korea to investigate seasonal mass size distributions of PM and its water-soluble components as well as to infer the possible sources of size-resolved water-soluble organic carbon (WSOC) using a positive matrix factorization (PMF) model. The potential source contribution function (PSCF) was also computed to identify the possible source regions of size-resolved WSOC. The seasonal average contribution of water-soluble organic matter to PM1...
October 12, 2016: Environmental Science. Processes & Impacts
Jordyn M Wolfand, Gregory H LeFevre, Richard G Luthy
Fipronil is a recalcitrant phenylpyrazole-based pesticide used for flea/tick treatment and termite control that is distributed in urban aquatic environments via stormwater and contributes to stream toxicity. We discovered that fipronil is rapidly metabolized (t1/2 = 4.2 d) by the white rot fungus Trametes versicolor to fipronil sulfone and multiple previously unknown fipronil transformation products, lowering fipronil concentration by 96.5%. Using an LC-QTOF-MS untargeted metabolomics approach, we identified four novel fipronil fungal transformation products: hydroxylated fipronil sulfone, glycosylated fipronil sulfone, and two compounds with unresolved structures...
October 12, 2016: Environmental Science. Processes & Impacts
Ying Lan, Andrew S Elwood Madden, Elizabeth C Butler
Trichloroethylene (TCE) and tetrachloroethylene (PCE) are common ground water contaminants susceptible to reductive dechlorination by FeS (mackinawite) in anaerobic environments. The objective of this study was to characterize the mineral-associated products that form when mackinawite reacts with TCE and PCE. The dissolved products of the reaction included Cl(-) and Fe(2+), and trace amounts of cis 1,2-dichloroethylene (for TCE) and TCE (for PCE). Selected area electron diffraction (SAED) analysis identified greigite as a mackinawite oxidation product formed after reaction between TCE or PCE and FeS over seven weeks...
October 12, 2016: Environmental Science. Processes & Impacts
Damien Johann Bolinius, Matthew MacLeod, Michael S McLachlan, Philipp Mayer, Annika Jahnke
The capacity of leaves to take up chemicals from the atmosphere and water influences how contaminants are transferred into food webs and soil. We provide a proof of concept of a passive dosing method to measure leaf/polydimethylsiloxane partition ratios (Kleaf/PDMS) for intact leaves, using polychlorinated biphenyls (PCBs) as model chemicals. Rhododendron leaves held in contact with PCB-loaded PDMS reached between 76 and 99% of equilibrium within 4 days for PCBs 3, 4, 28, 52, 101, 118, 138 and 180. Equilibrium Kleaf/PDMS extrapolated from the uptake kinetics measured over 4 days ranged from 0...
October 12, 2016: Environmental Science. Processes & Impacts
D A Raftos, A R Melwani, P A Haynes, S Muralidharan, G F Birch, V Amaral, E L Thompson, D A Taylor
Correction for 'The biology of environmental stress: molecular biomarkers in Sydney rock oysters (Saccostrea glomerata)' by D. A. Raftos et al., Environ. Sci.: Processes Impacts, 2016, 18, 1129-1139.
October 12, 2016: Environmental Science. Processes & Impacts
Cong Xiao, Teng Ma, Yao Du, Haotian Yu, Shuai Shen
Muddy sediments are abundant in pore water and capable of preserving a large amount of chemicals, such as arsenic. Muddy sediments would transform into aquicludes or aquitards during long-term compaction and burial. It remains unclear whether the release of arsenic from muddy sediments poses a potential contamination risk to groundwater in the adjacent aquifer. An indoor compaction simulation experiment was conducted, coupled with an investigation on vertical geochemical profiles of muddy sediments in one actual borehole...
October 12, 2016: Environmental Science. Processes & Impacts
Scott C Anderson, Amy Christiansen, Alexa Peterson, Logan Beukelman, Amanda M Nienow
The photodegradation rate of the herbicide imazethapyr on epicuticular waxes of soybean and corn plants was investigated. Plant age, relative humidity, temperature, and number of light banks were varied during plant growth, analyzed statistically, and examined to determine if these factors had an effect on the photodegradation of imazethapyr. Through ultraviolet/visible (UV-Vis) and fluorescence spectroscopy, epicuticular wax characteristics of soybean and corn plants were explored, were used to confirm observations determined statistically, and explain correlations between the rate constants and the composition of the epicuticular waxes...
October 12, 2016: Environmental Science. Processes & Impacts
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