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Environmental Science. Processes & Impacts

Marika Nell, Damian E Helbling
Hydraulic fracturing (HF) operations utilize millions of gallons of water amended with chemical additives including biocides, corrosion inhibitors, and surfactants. Fluids injected into the subsurface return to the surface as wastewaters, which contain a complex mixture of additives, transformation products, and geogenic chemical constituents. Quantitative analytical methods are needed to evaluate wastewater disposal alternatives or to conduct adequate exposure assessments. However, our narrow understanding of how matrix effects change the ionization efficiency of target analytes limits the quantitative analysis of polar to semi-polar HF additives by means of liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS)...
May 23, 2018: Environmental Science. Processes & Impacts
Eliana Tassi, Martina Grifoni, Fabrizio Bardelli, Giuliana Aquilanti, Sonia La Felice, Antonella Iadecola, Pierfranco Lattanzi, Gianniantonio Petruzzelli
The problem of high levels of chromium is one of the most important issues in soils of the Mediterranean area, in particular those deriving from ophiolitic parent materials. Very often the chromium concentration is greater than the threshold values of legislation on soil pollution and the knowledge of the origin of contamination (natural or anthropogenic) is important to formulate risk characterization. This study evaluated the soils from three coastal areas of the Cecina Valley (Tuscany, Italy) to understand the origin of chromium in the soils, where high levels of hexavalent chromium were found in well and spring waters of the areas...
May 23, 2018: Environmental Science. Processes & Impacts
Hollie Ashworth, Liam Abrahamsen-Mills, Nick Bryan, Lynn Foster, Jonathan R Lloyd, Simon Kellet, Sarah Heath
One of the nuclear fuel storage ponds at Sellafield (United Kingdom) is open to the air, and has contained a significant inventory of corroded magnox fuel and sludge for several decades. As a result, some fission products have also been released into solution. 90Sr is known to constitute a small mass of the radionuclides present in the pond, but due to its solubility and activity, it is at risk of challenging effluent discharge limits. The sludge is predominantly composed of brucite (Mg(OH)2), and organic molecules are known to be present in the pond liquor with occasional algal blooms restricting visibility...
May 18, 2018: Environmental Science. Processes & Impacts
Wen-Xiong Wang, Jie Meng, Nanyan Weng
Oysters are important benthic bivalves in coastal and estuarine environments. They are widely farmed due to their rapid growth and taste; they are also widely applied in environmental monitoring of coastal pollution due to their accumulation of contaminants. Most importantly, oysters are among the few marine organisms that are considered to be hyper-accumulators of many toxic metals, such as cadmium, copper and zinc. As such, there is a tremendous call to study the interactions between metals and oysters, especially due to the increasing metal pollution in many coastal and estuarine waters...
May 18, 2018: Environmental Science. Processes & Impacts
Joseph A Needoba, Paul G Tratnyek
No abstract text is available yet for this article.
May 16, 2018: Environmental Science. Processes & Impacts
Yuzhen Liang, Lei Tian, Yang Lu, Lanfang Peng, Pei Wang, Jingyi Lin, Tao Cheng, Zhi Dang, Zhenqing Shi
The kinetics of Cd(ii) adsorption/desorption on ferrihydrite is an important process affecting the fate, transport, and bioavailability of Cd(ii) in the environment, which was rarely systematically studied and understood at quantitative levels. In this work, a combination of stirred-flow kinetic experiments, batch adsorption equilibrium experiments, high-resolution transmission electron microscopy (HR-TEM), and mechanistic kinetic modeling were used to study the kinetic behaviors of Cd(ii) adsorption/desorption on ferrihydrite...
May 15, 2018: Environmental Science. Processes & Impacts
Bo Shen, Xianghua Wen, Gregory V Korshin
Herein, the rotating disk electrode technique was used for the first time to investigate the effects of mass-transfer limitations and pH on the electrochemical oxidation of CPX, to determine the kinetics of CPX oxidation and to explore intrinsic mechanisms during the electron transfer process. Firstly, cyclic voltammetry revealed that an obvious irreversible CPX oxidation peak was observed within the potential window from 0.70 to 1.30 V at all pHs. Based on the Levich equation, the electrochemical oxidation of CPX in the electron transfer process was found to be controlled by both diffusion and kinetic processes when pH = 2, 5, 7 and 9; the diffusion coefficient of CPX at pH = 2 was calculated to be 1...
May 14, 2018: Environmental Science. Processes & Impacts
Zhen Yu, Huiling Wei, Rui Hao, Huashuo Chu, Yi Zhu
Cadmium (Cd) is a nonessential and toxic trace element widely existing in waters through various anthropogenic activities such as mining and waste disposal. The physiological responses of aquatic organisms to long-term Cd exposure at environmentally relevant concentrations are still not well explored. In the present study, two strains of unicellular green algae Chlamydomonas reinhardtii, a walled strain CC125 and a wall-less strain CC406 were selected to investigate the physiological changes of aquatic organisms after long-term Cd exposure at environmentally relevant concentrations (4...
May 4, 2018: Environmental Science. Processes & Impacts
Kai Bittermann, Lukas Linden, Kai-Uwe Goss
Currently the bioaccumulation potential of organic chemicals is assessed in a first tier approach via their octanol-water partition coefficient. This approach has been developed for neutral chemicals and cannot work for ionizable and ionic chemicals because the latter have different sorption-mechanisms and -preferences. Thus, suitable screening tools for the bioconcentration potential of ionic and ionizable chemicals need to be developed because it cannot be expected that these chemicals are non-bioaccumulative per se...
May 1, 2018: Environmental Science. Processes & Impacts
Lakmini P Egodawatta, Gabriella K Macoustra, Lien K Ngo, Dianne F Jolley
Elevated concentrations of As and Sb impact environmental quality and human health. In this study total and bioavailable As and Sb were measured from recently and historically contaminated soils and the phytotoxicity of these soils was evaluated with Ipomoea aquatica (35-d exposure from germination) using biomass, length of plant tissues and photosynthetic efficiency. As and Sb were both present within the soil (co-contaminated). The bioavailable As and Sb in soils were determined by a Sequential Extraction Procedure (SEP) and compared to total soil concentrations and bioaccumulation in the edible parts of I...
April 25, 2018: Environmental Science. Processes & Impacts
Kai Zheng, Heping Li, Luying Wang, Xiaoying Wen, Qingyou Liu
Galena can be easily weathered under acid rain conditions and causes environmental issues. This process, in nature, is an electrochemical process. In situ electrochemical technology and surface analysis technology were combined to investigate this weathering process. The experimental results showed that galena weathering under simulated acid rain (SAR) could cause an initial increase in Pb2+ ions and result in the formation of a passive S0 film, and the terminal product was SO42-. Increased acidity stimulates galena weathering, and the promotion efficiency was 2208% as the pH of the SAR decreased from 5...
April 23, 2018: Environmental Science. Processes & Impacts
Yuzhen Liang, Tifany L Torralba-Sanchez, Dominic M Di Toro
Polyparameter Linear Free Energy Relationships (pp-LFERs) using Abraham system parameters have many useful applications. However, developing the Abraham system parameters depends on the availability and quality of the Abraham solute parameters. Using Quantum Chemically estimated Abraham solute Parameters (QCAP) is shown to produce pp-LFERs that have lower root mean square errors (RMSEs) of predictions for solvent-water partition coefficients than parameters that are estimated using other presently available methods...
April 18, 2018: Environmental Science. Processes & Impacts
Kaibo Huang, Guining Lu, Zhiqiang Zheng, Rui Wang, Ting Tang, Xueqin Tao, Ruibing Cai, Zhi Dang, Pingxiao Wu, Hua Yin
Currently, photodegradation has been proven to be an important way of eliminating polybrominated diphenyl ethers (PBDEs) from the environment. However, the mechanism of PBDE photodegradation in surfactants by UV light is still unclear. In this study, 2,4,4'-tribrominated diphenyl ether (BDE-28) was selected as the target pollutant to investigate the photodegradation of PBDEs in Triton X-100 (TX-100), sodium dodecylbenzenesulfonate (SDBS) and cetyltrimethylammonium bromide (CTAB) solutions. All photolysis experiments were performed above the critical micelle concentration (CMC)...
April 17, 2018: Environmental Science. Processes & Impacts
Heileen Hsu-Kim, Chris S Eckley, Noelle E Selin
No abstract text is available yet for this article.
April 16, 2018: Environmental Science. Processes & Impacts
Nadeem Ali, Iqbal Mohammad Ibrahim Ismail, Mohammad W Kadi, Hussain Mohammed Salem Ali Albar
Indoor settled dust particles are considered as an important source of human exposure to chemicals such as organophosphate flame retardants (PFRs). In recent decades the Kingdom of Saudi Arabia (KSA) has experienced tremendous growth in population, as a result the number of masjids has also increased significantly to provide sufficient space for the public to offer prayers. The hospitality industry in KSA is also expanding to cater for the ever-increasing number of pilgrims visiting the two holy cities of the kingdom...
April 9, 2018: Environmental Science. Processes & Impacts
Dean Song, Hanyang Cheng, Xiaohua Jiang, Huiqing Sun, Fanyu Kong, Rongning Liang, Zhimin Qiang, Huijuan Liu, Jiuhui Qu
Quinclorac, a widely used herbicide in agriculture, has been recognized as an emerging environmental pollutant owing to its long persistence and potential risk to humans. However, no related information is available on the degradation of quinclorac by employing oxidants. Herein, the reactivity of quinclorac with permanganate was systematically investigated in water by combining experimental and computational approaches. The reaction followed overall second-order kinetics pointing to a bimolecular rate-limiting step...
April 5, 2018: Environmental Science. Processes & Impacts
Nicholas J Herkert, Keri C Hornbuckle
Accurate and precise interpretation of concentrations from polyurethane passive samplers (PUF-PAS) is important as more studies show elevated concentrations of PCBs and other semivolatile air toxics in indoor air of schools and homes. If sufficiently reliable, these samplers may be used to identify local sources and human health risks. Here we report indoor air sampling rates (Rs) for polychlorinated biphenyl congeners (PCBs) predicted for a frequently used double-dome and a half-dome PUF-PAS design. Both our experimentally calibrated (1...
April 3, 2018: Environmental Science. Processes & Impacts
W Charles Kerfoot, Noel R Urban, Cory P McDonald, Huanxin Zhang, Ronald Rossmann, Judith A Perlinger, Tanvir Khan, Ashley Hendricks, Mugdha Priyadarshini, Morgan Bolstad
A geographic enigma is that present-day atmospheric deposition of mercury in the Upper Peninsula of Michigan is low (48%) and that regional industrial emissions have declined substantially (ca. 81% reduction) relative to downstate. Mercury levels should be declining. However, state (MDEQ) surveys of rivers and lakes revealed elevated total mercury (THg) in Upper Peninsula waters and sediment relative to downstate. Moreover, Western Upper Peninsula (WUP) fish possess higher methyl mercury (MeHg) levels than Northern Lower Peninsula (NLP) fish...
March 29, 2018: Environmental Science. Processes & Impacts
Abha Parajulee, Ying Duan Lei, Xiaoshu Cao, David S McLagan, Leo W Y Yeung, Carl P J Mitchell, Frank Wania
The presence of pesticides in streams in winter, five to six years following bans on their municipal use suggests that complicated transport behaviour, such as subsurface retention and/or accumulation of pesticides and its release during storms, could be important for understanding recovery time frames following bans or legislation that aim to reduce chemical inputs. We investigated late fall and winter dynamics of four herbicides in paired urban and rural watersheds in Toronto, Canada during rainfall and snowmelt...
March 26, 2018: Environmental Science. Processes & Impacts
Kylie Wheelock, Junfeng Jim Zhang, Rob McConnell, Deliang Tang, Heather E Volk, Ya Wang, Julie B Herbstman, Shuang Wang, David H Phillips, David Camann, Jicheng Gong, Frederica Perera
Polycyclic aromatic hydrocarbons (PAH) are ubiquitous air pollutants associated with negative impacts on growth, development and behavior in children. Source-specific biological markers of PAH exposure are needed for targeting interventions to protect children. Nitro-derivatives of PAH can act as markers of exposure to diesel exhaust, gasoline exhaust, or general combustion sources. Using a novel HPLC-APCI-MS/MS detection method, we examined four hemoglobin (Hb) adducts of nitro-PAH metabolites and the Hb adduct of a benzo[a]pyrene (BaP) metabolite in 22 umbilical cord blood samples...
March 21, 2018: Environmental Science. Processes & Impacts
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