Read by QxMD icon Read


Doug Crump, Kim Williams, Suzanne Chiu, Yifeng Zhang, Jonathan W Martin
Petroleum coke or "petcoke" is a granular carbonaceous material produced during the upgrading of heavy crude oils, including bitumen. Petcoke dust was recently reported as an environmental contaminant in the Athabasca oil sands region, but the ecotoxicological hazards posed by this complex bitumen-derived material - including those to avian species - have not been characterized. In this study, solvent extracts (x) of delayed and fluid petcoke (xDP and xFP) were prepared and dissolved in dimethylsulfoxide. A water accommodated fraction of delayed petcoke (waDP) was also prepared...
April 28, 2017: Environmental Science & Technology
Carlos A Manzano, Christopher H Marvin, Derek C G Muir, Tom Harner, Jonathan W Martin, Yifeng Zhang
The aromatic fractions of snow, lake sediment, and air samples collected during 2011-2014 in the Athabasca Oil Sands Region were analyzed using two-dimensional gas chromatography following a non-targeted approach. Commonly monitored aromatics (parent and alkylated-polycyclic aromatic hydrocarbons, dibenzothiophenes) were excluded from the analysis, focusing mainly on other heterocyclic aromatics. The unknowns detected were classified into isomeric groups, and tentatively identified using mass spectral libraries...
April 28, 2017: Environmental Science & Technology
Tigran Margossian, Kim Larmier, Sung Min Kim, Frank Krumeich, Alexey Fedorov, Peter Chen, Christoph Mueller, Christophe Copéret
Syngas production via the Dry Reforming of Methane (DRM) is a highly endothermic process conducted under harsh conditions, hence the main difficulty resides in generating stable catalysts. This can in principle be achieved by reducing coke formation, sintering and loss of metal through diffusion in the support. [{Ni(μ2-OCHO)(OCHO)(tmeda)}2(μ2-OH2)], readily synthesized and soluble in a broad range of solvents, was developed as a molecular precursor to form pure 2 nm Ni(0) nanoparticles on alumina, the commonly used support in DRM...
April 26, 2017: Journal of the American Chemical Society
Liu Shi, Dong Wang, Di Cao, Chunhong Na, Xie Quan, Ying Zhang
The anaerobic-anoxic-oxic (A/A/O) process is the commonly used biological wastewater treatment process, especially for the coking wastewater. However, limit is known about its ability in bio-toxicity removal from wastewater. In this study, we evaluated the performance of A/A/O process in bio-toxicity removal from the coking wastewater, using two test species (i.e. crustacean (Daphnia magna) and zebra fish (Danio rerio)) in respect of acute toxicity, oxidative damage and genotoxicity. Our results showed that the acute toxicity of raw influent was reduced gradually along with A/A/O process and the effluent presented no acute toxicity to Daphnia magna (D...
April 21, 2017: Ecotoxicology and Environmental Safety
Margarita A Dmitrienko, Pavel A Strizhak
High concentrations of hazardous anthropogenic emissions (sulfur, nitrogen and carbon oxides) from solid fuel combustion in coal burning plants cause environmental problems that have been especially pressing over the last 20-30 years. A promising solution to these problems is a switch from conventional pulverized coal combustion to coal-water slurry fuel. In this paper, we pay special attention to the environmental indicators characterizing the combustion of different coal ranks (gas, flame, coking, low-caking, and nonbaking coals) and coal-water slurry fuels based on the coal processing waste - filter cakes...
April 20, 2017: Science of the Total Environment
Jili Tao, Qinru Fan, Longhua Ma
A new linear quadratic regulation (LQ) control plus a proportional (P) control system is proposed for the level regulation in an industrial coke fractionation tower. The process is first stabilized using a P controller and then a subsequent LQ controller is designed for the P control system. The P control system is modeled as a generalized first order plus dead time (FOPDT) process using step-response test and the LQ-P controller is designed through a new state space structure. Performance in terms of regulatory and servo issues were investigated...
April 17, 2017: ISA Transactions
Yuefeng He, Jun Qi, Fang He, Yongchang Zhang, Youlian Wang, Ruobing Zhang, Gang Li
OBJECTIVES: This study investigated whether variations in GSTT1 and GSTM1 gene are associated with the DNA damage level of p53 gene. METHODS: We quantified urinary 1-hydroxypyrene using high-performance liquid chromatography, and examined the DNA damage level of p53 gene by real-time quantitative PCR in 756 coke-oven workers. Multiplex PCR was used to detect the presence or absence of genes. RESULTS: DNA damage levels of p53 gene in the high exposure group and intermediate exposure group were significantly higher than that of p53 gene in the low exposure group (P < 0...
April 19, 2017: Journal of Occupational and Environmental Medicine
Weifeng Tu, Mireille Ghoussoub, Chandra Veer Singh, Ya-Huei Cathy Chin
This study describes a new C-H bond activation pathway during CH4-CO2 reactions on oxophilic Ni-Co and Co clusters, unlike those established previously on Ni clusters. The initial C-H bond activation remains as the sole kinetically relevant step on Ni-Co, Ni, and Co clusters, but their specific reaction path varies. On Ni clusters, C-H bond activation occurs via an oxidative addition step that involves a three center (H3C∙∙∙*∙∙∙H)(‡) transition state, during which a Ni atom inserts into the C-H bond and donates its electron density into the C-H bond anti-bonding orbital...
April 17, 2017: Journal of the American Chemical Society
Lingqian Meng, Xiaochun Zhu, Emiel J M Hensen
Fe/ZSM-5 nanosheet zeolites of varying thickness were synthesized with di- and tetraquaternary ammonium structure directing agents and extensively characterized for their textural, structural, and catalytic properties. Introduction of Fe(3+) ions in the framework of nanosheet zeolites was slightly less effective than in bulk ZSM-5 zeolite. Steaming was necessary to activate all catalysts for N2O decomposition and benzene oxidation. The higher the Fe content, the higher the degree of Fe aggregation was after catalyst activation...
April 7, 2017: ACS Catalysis
Chao Chai, Qiqi Cheng, Juan Wu, Lusheng Zeng, Qinghua Chen, Xiangwei Zhu, Dong Ma, Wei Ge
The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were analyzed in soil (n=196) and vegetable (n=30) collected from greenhouses, and also in the soil (n=27) collected from agriculture fields close to the greenhouses in Shandong Province, China. The total PAH concentration (∑16PAH) ranged from 152.2µg/kg to 1317.7µg/kg, within the moderate range in agricultural soils of China. Three-ring PAHs were the dominant species, with Phe (16.3%), Ace (13.1%), and Fl (10.5%) as the major compounds. The concentrations of low molecular weight (LMW ≤3 rings) PAHs were high in the east and north of Shandong, while the concentrations of high molecular weight (HMW ≥4 rings) PAHs were high in the south and west of the study area...
April 12, 2017: Ecotoxicology and Environmental Safety
Humberto Reyes B
No abstract text is available yet for this article.
November 2016: Revista Médica de Chile
Konstantin von Gunten, Md Samrat Alam, Magdalena Hubmann, Yong Sik Ok, Kurt O Konhauser, Daniel S Alessi
A modified Community Bureau of Reference (CBR) sequential extraction method was tested to assess the composition of untreated pyrogenic carbon (biochar) and oil sands petroleum coke. Wood biochar samples were found to contain lower concentrations of metals, but had higher fractions of easily mobilized alkaline earth and transition metals. Sewage sludge biochar was determined to be less recalcitrant and had higher total metal concentrations, with most of the metals found in the more resilient extraction fractions (oxidizable, residual)...
March 29, 2017: Bioresource Technology
Victoria B F Custodis, Patrick Hemberger, Jeroen A van Bokhoven
One of the key challenges in renewable chemical production is the conversion of lignin, especially by fast pyrolysis. The complexity of the lignin pyrolysis process has prevented the identification of the mechanism, inhibiting further industrial implementation. By combining pyrolysis of model compounds (4-phenoxyphenol and 2-methoxy-phenoxybenzene) with bonds characteristic of lignin under vacuum and realistic pressure conditions, the roles of inter- and intramolecular reactions were established. On the one hand the stable 4-O-5 ether bond enables, without breaking, C-C bond formation within diphenyl ethers and even directly forms naphthalene depending on the position and type of the substituent...
April 7, 2017: Chemistry: a European Journal
Paola Ferrini, Steven-Friso Koelewijn, Joost Van Aelst, Nicolas Nuttens, Bert F Sels
Alternative biobased bisphenols from lignocellulosic biomass are not only favorable to reduce the environmental impact of current petroleum-derived plastics, but they can be simultaneously beneficial for health issues related to bisphenol A (BPA). Additionally, conventional BPA synthesis entails a large excess of unrecoverable homogeneous acid catalyst (e.g., HCl) or unrecyclable thermolabile sulfonated resins. In this report, zeolites are proposed as recoverable and thermally stable solid acids for the Brønsted-acid-catalyzed condensation between 4-methylguaiacol and formaldehyde to selectively produce renewable bisphenols...
April 4, 2017: ChemSusChem
Beiming Cai, Chencheng Wang, Bing Zhang
The impact of virtual water flows on regional water scarcity in China had been deeply discussed in previous research. However, these studies only focused on water quantity, the impact of virtual water flows on water quality has been largely neglected. In this study, we incorporate the blue water footprint related with water quantity and grey water footprint related with water quality into virtual water flow analysis based on the multiregional input-output model of 2007. The results find that the interprovincial virtual flows accounts for 23...
March 30, 2017: Journal of Environmental Management
Reuven B Simhayov, Jonathan S Price, Christina M Smeaton, Chris Parsons, Fereidoun Rezanezhad, Philippe Van Cappellen
Overburden and tailings materials from oil sands production were used as construction materials as part of a novel attempt to create a self-sustaining, peat accumulating fen-upland ecosystem. To evaluate the potential for elemental release from the construction materials, total elemental concentrations in the tailings sand, petroleum coke and peat used to construct a fen ecosystem were determined using microwave-assisted acid digestions and compared to a leaching experiment conducted under environmentally-relevant conditions...
March 30, 2017: Environmental Pollution
Zhini He, Daochuan Li, Junxiang Ma, Liping Chen, Huawei Duan, Bo Zhang, Chen Gao, Jie Li, Xiumei Xing, Jian Zhao, Shan Wang, Fangping Wang, Haiyan Zhang, Huiyao Li, Shen Chen, Xiaowen Zeng, Qing Wang, Yongmei Xiao, Yuxin Zheng, Wen Chen
Long term exposure to polycyclic aromatic hydrocarbons (PAHs) is associated with the increasing risk of lung cancer. To identify differentially hypermethylated genes associated with PAHs-induced carcinogenicity, we performed genome-wide DNA methylation analysis in 20 μM benzo(a)pyrene (BaP)-transformed human bronchial epithelial (HBE) cells at different stages of cell transformation. Several methylated genes (CNGA4, FLT1, GAREM1, SFMBT2, TRIM36) were differentially hypermethylated and their mRNA was suppressed in cells at both pre-transformed and transformed stages...
March 27, 2017: Environmental Pollution
Muhammad Ahmad, Sitong Liu, Nasir Mahmood, Asif Mahmood, Muhammad Ali, Maosheng Zheng, Jinren Ni
Coking wastewater contains not only high-strength nitrogen but also toxic biorefractory organics. This study presents simultaneous removal of high-strength quinoline, carbon, and ammonium in coking wastewater by immobilized bacterial communities composed of a heterotrophic strain Pseudomonas sp. QG6 (hereafter referred as QG6), ammonia-oxidizing bacteria (AOB), and anaerobic ammonium oxidation bacteria (anammox). The bacterial immobilization was implemented with the help of a self-designed porous cubic carrier that created structured microenvironments including an inner layer adapted for anaerobic bacteria, a middle layer suitable for coaggregation of certain aerobic and anaerobic bacteria, and an outer layer for heterotrophic bacteria...
April 6, 2017: ACS Applied Materials & Interfaces
Manikandan Krishnamurthy, Paramesh Ramalingam, Kumaravel Perumal, Latha Perumal Kamalakannan, Jeremiah Chinnadurai, Rekha Shanmugam, Krishnan Srinivasan, Vidhya Venugopal
BACKGROUND: Workers laboring in steel industries in tropical settings with high ambient temperatures are subjected to thermally stressful environments that can create well-known risks of heat-related illnesses and limit workers' productivity. METHODS: A cross-sectional study undertaken in a steel industry in a city nicknamed "Steel City" in Southern India assessed thermal stress by wet bulb globe temperature (WBGT) and level of dehydration from urine color and urine specific gravity...
March 2017: Safety and Health At Work
Deni Mance, Johan van der Zwan, Marjolein E Z Velthoen, Florian Meirer, Bert M Weckhuysen, Marc Baldus, Eelco T C Vogt
A combination of solid-state NMR techniques supported by EPR and SEM-EDX experiments was used to localize different carbon species (coke) in commercial fluid catalytic cracking catalysts. Aliphatic coke species formed during the catalytic process and aromatic coke species deposited directly from the feedstock respond differently to dynamic nuclear polarization signal enhancement in integral and crushed FCC particles, indicating that aromatic species are mostly concentrated on the outside of the catalyst particles, whereas aliphatic species are also located on the inside of the FCC particles...
March 22, 2017: Chemical Communications: Chem Comm
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"