- The Effect of Trimebutine on the Overlap Syndrome Model of Guinea Pigs. [Journal Article]
- JNJ Neurogastroenterol Motil 2018 Aug 16
- CONCLUSIONS: Trimebutine has been demonstrated to be effective on both upper and lower GI motorfunction in peripheral CRF induced OS model. Therefore, trimebutine might be an effectivedrug for the treatment of OS between FD and IBS patients.
- Urban soils impacted by tailings from coal mining: PAH source identification by 59 PAHs, BPCA and alkylated PAHs. [Journal Article]
- EPEnviron Pollut 2018 Aug 07; 242(Pt B):1217-1225
- Urban soils in mining and industrial regions like the Ruhr Area are characterized by admixtures of anthropogenic substrates, e. g. tailings, coals, ashes, debris or scoria. These soils often show ele...
Urban soils in mining and industrial regions like the Ruhr Area are characterized by admixtures of anthropogenic substrates, e. g. tailings, coals, ashes, debris or scoria. These soils often show elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) which are commonly attributed to non-point pyrogenic carbon sources like soot and particulate matter. An emission source of PAHs into urban soils in these regions, that surprisingly is still largely neglected, are the millions of tons of tailings from underground coal mining that have been used as material for road construction, terrain leveling, river channeling and support of embankments. Here we classify the PAH sources of 13 urban soils as either petrogenic or pyrogenic. The soils contained (1) tailings, (2) ashes and (3) different anthropogenic substrates. The classification is based on a comprehensive analysis of 59 PAHs and alkylated PAH distributions by GC-MS and BPCA analyses by LC-TOF-MS. PAH concentrations (∑59 PAHs) of all soils ranged from 60 to 140 mg/kg, except one soil showing 559 mg/kg. The PAH source in the urban soils containing tailings was identified as petrogenic carbon due to (1) the dominance of low molecular weight PAHs, (2) bell shape distribution patterns of the alkylated PAHs, and (3) comparable BPCA distribution patterns to bituminous coals. In contrast, the PAH source of the ash-containing soil was identified as pyrogenic carbon by high molecular weight PAH percentages >80%, slope shape distribution patterns of the alkylated PAHs and a higher degree of aromatic condensation (B6CA/BPCA) than bituminous coals, coal ashes or charcoal. The urban soils containing different anthropogenic substrates revealed the occurrence of both a petrogenic and a pyrogenic PAH source. Surprisingly, the separate analyses of isolated coal ash particles revealed typical petrogenic indicators showing that by visual approach coal ashes cannot generally be classified as being of a pyrogenic PAH source.
- CO2 capture and storage: A way forward for sustainable environment. [Journal Article]
- JEJ Environ Manage 2018 Aug 13; 226:131-144
- The quest for a sustainable environment and combating global warming, carbon capture, and storage (CCS) has become the primary resort. A complete shift from non-renewable resources to renewable resou...
The quest for a sustainable environment and combating global warming, carbon capture, and storage (CCS) has become the primary resort. A complete shift from non-renewable resources to renewable resources is currently impossible due to its major share in energy generation; making CCS an imperative need of the time. This study, therefore, aims to examine the reckoning of carbon dioxide (CO2), measurement methods, and its efficient capture and storage technologies with an ambition to combat global warming and achieve environmental sustainability. Conventionally, physical, geological and biological proxies are used to measure CO2. The recent methods for CO2 analyses are spectrometry, electrochemical gas sensors, and gas chromatography. Various procedures such as pre, post, and oxyfuel combustion, and use of algae, biochar, and charcoal are the promising ways for CO2 sequestration. However, the efficient implementation of CCS lies in the application of nanotechnology that, in the future, could provide a better condition for the environment and economic outlooks. The captured carbon can be stored in the earth crust for trillions of years, but its leakage during storage can raise many issues including its emissions in the atmosphere and soil acidification. Therefore, global and collective efforts are required to explore, optimize and implement new techniques for CCS to achieve high environmental sustainability and combat the issues of global warming.
- Liquified Petroleum Gas (LPG) Supply and Demand for Cooking in Northern Ghana. [Journal Article]
- EEcohealth 2018 Aug 14
- Like many other countries, Ghana relies on biomass (mainly wood and charcoal) for most of its cooking needs. A national action plan aims to expand liquefied petroleum gas (LPG) access to 50% of the c...
Like many other countries, Ghana relies on biomass (mainly wood and charcoal) for most of its cooking needs. A national action plan aims to expand liquefied petroleum gas (LPG) access to 50% of the country's population by 2020. While the country's southern urban areas have made progress toward this goal, LPG use for cooking remains low in the north. The aim of this cross-sectional study was to characterize the current state of the LPG market in this area and examine opportunities and barriers to scale up LPG adoption. We interviewed 16 LPG suppliers (stove, cylinder, and fuel vendors) as well as 592 households in the Kassena-Nankana Districts (KND) of Ghana. We find large rural-urban differences in LPG uptake: less than 10% of rural households own LPG stoves compared with over half of urban households. Awareness of LPG is high across the region, but accessibility of fuel supply is highly limited, with just one refilling station located in the KND. Affordability is perceived as the main barrier to LPG adoption, and acceptability is also limited by widespread concerns about the safety of cooking with LPG. Transitioning to a cylinder recirculation model, and providing more targeted subsidies and credit options, should be explored to expand access to cleaner cooking in this region.
- Lake sediment fecal and biomass burning biomarkers provide direct evidence for prehistoric human-lit fires in New Zealand. [Journal Article]
- SRSci Rep 2018 Aug 14; 8(1):12113
- Deforestation associated with the initial settlement of New Zealand is a dramatic example of how humans can alter landscapes through fire. However, evidence linking early human presence and land-cove...
Deforestation associated with the initial settlement of New Zealand is a dramatic example of how humans can alter landscapes through fire. However, evidence linking early human presence and land-cover change is inferential in most continental sites. We employed a multi-proxy approach to reconstruct anthropogenic land use in New Zealand's South Island over the last millennium using fecal and plant sterols as indicators of human activity and monosaccharide anhydrides, polycyclic aromatic hydrocarbons, charcoal and pollen as tracers of fire and vegetation change in lake-sediment cores. Our data provide a direct record of local human presence in Lake Kirkpatrick and Lake Diamond watersheds at the time of deforestation and a new and stronger case of human agency linked with forest clearance. The first detection of human presence matches charcoal and biomarker evidence for initial burning at c. AD 1350. Sterols decreased shortly after to values suggesting the sporadic presence of people and then rose to unprecedented levels after the European settlement. Our results confirm that initial human arrival in New Zealand was associated with brief and intense burning activities. Testing our approach in a context of well-established fire history provides a new tool for understanding cause-effect relationships in more complex continental reconstructions.
- Activated carbon added to recycled paperboard to prevent migration into food: approach for determining efficacy, and first results. [Journal Article]
- FAFood Addit Contam Part A Chem Anal Control Expo Risk Assess 2018 Aug 14; :1-13
- Catcherboard MB12® from Smurfit Kappa is a recycled paperboard incorporating activated carbon to reduce the release of contaminants into food. An approach is proposed to determine the efficacy of the...
Catcherboard MB12® from Smurfit Kappa is a recycled paperboard incorporating activated carbon to reduce the release of contaminants into food. An approach is proposed to determine the efficacy of the activated carbon. Sorption into activated carbon increases the concentration ratio paperboard/food (distribution coefficient) and reduces the migration rate, i.e. prolongs the time for equilibration. Using silicone paper as food simulant, the concentration ratio was increased by a factor of at least 1000 compared to recycled paperboard without activated carbon, which is sufficient to meet the 1% criterion proposed for barriers. Sorbents have limited capacity. A load with in total 4000 mg surrogate substances/kg paperboard (in addition to the material from the paperboard) exceeded the capacity: concentration ratios were reduced and the release of paperboard constituents increased. Capacity is consumed by constituents from the printing inks and the packed food. Total amounts of substances in dry foods of sufficient volatility to potentially migrate into the paperboard through the gas phase at ambient temperature were determined by GC-FID. For the large majority of the dry foods, these amounts were clearly below the capacity limit even under the exaggerated assumption of total transfer. Migration of mineral oil hydrocarbons into cat food over up to 1 year was not detectable at 1 mg/kg. It is concluded that recycled paperboard with activated carbon is promising for respecting the 1% criterion stipulated for functional barriers to avoid food contamination from recycled paperboard.
- Investigation of Atrazine Sorption to Biochar With Titration Calorimetry and Flow-Through Analysis: Implications for Design of Pollution-Control Structures. [Journal Article]
- FCFront Chem 2018; 6:307
- Atrazine is one of the most common broad-leaf herbicides used in the world. However, due to extensive use for many years, atrazine often appears in surface and groundwater. Atrazine transport is inhi...
Atrazine is one of the most common broad-leaf herbicides used in the world. However, due to extensive use for many years, atrazine often appears in surface and groundwater. Atrazine transport is inhibited by degradation or sorption to soil components, especially organic matter. Biochar is a charcoal-like material produced from pyrolysis of biomass. Due to the amount and type of functional groups found on biochar, this product has shown potential for sorption of atrazine from solution. There is an interest in developing best management practices utilizing biochar to filter atrazine from non-point drainage with pollution-control structures such as blind inlets. The objective of this study was to explore the kinetics and thermodynamics of atrazine sorption to biochar using two different approaches: flow-through sorption cells and isothermal titration calorimetry (ITC). Twenty-five milligrams of an oak (Quercus spp.)-derived biochar was suspended in water and titrated 25 times (0.01 mL per titration) with atrazine at three different concentrations, and by a single titration (0.25 mL), with heat of reaction directly measured with ITC. A benchtop atrazine sorption study that simulated the titration experiment was also conducted. A continuous flow-through system was used to quantify the impact of contact time on atrazine sorption to biochar. Atrazine sorption to biochar displayed both exothermic and endothermic signals within each titration, although the net reaction was exothermic and proportional to the degree of sorption. Net enthalpy was -4,231 ± 130 kJ mole-1 atrazine sorbed. The existence of both exotherms and endotherms within a single titration, plus observation of an initial fast reaction phase from 0 to 300 s followed by a slower phase, suggested multiple sorption mechanisms to biochar. Results of flow-through tests supported kinetics observations, with the 300 s contact time removing much more atrazine compared to 45 s, while 600 s improved little compared to 300 s. Based on flow-through results, annual atrazine removal goal of 50%, and typical Midwestern U.S. tile drainage conditions, a pollution-control structure implementing this biochar sample would require 32 and 4 Mg for a design utilizing a contact time of 45 and 300 s, respectively. Future work is necessary for estimating degradation of atrazine sorbed to biochar.
- Home Is Where the Hearth Is: Anthracological and Microstratigraphic Analyses of Pleistocene and Holocene Combustion Features, Riwi Cave (Kimberley, Western Australia). [Journal Article]
- JAJ Archaeol Method Theory 2018; 25(3):739-776
- The manipulation of fire is a technological act. The identification of the archaeological signatures of the controlled use of fire has important implications not only for the estimations of the origi...
The manipulation of fire is a technological act. The identification of the archaeological signatures of the controlled use of fire has important implications not only for the estimations of the origins and functions of the first fireplaces but also for our understanding of prehistoric technological development and resource use. At Riwi (Kimberley region, Western Australia), excavations over two field seasons have revealed a discontinuous occupation sequence over the past 45 ka, showing numerous, different combustion features interspersed within the deposit. Anthracological and micromorphological investigations at Riwi Cave indicate that the combustion features at the site can be categorised into three types: flat combustion features (type A), dug combustion features (type B) and thick accumulations of mixed combustion residues (type C). These provide evidence for two kinds of combustion practice: (i) fires lit directly on the ground and most likely not re-used and (ii) ground ovens, the latter appearing some 10,000 years after the first evidence for occupation of the site. A comparison of the wood species identified within these combustion features with those from equivalent scattered context levels, enables an exploration of the potential factors influencing wood selection and fire use through time at the site. A detailed understanding of the relationship between wood charcoal remains and archaeological context yields significant information on changes to environmental context and site occupation patterns over time.
- Sorption of organic compounds to two diesel soot black carbons in water evaluated by liquid chromatography and polyparameter linear solvation energy relationship. [Journal Article]
- WRWater Res 2018 Jul 27; 144:709-718
- Substantial variability in sorption capacity of black carbon (BC) has been a major challenge for accurate fate and risk assessment of organic pollutants in soils and sediments. 16 model organic sorba...
Substantial variability in sorption capacity of black carbon (BC) has been a major challenge for accurate fate and risk assessment of organic pollutants in soils and sediments. 16 model organic sorbates (logKOW = 0.38-4.21) encompassing diverse chemical functionalities were used to probe the sorption capacity of two diesel soot samples representative of graphitic BC (BC1, specific surface area (SSA) = 87 m2/g) and amorphous, oxygenated BC (BC2; SSA = 3.6 m2/g). The BC-water sorption coefficients (logKBC) of the model sorbates were determined using reversed-phase liquid chromatography (RP-LC) on soot-filled columns. It was found that mass-based logKBC's of BC1 (1.64-3.66 L/kgBC) exceeded those of BC2 (0.68-3.48 L/kgBC) consistently for all model sorbates. However, area-normalized logKBC's of BC2 were larger than those of BC1, suggesting that the overall sorption was more favored on the oxygenated sorbent per area basis. Linear solvation energy relationships (LSERs) for sorption onto BC1 and BC2 were found to be logKBC = (2.49 ± 0.65)E + (-2.71 ± 0.88)S + (1.17 ± 0.46)A + (2.52 ± 0.34)V and logKBC = (1.12 ± 0.39)E + (-1.68 ± 0.32)S + (-3.70 ± 0.57)B + (4.37 ± 0.38)V + (-1.51 ± 0.22), respectively. The LSERs indicated that sorption onto soot was generally enhanced with increasing non-specific van der Waals and decreasing cavitation cost (i.e., eE, sS, and vV terms). The logKBC difference between BC1 and BC2, ΔlogKBC, appeared to be correlated with the H-bonding capacity of the sorbates but not logKOW. Analysis of literature and experimental logKBC's revealed that logKBC and logSSA across different types of BC (i.e., soot, char, charcoal, activated carbon) were linearly correlated for benzene and toluene (r2 = 0.88-0.91). This work illustrates the utility of RP-LC in determining the sorption coefficients of high-capacity sorbents and suggests the possibility of a unified sorption model for the continuum of black carbon.
New Search Next
- Activated charcoal significantly improved the reliability of methods for quantitative analysis of endogenous substances in biological specimens: Glutathione and cysteine as cases. [Journal Article]
- JCJ Chromatogr B Analyt Technol Biomed Life Sci 2018 Aug 04; 1095:241-250
- When developing a quantitative assay for exogenous or endogenous compounds, guidelines for method validation normally recommend that the biological specimens should be prepared in corresponding authe...
When developing a quantitative assay for exogenous or endogenous compounds, guidelines for method validation normally recommend that the biological specimens should be prepared in corresponding authentic matrices, yet "analyte-free authentic matrices" is in general not available. It is generally known that GSH and CYS are endogenous compounds and present in both prokaryotes and eukaryotes. Herein, an efficient approach for the quantitative analysis of endogenous substances in biological specimens was developed, and glutathione (GSH) & cysteine (CYS) were chosen as model endogenous substances. Activated carbon (AC), a common adsorbent for the adsorption of environmental pollutants, was used to remove the endogenous GSH and CYS and prepare "GSH&CYS-free biological matrix". The endogenous GSH and CYS in mouse plasma, blood and liver homogenate were found can be almost removed via incubating with 100 mg of AC for 2 h. After optimizing the derivatization reagents, internal standard and analytical parameters, a reliable quantitative assay of GSH and CYS in mouse plasma, blood and liver homogenate was developed and validated on LC-ESI-MS/MS using corresponding AC-adsorbed mouse biological matrices. The validation results indicated that the developed method provided suitable accuracy, sensitivity, specificity and high throughput for the analysis of GSH and CYS. Finally, the developed LC-ESI-MS/MS assay was successfully applied to measure the concentrations of GSH and CYS in liver injury mice. The presently developed methodology could be widely applied in the quantitative analysis of endogenous compounds in various complex mixtures such as biological, herbal and environmental samples.