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C Ribeiro, F B Scheufele, H J Alves, A D Kroumov, F R Espinoza-Quiñones, A N Módenes, C E Borba
No abstract text is available yet for this article.
February 16, 2018: Environmental Technology
Tai-Hsiang Huang, Yun-Jie Lai, Zeng-Yei Hseu
In situ stabilization of trace elements by adding cheap amendments is an emerging technology for large-scale soil remediation. Various amendments have been examined well in the literature, but related have focused predominantly on short-term laboratory scale incubation or pot experiments. This study applied dolomitic lime at 40 ton ha-1, oyster shell (OS) at 80 ton ha-1, and sugarcane bagasse compost (SC) at 60 ton ha-1 to a paddy field in Taiwan for two rice (Oryza sativa L.) cropping seasons. The aims of study were to gain an understanding of the bioavailable concentrations of Cr, Ni, Cu, and Zn in the amended soil and the metal uptake of rice for practical amendment use in field-scale remediation of contaminated soils...
January 31, 2018: Chemosphere
Xueru Guo, Rui Zuo, Li Meng, Jinsheng Wang, Yanguo Teng, Xin Liu, Minhua Chen
Globally, groundwater resources are being deteriorated by rapid social development. Thus, there is an urgent need to assess the combined impacts of natural and enhanced anthropogenic sources on groundwater chemistry. The aim of this study was to identify seasonal characteristics and spatial variations in anthropogenic and natural effects, to improve the understanding of major hydrogeochemical processes based on source apportionment. 34 groundwater points located in a riverside groundwater resource area in northeast China were sampled during the wet and dry seasons in 2015...
February 6, 2018: International Journal of Environmental Research and Public Health
Aung Zaw Oo, Shigeto Sudo, Hiroko Akiyama, Khin Thuzar Win, Akira Shibata, Akinori Yamamoto, Tomohito Sano, Yuhei Hirono
A laboratory study was conducted to study the effects of liming and different biochar amendments on N2O and CO2 emissions from acidic tea field soil. The first experiment was done with three different rates of N treatment; N 300 (300 kg N ha-1), N 600 (600 kg N ha-1) and N 900 (900 kg N ha-1) and four different rates of bamboo biochar amendment; 0%, 0.5%, 1% and 2% biochar. The second experiment was done with three different biochars at a rate of 2% (rice husk, sawdust, and bamboo) and a control and lime treatment (dolomite) and control at two moisture levels (50% and 90% water filled pore space (WFPS))...
2018: PloS One
Pawan Kumar Gaury, Narendra Kumar Meena, A K Mahajan
The present research is to study hydrochemistry and water quality of Rewalsar Lake during pre-monsoon, monsoon, and post-monsoon seasons. The Ca2+ and Na+ are observed as the dominant cations from pre- to post-monsoon season. On the other hand, HCO3- and Cl- are observed dominant anions during pre-monsoon and monsoon seasons, whereas HCO3- and SO42- during post-monsoon season. The comparison of alkaline earth metals with alkali metals and total cations (Tz+) has specified that the carbonate weathering is the dominant source of major ions in the water of lake...
January 17, 2018: Environmental Monitoring and Assessment
Muhammad Shaaban, Yupeng Wu, Muhammad Salman Khalid, Qi-An Peng, Xiangyu Xu, Lei Wu, Aneela Younas, Saqib Bashir, Yongliang Mo, Shan Lin, Muhammad Zafar-Ul-Hye, Muhammad Abid, Ronggui Hu
Several studies have been carried out to examine nitrous oxide (N2O) emissions from agricultural soils in the past. However, the emissions of N2O particularly during amelioration of acidic soils have been rarely studied. We carried out the present study using a rice-rapeseed rotation soil (pH 5.44) that was amended with dolomite (0, 1 and 2 g kg-1 soil) under 60% water filled pore space (WFPS) and flooding. N2O emissions and several soil properties (pH, NH4+N, NO3--N, and nosZ gene transcripts) were measured throughout the study...
January 11, 2018: Environmental Pollution
Mehmet Yesiltas
Synchrotron-based high spatial resolution hyperspectral infrared imaging technique provides thousands of infrared spectra with high resolution, thus allowing us to acquire detailed spatial maps of chemical molecular structures for many grains in short times. Utilizing this technique, thousands of infrared spectra were analyzed at once instead of inspecting each spectrum separately. Sutter's Mill meteorite is a unique carbonaceous type meteorite with highly heterogeneous chemical composition. Multiple grains from the Sutter's Mill meteorite have been studied using this technique and the presence of both hydrous and anhydrous silicate minerals have been observed...
January 6, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Maja Radziemska, Eugeniusz Koda, Ayla Bilgin, Mgdalena D Vaverková
The experiment was carried out in order to evaluate the effects of trace element immobilizing soil amendments, i.e., chalcedonite, dolomite, halloysite, and diatomite on the chemical characteristics of soil contaminated with Cr and the uptake of metals by plants. The study utilized analysis of variance (ANOVA), principal component analysis (PCA) and Factor Analysis (FA). The content of trace elements in plants, pseudo-total and extracted by 0.01 M CaCl₂, were determined using the method of spectrophotometry...
December 23, 2017: International Journal of Environmental Research and Public Health
Xianwei Song, Yang Gao, Sophie M Green, Jennifer A J Dungait, Tao Peng, Timothy A Quine, Bailian Xiong, Xuefa Wen, Nianpeng He
Karst topography covers more than 1/3 of the People's Republic of China in area. The porous, fissured, and soluble nature of the underlying karst bedrock (primarily dolomite and limestone) leads to the formation of underground drainage systems. Karst conduit networks dominate this system, and rainfall takes a crucial role on water cycle at China karst area. Nitrogen loss from the karst system is of particular concern, with regard to nutrient use efficiency as well as water quality, as much of the karst system, including steeply sloping terrain, is used for intensive agriculture...
December 2017: Ecology and Evolution
Guoqing Jian, Maura Puerto, Anna Wehowsky, Clarence Miller, George J Hirasaki, Sibani L Biswal
HYPOTHESIS: The adsorption of anionic surfactants onto positively charged carbonate minerals is typically high due to electrostatic interactions. By blending anionic surfactants with cationic or zwitterionic surfactants, which naturally form surfactant complexes, surfactant adsorption is expected to be influenced by a competition between surfactant complexes and surfactant-surface interactions. EXPERIMENTS: The adsorption behavior of surfactant blends known to form complexes was investigated...
November 14, 2017: Journal of Colloid and Interface Science
Władysław P Węglarz, Artur Krzyżak, Grzegorz Machowski, Michał Stefaniuk
Zero echo time magnetic resonance imaging (ZTE MRI) at 9.4T was used to assess the local distribution of water in dolomite rocks under different saturation conditions. The results were compared with the industry standard Single Point Imaging (SPI) at 0.6T. 3D maps of the local amount of water saturating heterogeneous rock were obtained from the imaging data, and correlated with the corresponding structural images from high resolution micro-CT (μCT). The method can be applicable in the investigation of spatial kinetics of water saturation processes in porous, heterogeneous rocks where imaging methods based on spin echo, such as RARE, have failed due to short T2, while SPI is often impractical due to its long acquisition time...
November 23, 2017: Magnetic Resonance Imaging
Michael M Tice, Kimbra Quezergue, Michael C Pope
As part of its biosignature detection package, the Mars 2020 rover will carry PIXL, the Planetary Instrument for X-ray Lithochemistry, a spatially resolved X-ray fluorescence (μXRF) spectrometer. Understanding the types of biosignatures detectable by μXRF and the rock types μXRF is most effective at analyzing is therefore an important goal in preparation for in situ Mars 2020 science and sample selection. We tested mesoscale chemical mapping for biosignature interpretation in microbialites. In particular, we used μXRF to identify spatial distributions and associations between various elements ("fluorescence microfacies") to infer the physical, biological, and chemical processes that produced the observed compositional distributions...
November 2017: Astrobiology
Xun Zhou, Xiaocui Wang, Jiajun Han, Qin Cao, Changlong Jiang, Juan Guo, Haiyan Zhou
Subsurface K-rich brines are important mineral resources for fertilizer production while the evolution of such brines is poorly documented. In the Sichuan Basin in southwest China, they are found mainly in the Middle and Lower Triassic marine carbonate aquifers. Total dissolved solids of the brines range from 176 to 378 g/L and K concentrations, from 1.9 to 53.3 g/L. We found that the brines are mainly of Cl-Na type, while Ba is absent in the brines. Comparison of the brine samples with both the trajectories of ions and the newly proposed trajectories of ion ratios of evaporated seawater suggests that the brines are enriched in Ca, Sr, Li, and I, depleted in SO4 and Mg, and neither enriched nor depleted in Cl and Na...
November 9, 2017: Ground Water
Ulrich Kelka, Manolis Veveakis, Daniel Koehn, Nicolas Beaudoin
Nature has a range of distinct mechanisms that cause initially heterogeneous systems to break their symmetry and form patterns. One of these patterns is zebra dolomite that is frequently hosting economically important base metal mineralization. A consistent generic model for the genesis of these periodically banded rocks is still lacking. In this contribution, we present for the first time a fully consistent mathematical model for the genesis of the pattern by coupling the reactive fluid-solid system with hydromechanics...
October 27, 2017: Scientific Reports
Almudena Rivadeneyra, Alejandro Gonzalez-Martinez, Gabriela R Portela, Daniel J Martin-Ramos, Jesús Gonzalez-Lopez, María A Rivadeneyra
The ability of Halomonas maura to bioprecipitate carbonate and sulphate crystals in solid media at different manganese concentrations has been demonstrated in this study for the first time. The precipitated minerals were studied by X-ray diffraction, scanning and transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The precipitated minerals were different based on the manganese concentration present in the medium and the incubation time. In the absence of manganese, H. maura formed pseudokutnahorite crystals; in the presence of manganese, the concentration in the culture medium determined the precipitation carbonates, such as rhodochrosite and dolomites...
November 2017: Extremophiles: Life Under Extreme Conditions
Mónica Blasco, María J Gimeno, Luis F Auqué
Geothermometrical calculations in low-medium temperature geothermal systems hosted in carbonate-evaporitic rocks are complicated because 1) some of the classical chemical geothermometers are, usually, inadequate (since they were developed for higher temperature systems with different mineral-water equilibria at depth) and 2) the chemical geothermometers calibrated for these systems (based on the Ca and Mg or SO4 and F contents) are not free of problems either. The case study of the Arnedillo thermal system, a carbonate-evaporitic system of low temperature, will be used to deal with these problems through the combination of several geothermometrical techniques (chemical and isotopic geothermometers and geochemical modelling)...
February 15, 2018: Science of the Total Environment
Róbert Szép, Elena Mateescu, Aurelia Cristina Nechifor, Ágnes Keresztesi
A study of precipitation chemistry was conducted for 11 years (01 January 2006-31 December 2016) in the Ciuc basin, Eastern Carpathians, Romania. The studied area is an enclosed basin, also called "the Carpathians cold pole." All collected samples were analyzed for major cations and anions. HCO3(-) concentrations were calculated based on the empirical relationship between pH and HCO3(-). The multiannual arithmetic mean of pH values was found to be 6.57. The lowest and highest pH values were measured in 2009 and 2013, being 6...
October 1, 2017: Environmental Science and Pollution Research International
Liang Chen, Chun Hui Zhou, Hao Zhang, Dong Shen Tong, Wei Hua Yu, Hui Min Yang, Mao Quan Chu
The capture and reuse of NH4(+) is an ideal solution to treat NH4(+)-containing wastewater. The capture and reuse process needs to be clean and cost-effective. Currently, however, there are many obstacles, particularly in the availability, cost, and recovery of the chemical sources required. Here, we demonstrate a clean and efficient method to capture and recycle NH4(+) by a dolomite-aided struvite precipitation process. Dolomite calcined carefully in CO2 atmosphere was used as a Mg source to react with PO4(3-) (KH2PO4) and NH4(+) in model wastewater (2000 mg L(-1) NH4(+))...
August 13, 2017: Chemosphere
Ruina Xu, Rong Li, Jin Ma, Di He, Peixue Jiang
Geological carbon sequestration (GCS) in deep saline aquifers is an effective means for storing carbon dioxide to address global climate change. As the time after injection increases, the safety of storage increases as the CO2 transforms from a separate phase to CO2(aq) and HCO3(-) by dissolution and then to carbonates by mineral dissolution. However, subsequent depressurization could lead to dissolved CO2(aq) escaping from the formation water and creating a new separate phase which may reduce the GCS system safety...
August 16, 2017: Accounts of Chemical Research
C Gasaway, M Mastalerz, F Krause, C Clarkson, C Debuhr
This paper explores the applicability of micro-FTIR mapping to study heterogeneity of organic matter-lean siltstones. Closely spaced samples of Late Devonian dolomitic siltstones of the Middle Bakken Member were analysed with micro-FTIR, powder X-ray diffraction, and scanning electron microscopy (SEM) to explore the distribution and chemical properties of organic matter (OM), muscovite/feldspar/clay group, carbonates, and quartz, and their influence on porosity and permeability of these rocks. Our results show that quartz is the dominant component of the samples, and the main mineralogical differences between the samples are reflected in the abundance of carbonate minerals...
August 10, 2017: Journal of Microscopy
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