Analog Computation of Forms of Uranium Presence in Aqueous Solution

2012 ◽  
Vol 463-464 ◽  
pp. 12-15
Author(s):  
Jie Hong Lei
Keyword(s):  
Aqueous Solution ◽  
Chemical Composition ◽  
Ph Value ◽  
Safety Evaluation ◽  
Chemical Components ◽  
Migration Behavior ◽  
Analog Computation ◽  
Geological Disposal ◽  
Geochemical Model ◽  
Uranium Migration

In geological disposal of radioactive wastes, the study of uranium migration is very important for the safety evaluation of the repository. The forms of chemical components of uranium presence in aqueous solution that directly affect its migration behavior provide a basis for analog computation of the element. This paper uses PHREEQC, the geochemical model, for analog computation of forms of uranium presence in two types of groundwater, and analyzes the morphologies of the main elements and the influencing factors. The results show that the morphology of uranium is mainly controlled by the characteristics of the chemical composition of groundwater, while the PH value also has a great impact on the forms of uranium presence.

Analog Computation of Forms of Americium Presence in Aqueous Solution

2012 ◽  
Vol 549 ◽  
pp. 500-503
Author(s):  
Jie Hong Lei
Keyword(s):  
Aqueous Solution ◽  
Chemical Composition ◽  
Influencing Factors ◽  
Ph Value ◽  
Safety Evaluation ◽  
Chemical Components ◽  
Migration Behavior ◽  
Analog Computation ◽  
Geological Disposal ◽  
Geochemical Model

In geological disposal of radioactive wastes, the study of Americium migration is very important for the safety evaluation of the repository. The forms of chemical components of Americium presence in aqueous solution that directly affect its migration behavior provide a basis for analog computation of the element. This paper uses PHREEQC, the geochemical model, for analog computation of forms of Americium presence in two types of groundwater, and analyzes the morphologies of the main elements and the influencing factors. The results show that the morphology of Americium is mainly controlled by the characteristics of the chemical composition of groundwater, while the PH value also has a great impact on the forms of Americium presence.

Analog Computation of Forms of Plutonium Presence in Aqueous Solution

2012 ◽  
Vol 610-613 ◽  
pp. 48-51
Author(s):  
Jie Hong Lei
Keyword(s):  
Aqueous Solution ◽  
Chemical Composition ◽  
Influencing Factors ◽  
Ph Value ◽  
Safety Evaluation ◽  
Chemical Components ◽  
Migration Behavior ◽  
Analog Computation ◽  
Geological Disposal ◽  
Geochemical Model

In geological disposal of radioactive wastes, the study of Plutonium migration is very important for the safety evaluation of the repository. The forms of chemical components of Plutonium presence in aqueous solution that directly affect its migration behavior provide a basis for analog computation of the element. This paper uses PHREEQC, the geochemical model, for analog computation of forms of Plutonium presence in two types of groundwater, and analyzes the morphologies of the main elements and the influencing factors. The results show that the morphology of Plutonium is mainly controlled by the characteristics of the chemical composition of groundwater, while the PH value also has a great impact on the forms of Plutonium presence.

scholarly journals Trace element mobility during CO2 storage: application of reactive transport modelling

2019 ◽  
Vol 98 ◽  
pp. 04007
Author(s):  
Dirk Kirste ◽  
Julie K. Pearce ◽  
Sue D. Golding ◽  
Grant K.W. Dawson
Keyword(s):  
Water Quality ◽  
Chemical Composition ◽  
Reactive Transport ◽  
Transport Model ◽  
Co2 Storage ◽  
Chemical Components ◽  
Transport Modelling ◽  
Geochemical Model ◽  
Trace Element Mobility ◽  
The Individual

The geologic storage of CO2 carries both physical and chemical risks to the environment. In order to reduce those risks, it is necessary to provide predictive capabilities for impacts so that strategies can be developed to monitor, identify and mitigate potential problems. One area of concern is related to water quality both in the reservoir and in overlying aquifers. In this study we report the critical steps required to develop chemically constrained reactive transport models (RTM) that can be used to address risk assessment associated with water quality. The data required to produce the RTM includes identifying the individual hydrostratigraphic units and defining the mineral and chemical composition to sufficient detail for the modelling. This includes detailed mineralogy, bulk chemical composition, reactive mineral phase chemical composition and the identification of the occurrence and mechanisms of mobilisation of any trace elements of interest. Once the required detail is achieved the next step involves conducting experiments to determine the evolution of water chemistry as reaction proceeds preferably under varying elevated CO2 fugacities with and without impurities. Geochemical modelling of the experiments is then used for characterising the reaction pathways of the different hydrostratigraphic units. The resultant geochemical model inputs can then be used to develop the chemical components of a reactive transport model.

scholarly journals The chemical composition of Lessonia berteroana (ex L. nigrescens) in kelp harvest management and open access areas near Coquimbo, Chile

2018 ◽  
Vol 46 (2) ◽  
pp. 258-267
Author(s):  
J.M. Alonso Vega ◽  
Pedro H. Toledo
Keyword(s):  
Resource Management ◽  
Chemical Composition ◽  
Open Access ◽  
Environmental Changes ◽  
Chemical Components ◽  
Optimal Harvesting ◽  
Harvest Management ◽  
Species Population ◽  
Pressure Indicators ◽  
Lessonia Berteroana

Lessonia berteroana (ex L. nigrescens) is kelp freely harvested from Open Access Areas (OAA), and to some extent controlled, from Management and Exploitation Areas for Benthic Resources (MEABR). Harvesting pressures can change population dynamics, mainly in OAAs. In particular, harvesting may alter the chemical components of plants. Therefore, the aim of this study was to determine the harvesting effects on the chemical composition of L. berteroana from MEABR and OAA sampled during different seasons (spring and fall) and at two sites (Talquilla and Lagunillas) near Coquimbo (30°S), Chile. The crude protein (13.5 ± 1.0%), total lipids (0.9 ± 0.2%), crude fiber (16.3 ± 1.6%), ash (30.1 ± 1.5%), and nitrogen-free extract (39.2 ± 2.0%) contents of L. berteroana were within reference values for Laminariales species. Population descriptors and chemical analyses showed that harvesting had local effects, rather than being affected by a resource management strategy (OAA vs MEABR). The seasonal anticipator nature of L. berteroana may explain the detected seasonality of it's chemical composition. Regarding functional morphological structures, chemical composition in the fronds was more variable than in the stipes and perennial holdfast, probably since leaves are ephemeral structures susceptible to environmental changes and that play a functional, rather than structural, role in kelp. In the context of Chilean kelp resource management, monitoring chemical composition is useful for determining optimal harvesting periods to local scale and for deciding when commercially valuable compounds, such as alginate, should be extracted. These data also complement harvesting pressure indicators based on L. berteroana demographic parameters.

scholarly journals Selenium in wastewater can be adsorbed by modified natural zeolite and reused in vegetable growth

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110198
Author(s):  
Xiao Zhang ◽  
Xinyuan Li ◽  
Zihao Jin ◽  
Sadam Hussain Tumrani ◽  
Xiaodong Ji
Keyword(s):  
Aqueous Solution ◽  
Ph Value ◽  
Soil Improvement ◽  
Pollutant Removal ◽  
Maximum Adsorption Capacity ◽  
Selenium Content ◽  
Water Release ◽  
Soil Release ◽  
Release Ratio ◽  
Water Pollutant

Modified natural zeolites (MNZ) are widely used in pollutant removal, but how to address these MNZ that have adsorbed pollutants must be considered. Selenium is an essential trace element for metabolism and is also a water pollutant. Selenium is adsorbed in the water by MNZ in this study first. Then the Brassica chinensis L. was planted in the soil which contains the MNZ loaded with selenium (MNZ-Se) to explore selenium uptake. MNZ-Se release tests in water and soil were also considered. The results showed the following: (1) The maximum adsorption capacity of MNZ for selenium is 46.90 mg/g. (2) Water release experiments of MNZ-Se showed that regardless of how the pH of the aqueous solution changes, the trend of the release of selenium from MNZ-Se in aqueous solution is not affected and first decreases before stabilizing. (3) Soil release experiments of MNZ-Se showed that the selenium content in the soil increased and reached the concentration in the standard of selenium-rich soil. Addition amount and soil pH value will affect the release ratio. The release ratio of MNZ-Se in the water was higher than that in the soil. (4) With an increase in the soil MNZ-Se content, the selenium content in the soil and B. c increases. Above all, MZN can be a good medium for water pollutant removal and soil improvement.

scholarly journals Removal of Phenol from Aqueous Solution Using Internal Microelectrolysis with Fe-Cu: Optimization and Application on Real Coking Wastewater

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 720
Author(s):  
Do Tra Huong ◽  
Nguyen Van Tu ◽  
Duong Thi Tu Anh ◽  
Nguyen Anh Tien ◽  
Tran Thi Kim Ngan ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Ph Value ◽  
Reaction Rate Constant ◽  
Phenol Concentration ◽  
Treated Wastewater ◽  
Coking Wastewater ◽  
X Ray ◽  
Chemical Plating ◽  
Internal Electrolysis ◽  
Phenol Decomposition

Fe-Cu materials were synthesized using the chemical plating method from Fe powder and CuSO4 5% solution and then characterized for surface morphology, composition and structure by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD), respectively. The as-synthesized Fe-Cu material was used for removal of phenol from aqueous solution by internal microelectrolysis. The internal electrolysis-induced phenol decomposition was then studied with respect to various parameters such as pH, time, Fe-Cu material weight, phenol concentration and shaking speed. The optimal phenol decomposition (92.7%) was achieved under the conditions of (1) a pH value of phenol solution of 3, (2) 12 h of shaking at the speed of 200 rpm, (3) Fe-Cu material weight of 10 g/L, (4) initial phenol concentration of 100.98 mg/L and (5) at room temperature (25 ± 0.5 °C). The degradation of phenol using Fe-Cu materials obeyed the second-order apparent kinetics equation with a reaction rate constant of k of 0.009 h−1L mg−1. The optimal process was then tested against real coking wastewater samples, resulting in treated wastewater with favorable water indicators. Current findings justify the use of Fe-Cu materials in practical internal electrolysis processes.

Adsorption Characteristics of Phenol in Aqueous Solution by Pinus massoniana Biochar

2013 ◽  
Vol 295-298 ◽  
pp. 1154-1160 ◽  
Author(s):  
Guo Zhi Deng ◽  
Xue Yuan Wang ◽  
Xian Yang Shi ◽  
Qian Qian Hong
Keyword(s):  
Aqueous Solution ◽  
Ph Value ◽  
Pinus Massoniana ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Adsorbent Dosage ◽  
Salt Ions ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The objective of this paper is to investigate the feasibility of phenol adsorption from aqueous solution by Pinus massoniana biochar. Adsorption conditions, including contact time, initial phenol concentration, adsorbent dosage, strength of salt ions and pH, have been investigated by batch experiments. Equilibrium can be reached in 24 h for phenol from 50 to 250 mg• L-1. The optimum pH value for this kind of biochar is 5.0. The amount of phenol adsorbed per unit decreases with the increase in adsorbent dosage. The existence of salt ions makes negligible influence on the equilibrium adsorption capacity. The experimental data is analyzed by the Freundlich and Langmuir isotherm models. Equilibrium data fits well to the Freundlich model. Adsorption kinetics models are deduced and the pseudo-second-order kinetic model provides a good correlation for the adsorbent process. The results show that the Pinus massoniana biochar can be utilized as an effective adsorption material for the removal of phenol from aqueous solution.

scholarly journals Effects of rhizosphere fungi on the chemical composition of fruits of the medicinal plant Cinnamomum migao endemic to southwestern China

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jingzhong Chen ◽  
Xiaolong Huang ◽  
Bingli Tong ◽  
Deng Wang ◽  
Jiming Liu ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Fungal Community ◽  
Small Population ◽  
Biologically Active ◽  
Fungal Communities ◽  
Chemical Components ◽  
Rhizosphere Fungi ◽  
Medicinal Value ◽  
Main Driver ◽  
Fungal Populations

Abstract Background This study examined how rhizosphere fungi influence the accumulation of chemical components in fruits of a small population species of Cinnamomum migao. Results Ascomycota and Basidiomycota were dominant in the rhizosphere fungal community of C. migao. Pestalotiopsis and Gibellulopsis were associated with α-Terpineol and sabinene content, and Gibellulopsis was associated with crude fat and carbohydrate content. There were significant differences in rhizosphere fungal populations between watersheds, and there was no obvious change between fruiting periods. Gibberella, Ilyonectria, Micropsalliota, and Geminibasidium promoted sabinene accumulation, and Clitocybula promoted α-Terpineol accumulation. Conclusion The climate-related differentiation of rhizosphere fungal communities in watershed areas is the main driver of the chemical composition of C. migao fruit. The control of the production of biologically active compounds by the rhizosphere fungal community provides new opportunities to increase the industrial and medicinal value of the fruit of C. migao.

Phthalate degradation by glow discharge plasma enhanced with pyrite in aqueous solution

2016 ◽  
Vol 74 (6) ◽  
pp. 1365-1375 ◽  
Author(s):  
Chensi Shen ◽  
Shaoshuai Wu ◽  
Hui Chen ◽  
Sadia Rashid ◽  
Yuezhong Wen
Keyword(s):  
Aqueous Solution ◽  
Energy Efficiency ◽  
Glow Discharge ◽  
Discharge Plasma ◽  
Ph Value ◽  
Glow Discharge Plasma ◽  
Methyl Tert Butyl Ether ◽  
Butyl Ether ◽  
Polymeric Compound ◽  
X Ray

In order to prevent health risk from potential exposures to phthalates, a glow discharge plasma (GDP) process was applied for phthalate degradation in aqueous solution. The results revealed that the phthalate derivatives 4-hydroxyphthalic acid, 4-methylphthalic acid and 4-tert-butylphthalic anhydride could be degraded efficiently in GDP process (498 V, 0.2 A) with high removal efficiencies of over 99% in 60 minutes. Additionally, pyrite as a promising heterogeneous iron source in the Fenton reaction was found to be favorable for GDP process. The phthalate degradation reaction could be significantly enhanced by the continuous formation of •OH and the inhibition of the quenching reaction in the pyrite Fenton system due to the constant dissolution of Fe(II) from pyrite surface. Meanwhile, the initial pH value showed little impact on the degradation of phthalates and the energy efficiency of GDP system for phthalate degradation ranged between 0.280 × 10−9 and 1.210 × 10−9 mol/J, which is similar to the GDP system with phenol, bisphenol A and methyl tert-butyl ether as the substrates. Further, the X-ray diffraction and scanning electron microscopy with energy dispersive X-ray spectroscopy analyses indicated that the pyrite was relatively stable in GDP system and there was no obvious polymeric compound formed on the catalyst surface. Overall, this GDP process offers high removal efficiency, simple technology, considerable energy efficiency and the applicability to salt-containing phthalate wastewater.

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