scholarly journals Divalent heavy metals and uranyl cations incorporated in calcite change its dissolution process

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Xiaohang Zhang ◽  
Jianan Guo ◽  
Shijun Wu ◽  
Fanrong Chen ◽  
Yongqiang Yang
Keyword(s):  
Heavy Metals ◽  
Carbon Dioxide ◽  
Crystal Growth ◽  
High Capacity ◽  
High Reactivity ◽  
Dissolution Process ◽  
Dissolution Behavior ◽  
Secondary Minerals

Abstract Due to the high capacity of impurities in its structure, calcite is regarded as one of the most attractive minerals to trap heavy metals (HMs) and radionuclides via substitution during coprecipitation/crystal growth. As a high-reactivity mineral, calcite may release HMs via dissolution. However, the influence of the incorporated HMs and radionuclides in calcite on its dissolution is unclear. Herein, we reported the dissolution behavior of the synthesized calcite incorporated with cadmium (Cd), cobalt (Co), nickel (Ni), zinc (Zn), and uranium (U). Our findings indicated that the HMs and U in calcite could significantly change the dissolution process of calcite. The results demonstrated that the incorporated HMs and U had both inhibiting and enhancing effects on the solubility of calcite, depending on the type of metals and their content. Furthermore, secondary minerals such as smithsonite (ZnCO3), Co-poor aragonite, and U-rich calcite precipitated during dissolution. Thus, the incorporation of metals into calcite can control the behavior of HMs/uranium, calcite, and even carbon dioxide.

Thermodynamic Studies of Iron Carbonate Solubility in Aqueous Monoethylene Glycol Mixtures and CO2 Atmosphere

2016 ◽  
Vol 830 ◽  
pp. 134-138 ◽  
Author(s):  
Camila Senna Figueiredo ◽  
Jailton Ferreira do Nascimento ◽  
Rony Oliveira de Sant'ana ◽  
Deborah Cordeiro de Andrade ◽  
Zaniel Souto Dantas Procópio ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Natural Gas ◽  
High Capacity ◽  
Gas Production ◽  
Aqueous Mixtures ◽  
Iron Carbonate ◽  
Low Viscosity ◽  
Carbon Dioxide Atmosphere ◽  
Equilibrium Data ◽  
Monoethylene Glycol

Monoethylene glycol (MEG) is being widely applied as thermodynamic inhibitor to avoid formation of natural gas hydrates. High hydrophilicity, low toxicity, low viscosity, low solubility in liquid hydrocarbons and high capacity of dissolving salts are advantageous for the use of MEG in the natural gas production. In addition, MEG recovery can be easily achieved considering its low volatility in relation to water, which makes the process economical and environmentally feasible. The reuse of MEG is being theme of research and phase equilibrium data for the involved species are required. In this work, a experimental procedure to synthetize iron carbonate and, afterwards, determine its solubility in aqueous mixtures of MEG in the presence of carbon dioxide atmosphere have been developed. Furthermore, a series of solubility data has been measured. This work presents a worthy contribution to the description of iron carbonate aqueous solubilities in the presence of MEG and carbon dioxide, regarding the instability of the salt to respect of oxidation. Subsequently, the knowledge of the behavior of the iron carbonate solubilities is useful for the industrial unities of production of natural gas and recovery of MEG.

Amino functionalized zeolitic tetrazolate framework (ZTF) with high capacity for storage of carbon dioxide

2011 ◽  
Vol 47 (7) ◽  
pp. 2011-2013 ◽  
Author(s):  
Tamas Panda ◽  
Pradip Pachfule ◽  
Yifei Chen ◽  
Jianwen Jiang ◽  
Rahul Banerjee
Keyword(s):  
Carbon Dioxide ◽  
High Capacity

High capacity carbon dioxide adsorption by inexpensive covalent organic polymers

2012 ◽  
Vol 22 (17) ◽  
pp. 8431 ◽  
Author(s):  
Hasmukh A. Patel ◽  
Ferdi Karadas ◽  
Ali Canlier ◽  
Joonho Park ◽  
Erhan Deniz ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
High Capacity ◽  
Organic Polymers ◽  
Carbon Dioxide Adsorption

Organic and metallic pollutants in water treatment and natural wetlands: a review

2012 ◽  
Vol 65 (1) ◽  
pp. 76-99 ◽  
Author(s):  
K. Haarstad ◽  
H. J. Bavor ◽  
T. Mæhlum
Keyword(s):  
Heavy Metals ◽  
Aquatic Plants ◽  
Metal Uptake ◽  
High Capacity ◽  
Treatment Wetlands ◽  
The European Union ◽  
Toxic Heavy Metals ◽  
Limit Values ◽  
Fish Samples ◽  
Other Substances

A literature review shows that more than 500 compounds occur in wetlands, and also that wetlands are suitable for removing these compounds. There are, however, obvious pitfalls for treatment wetlands, the most important being the maintenance of the hydraulic capacity and the detention time. Treatment wetlands should have an adapted design to target specific compounds. Aquatic plants and soils are suitable for wastewater treatment with a high capacity of removing nutrients and other substances through uptake, sorption and microbiological degradation. The heavy metals Cd, Cu, Fe, Ni and Pb were found to exceed limit values. The studies revealed high values of phenol and SO4. No samples showed concentrations in sediments exceeding limit values, but fish samples showed concentrations of Hg exceeding the limit for fish sold in the European Union (EU). The main route of metal uptake in aquatic plants was through the roots in emergent and surface floating plants, whereas in submerged plants roots and leaves take part in removing heavy metals and nutrients. Submerged rooted plants have metal uptake potential from water as well as sediments, whereas rootless plants extracted metals rapidly only from water. Caution is needed about the use of SSF CWs (subsurface flow constructed wetlands) for the treatment of metal-contaminated industrial wastewater as metals are shifted to another environmental compartment, and stable redox conditions are required to ensure long-term efficiency. Mercury is one of the most toxic heavy metals and wetlands have been shown to be a source of methylmercury. Methyl Hg concentrations are typically approximately 15% of Hgt (total mercury). In wetlands polycyclic aromatic hydrocarbons (PAH), bisphenol A, BTEX, hydrocarbons including diesel range organics, glycol, dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCB), cyanide, benzene, chlorophenols and formaldehyde were found to exceed limit values. In sediments only PAH and PCB were found exceeding limit values. The pesticides found above limit values were atrazine, simazine, terbutylazine, metolachlor, mecoprop, endosulfan, chlorfenvinphos and diuron. There are few water quality limit values of these compounds, except for some well-known endocrine disrupters such as nonylphenol, phtalates, etc.

The volatilization of heavy metals during co-combustion of food waste and polyvinyl chloride in air and carbon dioxide/oxygen atmosphere

2017 ◽  
Vol 244 ◽  
pp. 1024-1030 ◽  
Author(s):  
Chuncheng Ke ◽  
Xiaoqian Ma ◽  
Yuting Tang ◽  
Weihua Zheng ◽  
Zhendong Wu
Keyword(s):  
Heavy Metals ◽  
Carbon Dioxide ◽  
Polyvinyl Chloride ◽  
Food Waste ◽  
Oxygen Atmosphere

scholarly journals The Impact of Changing Environmental Conditions on the Retention of Heavy Metals Adsorbed by Pine Bark

2017 ◽  
pp. 278-284
Author(s):  
Oleksandr Khokhotva
Keyword(s):  
Heavy Metals ◽  
Environmental Conditions ◽  
Metal Removal ◽  
High Capacity ◽  
Pine Bark ◽  
Urea Solution ◽  
Metal Leaching ◽  
Total Efficiency ◽  
Runoff Water ◽  
The Impact

Landfills are widely used for the disposal of households' and industrial waste. Liquid landfill effluents contain heavy metals, are toxic to humans and ecosystems and have to be efficiently treated. One treatment option that is becoming popular is the reactive filter technology. The total efficiency of metal removal by a filter media greatly depends not only on adsorption itself, but also on the metal leaching from the adsorbent. The last parameter, in turn, may be dependant on changing environmental conditions since filters are usually located on open air and flow of contaminated water (landfill leachate, runoff water) has the intermittent nature. A filter material may dry, become frozen or stay wet, depending on a season. Previously adsorbed metals can leach from an adsorbent at the next flash of water, coming to water treatment facilities. Among others, pine bark has shown a high capacity to adsorb heavy metals from landfill leachates. In this study, pine bark has been pre-treated with urea-solution in order to increase its stability and adsorption properties. Within leaching experiments using either non-treated or pre-treated bark samples no significant influence of the changing environmental conditions on the extent of metal leaching was observed, though in most cases, metal leaching from wet bark samples exposed to freezing was somewhat higher. Zn leaching was the highest and Cu leaching the lowest for both NTB and UTB samples. The metal leaching from non-treated bark was several-fold higher compared to urea-treated bark. Possible mechanisms of barkurea interactions and reasons for enhanced metals adsorption by urea-modified bark are discussed.

scholarly journals Assessment of carbon dioxide separation by amine solutions using electrolyte non-random two-liquid and Peng-Robinson models: Carbon dioxide absorption efficiency

2021 ◽  
Vol 2 (3) ◽  
Author(s):  
Arash Esmaeili ◽  
◽  
Zhibang Liu ◽  
Yang Xiang ◽  
Jimmy Yun ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Co2 Concentration ◽  
Liquid Hydrocarbon ◽  
Absorption Efficiency ◽  
High Reactivity ◽  
Proper Solution ◽  
Co2 Absorption ◽  
Carbon Dioxide Absorption ◽  
Operational Conditions ◽  
Wide Range

A high pressure carbon dioxide (CO2) absorption from a specific gas in a conventional column has been evaluated by the Aspen HYSYS simulator using a wide range of single absorbents and blended solutions to estimate the outlet CO2 concentration, absorption efficiency and CO2 loading to choose the most proper solution in terms of CO2 capture for environmental concerns. The property package (Acid Gas-Chemical Solvent) which is compatible with all applied solutions for the simulation in this study, estimates the properties based on an electrolyte non-random two-liquid (E- NRTL) model for electrolyte thermodynamics and Peng-Robinson equation of state for the vapor and liquid hydrocarbon phases. Among all the investigated single amines as well as blended solutions, piperazine (PZ) and the mixture of piperazine and monoethanolamine (MEA) have been found as the most effective absorbents respectively for CO2 absorption with high reactivity based on the simulated operational conditions.

scholarly journals Transport and accumulation of heavy metals in undisturbed soil columns

2013 ◽  
Vol 9 (3) ◽  
pp. 187-194
Keyword(s):  
Heavy Metals ◽  
Kola Peninsula ◽  
Forest Floor ◽  
High Capacity ◽  
Soil Columns ◽  
Undisturbed Soil ◽  
Podzolic Soils ◽  
Floor Layer

The podzolic soils of the Kola Peninsula, Russia, have in localised areas been highly contaminated with copper and nickel from smelting activities. Migration and retention of these metals were investigated in undisturbed soil columns irrigated with simulated background and polluted precipitation in order to study the temporal processes of retention and release within the soil. The mineral layers were strongly acidified by the contaminated precipitation. Forest floor layers demonstrated a high capacity to retain input Ni and Cu under all conditions. Mineral layers accumulated some Cu, but released Ni. In general, Ni leached through the soil faster than Cu. Since metals are strongly retained in the forest floor layer, even after reduction or cessation of inputs there may be a significant long–term risk of their leaching to deeper soil and groundwater. This risk cannot be ameliorated without remediative intervention.

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