scholarly journals The Migration Law of Iron during the Process of Water Icing

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 441
Author(s):  
Yuanqing Tang ◽  
Yan Zhang ◽  
Wanli Zhao ◽  
Tongshuai Liu ◽  
Yucan Liu
Keyword(s):  
Iron Concentration ◽  
Water System ◽  
Freezing Temperature ◽  
Average Concentration ◽  
Initial Concentration ◽  
Before And After ◽  
Shallow Lakes And Ponds ◽  
Solid Liquid ◽  
Ice Water ◽  
Migration Law

In this study, we utilized simulated icing experiments to investigate the effect of icing thickness, freezing temperature and initial concentration on the migration of iron in the ice–water system during water icing. The distribution coefficient “K” (the ratio of the average concentration of iron in the ice to that in the under-ice water) was used to describe the effect. The results indicated that iron partitioned stronger to under-ice water than to ice during the process of water icing, resulting in the concentration of iron in ice–water system before and after freezing being expressed as: ice < pre-freezing water < under-ice water. K decreased with the increase in icing thickness, freezing temperature and initial concentration. The temperature change in the solution will change the solubility of the solvent, so we explained the migration of iron during the process of water icing from the perspective of solid–liquid equilibrium theory. Too high or too low iron concentration may inhibit the growth of algae, thus affecting the underwater ecological environment. We expect that our study will arouse researcher’s attention to the change in iron concentration in shallow lakes and ponds at high latitudes during the icebound period.

scholarly journals Research on the Migration of the Total Manganese during the Process of Water Icing

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1626 ◽  
Author(s):  
Yan Zhang ◽  
Yuanqing Tang ◽  
Aixin Yu ◽  
Wanli Zhao ◽  
Yucan Liu
Keyword(s):  
Lower Layer ◽  
Water System ◽  
Middle Layer ◽  
Freezing Temperature ◽  
Experimental Methods ◽  
Average Concentration ◽  
Laboratory Simulation ◽  
Ice Thickness ◽  
Ice Water ◽  
Migration Law

Our research focused on the migration law of the total manganese (TMn) during the process of water icing. We utilized two experimental methods: (1) natural icing and (2) simulated icing. While using laboratory simulation, we explored the effects of ice thickness, freezing temperature, and initial concentrations on the migration of TMn in the ice-water system. The distribution coefficient “K” (the ratio of the average concentration of TMn in the ice body to the average concentration of TMn in the under-ice water body) was used to characterize it. The results indicated that TMn continuously migrated from ice to under-ice water during the process of water icing. The concentration of TMn in the ice was the upper layer < middle layer < lower layer, and K decreases as the ice thickness, freezing temperature, and initial concentration increased. We explained the migration of TMn during the process of water icing from the perspective of crystallography. Our research can arouse other researcher’s attention towards the change of TMn concentration in lakes in high latitudes during the icebound period.

scholarly journals The migration law of magnesium ions during freezing and melting processes

2021 ◽  
Author(s):  
Zhang Yan ◽  
Liu Tongshuai ◽  
Tang Yuanqing ◽  
Zhao Wanli ◽  
Ren Fangyun ◽  
...  
Keyword(s):  
Water Layer ◽  
Melting Process ◽  
Freezing Temperature ◽  
Laboratory Simulation ◽  
Ice Thickness ◽  
Magnesium Ions ◽  
Initial Concentration ◽  
Ice Melt ◽  
Initial Ph ◽  
Migration Law

AbstractTo explore the migration law of magnesium ions (Mg2+) during freezing and melting processes, laboratory simulation experiments involving freezing and melting were carried out to investigate the influence of ice thickness, freezing temperature, initial concentration, and initial pH on the distribution of Mg2+ in the ice-water system. The distribution coefficient “K” (the ratio of the Mg2+ concentration in the ice layer to the Mg2+ concentration in the water layer under ice) was used to characterize the migration ability of Mg2+. The results showed that during the freezing process, the concentration distribution of Mg2+ in the ice and water two-phase system was as follows: ice layer < water before freezing < water layer under ice; in other words, it migrated from ice layer to the water layer under ice. “K” decreased with increasing ice thickness, freezing temperature, initial concentration, and initial pH; the higher the ice thickness, freezing temperature, initial concentration, and initial pH were, the higher the migration efficiency of Mg2+ into the water layer under ice was. During the melting process, Mg2+ was released in large amounts (50–60%) at the initial stage (0–25%) and in small amounts (25–100%) uniformly in the middle and later periods. According to the change of Mg2+ concentration in ice melt water, an exponential model was established to predict Mg2+ concentration in ice melt period. The migration law of Mg2+during the freezing and melting process was explained by using first principles.

scholarly journals Migration Law of Atrazine During Freezing of Water

2021 ◽  
Author(s):  
Yan Zhang ◽  
Wanli Zhao ◽  
Aixin Yu ◽  
Yucan Liu ◽  
Fangyun Ren ◽  
...  
Keyword(s):  
Distribution Coefficient ◽  
High Latitude ◽  
Freezing Temperature ◽  
Freezing Process ◽  
Ice Thickness ◽  
Migration Ability ◽  
Initial Concentration ◽  
Atrazine Concentration ◽  
Freezing Period ◽  
Migration Law

Abstract To explore the migration law of atrazine during the freezing process, an indoor simulated freezing experiment was carried out. The distribution coefficient (K) was used to characterize the migration ability of atrazine and explore the effects of freezing thickness, freezing temperature, and initial concentration on the migration of atrazine between ice and water. The research results showed that the concentration relationship between the ice and water phases was: ice < water before freezing < water under the ice. This indicates that atrazine migrated to the water under the ice during the freezing process in our experiment. The K value decreased as the ice thickness, freezing temperature, and initial concentration increased; thus, the greater the ice thickness, the higher the freezing temperature, the greater the initial atrazine concentration, and the greater the ability of atrazine to migrate to the water under the ice. This study provides a reference for managing natural waterbodies in high-latitude and high-altitude environments during the freezing period.

scholarly journals Subglacial hydrology and the formation of ice streams

2014 ◽  
Vol 470 (2161) ◽  
pp. 20130494 ◽  
Author(s):  
T. M Kyrke-Smith ◽  
R. F Katz ◽  
A. C Fowler
Keyword(s):  
Ice Sheet ◽  
Water System ◽  
Coupled Model ◽  
Water Film ◽  
Mass Conservation ◽  
Ice Streams ◽  
Base Level ◽  
Ice Sheet Dynamics ◽  
Ice Water ◽  
Subglacial Meltwater

Antarctic ice streams are associated with pressurized subglacial meltwater but the role this water plays in the dynamics of the streams is not known. To address this, we present a model of subglacial water flow below ice sheets, and particularly below ice streams. The base-level flow is fed by subglacial melting and is presumed to take the form of a rough-bedded film, in which the ice is supported by larger clasts, but there is a millimetric water film which submerges the smaller particles. A model for the film is given by two coupled partial differential equations, representing mass conservation of water and ice closure. We assume that there is no sediment transport and solve for water film depth and effective pressure. This is coupled to a vertically integrated, higher order model for ice-sheet dynamics. If there is a sufficiently small amount of meltwater produced (e.g. if ice flux is low), the distributed film and ice sheet are stable, whereas for larger amounts of melt the ice–water system can become unstable, and ice streams form spontaneously as a consequence. We show that this can be explained in terms of a multi-valued sliding law, which arises from a simplified, one-dimensional analysis of the coupled model.

Pressure Drop and Mass Transfer Studies in Liquid Fluidized Beds

2006 ◽  
Author(s):  
Bhagavatula Venkata Ramana Murthy
Keyword(s):  
Mass Transfer ◽  
Pressure Drop ◽  
Liquid Velocity ◽  
Water System ◽  
Solid Particles ◽  
Sugar Water ◽  
Minimum Fluidization Velocity ◽  
Liquid Systems ◽  
Mass Transfer Studies ◽  
Solid Liquid

Fluidized beds are widely used in industries for mixing solid particles with liquids as the solid is vigorously agitated by the liquid passing through the bed and the mixing of the solid ensures that there are practically no temperature gradients in the bed even with exothermic or endothermic reactions (Mixing and the segregation in a liquid fluidized of particles with different sizes and densities", The Canadian Journal of Chemical Engineering, 1988). The violent motion of the solid particles also gives high heat transfer rates to the wall or to cooling tubes immersed in the bed. Because of the fluidity of the solid particles, it is easy to pass solid from one vessel to another. In the present experimental work, the relative density between solid and liquid phases on pressure drop under fluidized condition has been studied using the solid-liquid systems namely, glass beads-water, glass beads-kerosene, plastic beads-kerosene and diamond sugar-kerosene. Pressure drop - liquid velocity and void fraction - liquid velocity relationships have been found for all the mentioned solid-liquid systems under fluidized condition and results have been noted. The effect of the nature of the fluid on the minimum fluidization velocity and the pressure drop has been studied. In addition to the pressure drop studies, mass transfer studies have also been conducted with diamond sugar-water system with and without fluidization and results have been obtained. In addition to these, comparison of bed voidage, pressure drop and minimum fluidization velocity between denser and lighter liquids have been studied and the results have been obtained. Also, the value of rate of mass transfer with fluidization is compared that without fluidization for diamond sugar-water system and the results have been obtained.

scholarly journals Efficient removal of arsenic from water by dielectrophoresis-assisted adsorption

2018 ◽  
Vol 19 (4) ◽  
pp. 1066-1072
Author(s):  
Q. H. Jin ◽  
C. Y. Cui ◽  
H. Y. Chen ◽  
Y. Wang ◽  
J. F. Geng ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Removal Efficiency ◽  
Solution Ph ◽  
Residual Concentration ◽  
Initial Concentration ◽  
Weight Percentage ◽  
Before And After ◽  
High Concentrations ◽  
Plant Ash ◽  
Adsorbent Dose

Abstract Adsorption (ADS) and dielectrophoresis (DEP) techniques were combined (ADS/DEP) to efficiently remove As(V) in industrial wastewater. Fly ash, activated carbon, corncob and plant ash were tested to determine the best adsorbent by their adsorption capacity. Plant ash showed the highest adsorption capacity compared with the others. Different parameters such as solution pH and adsorbent dose were explored. The maximum As(V) removal efficiency was 91.4% at the optimized conditions (pH 9.0, adsorbent dose 5 g/L) when the initial concentration of As(V) was 15 mg/L. With the ADS/DEP technique, the plant ash particles with adsorbed As(V) were trapped on the electrodes in a DEP device. The ADS/DEP process could increase the removal efficiency of As(V) to 94.7% at 14 V even when the initial concentration of As(V) was 15 mg/L. And the residual concentration of As(V) decreased to 0.34 mg/L after two series of the ADS/DEP process. The adsorbents before and after DEP were examined by scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analysis. After the DEP process, the weight percentage of As(V) on the adsorbent surface increased to 0.96% from 0.5%. The ADS/DEP process could be a new efficient way to remove arsenic pollutant at high concentrations.

scholarly journals Cost and financial sustainability of a household-based water treatment and storage intervention in Zambia

2007 ◽  
Vol 5 (3) ◽  
pp. 385-394 ◽  
Author(s):  
Anyana Banerjee ◽  
Deborah A. McFarland ◽  
Ritu Singh ◽  
Robert Quick
Keyword(s):  
Water Treatment ◽  
Water System ◽  
Financial Loss ◽  
Household Water Treatment ◽  
Safe Water ◽  
Start Up ◽  
Household Water ◽  
Before And After ◽  
Program Costs ◽  
And Behavior

Providing safe water to &gt;1 billion people in need is a major challenge. To address this need, the Safe Water System (SWS) - household water treatment with dilute bleach, safe water storage, and behavior change - has been implemented in &gt;20 countries. To assess the potential sustainability of the SWS, we analyzed costs in Zambia of “Clorin” brand product sold in bottles sufficient for a month of water treatment at a price of $0.09. We analyzed production, marketing, distribution, and overhead costs of Clorin before and after sales reached nationwide scale, and analyzed Clorin sales revenue. The average cost per bottle of Clorin production, marketing and distribution at start-up in 1999 was $1.88 but decreased by 82% to $0.33 in 2003, when &gt;1.7 million bottles were sold. The financial loss per bottle decreased from $1.72 in 1999 to $0.24 in 2003. Net program costs in 2003 were $428,984, or only $0.04 per person-month of protection. A sensitivity analysis showed that if the bottle price increased to $0.18, the project would be self-sustaining at maximum capacity. This analysis demonstrated that efficiencies in the SWS supply chain can be achieved through social marketing. Even with a subsidy, overall program costs per beneficiary are low.

Hydrogeochemical Mechanism of the Petroleum Hydrocarbon Pollution in Karst Fissure Groundwater System

2013 ◽  
Vol 295-298 ◽  
pp. 159-163 ◽  
Author(s):  
Zhen Min Ma ◽  
Yun Yun Luo ◽  
Yun Zhi Fang ◽  
Yu Song Hou
Keyword(s):  
Water Quality ◽  
Petroleum Hydrocarbons ◽  
Petroleum Hydrocarbon ◽  
Water System ◽  
Quality Parameters ◽  
Groundwater System ◽  
Hydrocarbon Pollution ◽  
Groundwater Environment ◽  
Before And After ◽  
Fissure Water

The research of hydrogeochemical mechanism of petroleum hydrocarbon in karst fissure groundwater system is important to predict the trend of petroleum hydrocarbons and the change of groundwater environment. We take the karst fissure water system as the research object, where there is a refinery. The variation of SO42-, HCO3-, NO3-, NO2-, HS- can be used as a hydrogeochemical sign of petroleum hydrocarbon pollution by analyzing the change of water quality parameters before and after karst fissure water contaminated by petroleum hydrocarbon. It has been also analyzed systematically that hydrogeochemical mechanism including desulfurization, denigration and ion exchange happen during the pollution process in the karst fissure water system. It is pointed out that the human activities have a great impact on the groundwater and changes of environment.

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