Evaluation of the atmospheric chloride deposition in the Danube hydrological zone of Bulgaria

2014 ◽  
Vol 72 (4) ◽  
pp. 1143-1154 ◽  
Author(s):  
Tatiana Orehova ◽  
Tanya Vasileva
Keyword(s):  
Hydrological Zone ◽  
Chloride Deposition

scholarly journals A new analysis of wind on chloride deposition for long-term aerosol chloride deposition monitoring with weekly sampling frequency

2019 ◽  
Vol 198 ◽  
pp. 46-54 ◽  
Author(s):  
Ngoc Duc Pham ◽  
Yukihisa Kuriyama ◽  
Naoya Kasai ◽  
Shinji Okazaki ◽  
Katsuyuki Suzuki ◽  
...  
Keyword(s):  
Sampling Frequency ◽  
Chloride Deposition ◽  
Deposition Monitoring

Assessment of effective infiltration in the deep arid vadose zone of the Negev, Israel

2020 ◽  
Author(s):  
Noa Balaban ◽  
Ravid Rosenzweig ◽  
Philip Stauffer ◽  
Ofra Klein-BenDavid ◽  
Avraham Dody ◽  
...  
Keyword(s):  
Water Content ◽  
Water Flow ◽  
Deposition Rate ◽  
Vadose Zone ◽  
Soil Texture ◽  
Water Infiltration ◽  
Annual Rainfall ◽  
Water Fluxes ◽  
Chloride Deposition ◽  
Chloride Concentrations

<p>The Israeli national site for radioactive waste is situated in the Yamin Plain, within the Negev desert. Estimation of  water recharge to the ~500 m deep vadose zone underlying the site  is crucial for assessing risks related to contaminants transport. However, estimation of water fluxes in deep arid vadose zones is a challenging task because of their small magnitude and the lack of a direct measurement technology. Studies conducted in a deep arid vadose zone in Nevada, USA point to complex transient flow dynamics, in which the direction of water flow in the top of the vadose zone is upward while in the rest of the section water flows downwards to the water table.    </p><p>            In this study we present a combination of techniques which are used to obtain an initial evaluation of the water dynamics in this environment. These techniques include direct and continuous measurements of water content at the upper 5.5 m of the vadose zone through a vadose zone monitoring system which contain FTDR water content sensors; profiles of water content, leachable chloride and soil texture; and numerical modeling.</p><p>            The monitoring of the upper 5.5 m of the vadose zone during the years 2014-2018 indicates that even after extreme rain events of ~ 50 mm (constituting more than a half of the annual rainfall) there is no water infiltration to the lower parts of the section. These results exemplified the need for an alternative method to detect low water fluxes that characterize this arid area. We therefore use an inverse modeling approach where numerical solutions of water movement in the vadose zone are fitted to measured profiles of chemical and physical parameters from two shallow boreholes in the Yamin Plain. The water content of both boreholes revealed an extremely dry environment, with low saturations and high pore-water chloride concentrations, above 15,000 mg/l, in certain depths. Peak chloride concentrations did not coincide in the two boreholes, raising the question whether these peaks are connected to water fluxes or to changes in soil texture, which can inhibit water infiltration.</p><p>             Numerical simulations were then used to solve water flow and solute transport. Input parameters, including chloride deposition rate, precipitation rate, and surface run-off fraction were varied to fit the measured chloride profiles. Results indicate very small water fluxes of less than 1 mm/yr in the bottom of the vadoze zone. The simulations also show that the mass of chloride in the profile is less than the one expected based on estimated chloride deposition rate and published records of paleo-rain. These results suggest either a delayed climate shift to dry conditions compared to previous estimates for the region (8000 yr BP), and/or a partial input of the 4 g/m<sup>2</sup>/yr of deposited chloride, possibly due to runoff.</p>

scholarly journals Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

2010 ◽  
Vol 14 (5) ◽  
pp. 801-813 ◽  
Author(s):  
H. Guan ◽  
A. J. Love ◽  
C. T. Simmons ◽  
O. Makhnin ◽  
A. S. Kayaalp
Keyword(s):  
Spatial Variability ◽  
Coastal Region ◽  
South Australia ◽  
Kriging Model ◽  
Hilly Area ◽  
Residual Kriging ◽  
Atmospheric Factors ◽  
Chloride Deposition ◽  
Average Uncertainty ◽  
Significant Factors

Abstract. Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB) method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this study is to construct a chloride deposition map in the Mount Lofty Ranges (MLR), a coastal hilly area of approximately 9000 km2 spatial extent in South Australia. We examined geographic (related to coastal distance), orographic, and atmospheric factors that may influence chloride deposition, using partial correlation and regression analyses. The results indicate that coastal distance, elevation, as well as terrain aspect and slope, appear to be significant factors controlling chloride deposition in the study area. Coastal distance accounts for 70% of spatial variability in bulk chloride deposition, with elevation, terrain aspect and slope an additional 15%. The results are incorporated into a de-trended residual kriging model (ASOADeK) to produce a 1 km×1 km resolution bulk chloride deposition and concentration maps. The average uncertainty of the deposition map is about 20–30% in the western MLR, and 40–50% in the eastern MLR. The maps will form a useful basis for examining catchment chloride balance for the CMB application in the study area.

Towards a more Realistic Experimental Protocol for the Study of Atmospheric Chloride-Induced Stress Corrosion Cracking in Intermediate Level Radioactive Waste Container Materials

2014 ◽  
Vol 1665 ◽  
pp. 225-230 ◽  
Author(s):  
A.B. Cook ◽  
B. Gu ◽  
S.B. Lyon ◽  
R.C. Newman ◽  
D.L. Engelberg
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Sea Salt ◽  
Induced Stress ◽  
Waste Container ◽  
Deposition Density ◽  
Average Crack ◽  
Intermediate Level Radioactive Waste ◽  
Chloride Deposition

ABSTRACTThe occurrence of Atmospheric chloride-Induced Stress Corrosion Cracking (AISCC) under wetted deposits of MgCl2 or sea-salt at 70°C has been investigated at various Relative Humidities (RH). The appearance of AISCC is a function of the environmental RH. At 33% RH (the deliquescence point of MgCl2), AISCC generated under MgCl2 or sea-salt deposits is of a similar appearance with regards to the number of cracks produced and average crack length. At 50% RH sea-salt seems to be more aggressive at least in terms of crack frequency. This observation may highlight the significance of carnallite (KMgCl3.6H2O) in promoting AISCC in types 304L and 316L stainless steels. The use of accelerated testing methods to validate apparent thresholds in chloride deposition density and other critical factors that influence the initiation and propagation of AISCC is briefly discussed.

scholarly journals Crystallization Behavior of Ammonium Chloride in High-Pressure Heat Exchanger of Hydrotreating Unit

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Jianwen Zhang ◽  
Fan Zhang ◽  
Yan Li ◽  
Yahui Zhao ◽  
Gang Sheng
Keyword(s):  
Mass Transfer ◽  
High Pressure ◽  
Heat Exchanger ◽  
Ammonium Chloride ◽  
Volume Fraction ◽  
Flow Direction ◽  
Corrosion Cracking ◽  
Inlet Temperature ◽  
Corrosion Failure ◽  
Chloride Deposition

In view of the corrosion failure of a high-pressure heat exchanger in a diesel hydrogenation unit, the formation mechanism of ammonium chloride in a multiphase flow system is investigated in this article. Numerical simulation is carried out by user defined function (UDF) on the process of adding source of mass transfer in computational fluid dynamics (CFD) solvers. The distribution characteristics of ammonium chloride are illustrated by the parameters including crystallization temperature of ammonium chloride, volume fraction of ammonium chloride, and mass transfer rates of NH3 and HCl, and the causes of corrosion cracking in the U-shaped bend of the heat exchanger are discussed. The results show that there is a great risk of ammonium chloride deposition in the heat exchanger from 4.5 m away from the outlet of the second pass. The crystallization area in the tube gradually expands from the wall to the center along the flow direction, and the crystallization rate is higher near the tube wall. The field sampling test results show that the corrosion cracking is hydrogen-induced cracking, which is due to the existence of large amount of hydrogen, high impacting force, excessive flow rate, and the risk of ammonium chloride particle erosion at the U-bend. In order to alleviate the corrosion of ammonium chloride deposition, some improvement measures are put forward, such as raising the inlet temperature of the tube side to 215 °C and increasing the water injection by 30%, which play an important role in decreasing the formation of ammonium chloride in the heat exchange system.

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