Effects of pH and Carbonate Concentration on Dissolution Rates of the Lead Corrosion Product PbO2

2010 ◽  
Vol 44 (3) ◽  
pp. 1093-1099 ◽  
Author(s):  
Yanjiao Xie ◽  
Yin Wang ◽  
Vidhi Singhal ◽  
Daniel E. Giammar
Keyword(s):  
Corrosion Product ◽  
Dissolution Rates ◽  
Carbonate Concentration ◽  
Lead Corrosion ◽  
Effects Of Ph

scholarly journals Comparison and Modeling of Aqueous Dissolution Rates of Various Uranium Oxides

1996 ◽  
Vol 465 ◽  
Author(s):  
S. A. Steward ◽  
E. T. Mones
Keyword(s):  
Dissolution Rate ◽  
Atmospheric Oxygen ◽  
Fold Increase ◽  
Stable Phase ◽  
Uranium Oxides ◽  
Spent Fuel ◽  
Geologic Repository ◽  
Dissolution Rates ◽  
Intrinsic Dissolution ◽  
Carbonate Concentration

ABSTRACTThe purpose of this work has been to measure and model the intrinsic dissolution rates of uranium oxides under a variety of well-controlled conditions that are relevant to a geologic repository. When exposed to air at elevated temperature, spent fuel may form the stable phase U3O8. Dehydrated schoepite, UO3H2O, has been shown to exist in drip tests on spent fuel.Equivalent sets of U3O8 and UO3H2 dissolution experiments allowed a systematic examination of the effects of temperature (25–75°C), pH (8–10) and carbonate (2–200×10−4 molar) concentrations at atmospheric oxygen conditions.Results indicate that UO3H2O has a much higher dissolution rate (at least ten-fold) than U3O8 under the same conditions. The intrinsic dissolution rate of unirradiated U3O8 is about twice that of UO2. Dissolution of both U3O8 and UO3.H2O shows a very high sensitivity to carbonate concentration. Present results show a 25 to 50-fold increase in room-temperature UO3H2O dissolution rates between the highest and lowest carbonate concentrations.As with the UO2 dissolution data the classical observed chemical kinetic rate law was used to model the U3O8 dissolution rate data. The pH did not have much effect on the models, in agreement with the earlier analysis of the UO2 and spent fuel dissolution data,. However, carbonate concentration, not temperature, had the strongest effect on the U3O8 dissolution rate. The U3O8 dissolution activation energy was about 6000 cal/mol, compared with 7300 and 8000 cal/mol for spent fuel and UO2 respectively.

Effects of pH value, chloride and sulfate concentrations on galvanic corrosion between lead and copper in drinking water

2016 ◽  
Vol 13 (4) ◽  
pp. 602 ◽  
Author(s):  
Ding-Quan Ng ◽  
Yi-Pin Lin
Keyword(s):  
Drinking Water ◽  
Distribution Systems ◽  
Lead Concentration ◽  
Ph Value ◽  
Galvanic Corrosion ◽  
Corrosion Products ◽  
Lead Contamination ◽  
Lead Corrosion ◽  
Effects Of Ph ◽  
Lead Release

Environmental context Galvanic corrosion has been recently reported as the main cause of lead contamination in drinking water in urban cities. Conditions that can deter or promote galvanic corrosion, however, are not well understood. Fundamental investigations exploring the mechanisms and processes involved in galvanic corrosion in drinking water could help to implement proper corrective measures to safeguard public health from lead contamination. Abstract This study investigates the effects of pH value, chloride and sulfate concentrations on galvanic corrosion between lead and copper in drinking water. We hypothesised that galvanic corrosion would occur immediately when a lead–copper couple is first formed and that the release of lead would be suppressed by the subsequent formation of lead corrosion products. Therefore, unlike previous long-term studies using harvested lead pipes, batch experiments employing high-purity lead and copper (99.9%) wires under stagnant and completely mixed conditions were conducted for a 7-day period to test our hypotheses. It was found that enhanced lead release was indeed observed after the lead–copper couple was formed and the lead profiles after 48h were strongly influenced by lead corrosion products formed in the system. Under stagnant conditions, reducing pH and increasing either chloride or sulfate concentrations promoted lead release, leading to the formation of lead corrosion products such as cerussite and hydrocerussite as experiments proceeded. The effect of chloride concentration on total lead concentration measured in the aqueous phase was similar to that of sulfate at the same molar concentration, showing that the chloride-to-sulfate mass ratio may not provide a good indication for total lead concentration in water. This study provides essential information on fundamental mechanisms and processes involved in galvanic corrosion in drinking water and may be used to explain related phenomena observed in real drinking-water distribution systems.

Impact of Chlorine Disinfectants on Dissolution of the Lead Corrosion Product PbO2

2010 ◽  
Vol 44 (18) ◽  
pp. 7082-7088 ◽  
Author(s):  
Yanjiao Xie ◽  
Yin Wang ◽  
Daniel E. Giammar
Keyword(s):  
Corrosion Product ◽  
Lead Corrosion

scholarly journals Oyster Shell Dissolution Rates in Estuarine Waters: Effects of pH and Shell Legacy

2011 ◽  
Vol 30 (3) ◽  
pp. 659-669 ◽  
Author(s):  
George G. Waldbusser ◽  
Ryan A. Steenson ◽  
Mark A. Green
Keyword(s):  
Oyster Shell ◽  
Dissolution Rates ◽  
Estuarine Waters ◽  
Effects Of Ph
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