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Showing 1 to 20 of 126 for “"orthophosphate"”.
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Solubility and speciation of plutonium(VI) with orthophosphate
Pu(VI) speciation and solubility with phosphate was examined at pH from 0.3 to 12.2, Pu(VI) concentrations from 5 $\times\ {\rm 10}\sp{-5}$ M to 1.3 $\times\ {\rm 10}\sp{-3}$ M and phosphate concentrations up to 0.6 M. Absorption spectroscopy, solubility experiments, scanning electron microscopy …
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Examination of synergism in nitrate and orthophosphate removal in bioreactors
… study evaluated materials suitable to convert orthophosphate into a non-bioavailable form as well as examine the synergistic effects of using this material in conjunction with a woodchip bioreactor known to have a high affinity for nitrate-N removal. The evaluation of materials was conducted …
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Maximization of the Electrochemical Detection of Orthophosphate in Organic-Aqueous Solutions.
It is well known that phosphorus is an essential nutrient for the growth of organisms. Therefore, it plays an important role as a growth-limiting nutrient in natural waters. Phosphorus-stimulated proliferation of plant micro- and macroorganisms in natural waters accelerates eutrophication thereby …
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Investigation of calcium orthophosphate chemical effects in a post-LOCA nuclear reactor containment
Calcium leached from NUKON fiberglass in containment following a Loss of Coolant Accident (LOCA) could lead to the formation of chemical precipitates that in turn cause head-loss increase due to filtering through a fibrous debris accumulation at the sump pump screens. Experiments conducted on the …
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Corrosion in New Construction:Elevated Copper, Effects of Orthophosphate Inhibitors, and Flux Initiated Microbial Growth
… bench scale testing indicated that adding 2 mg/L orthophosphate corrosion inhibitor would effectively decrease copper to a level that would comply with the EPA's Copper Action Limit. Orthophosphate corrosion inhibitors are used by utilities to limit lead and copper corrosion from consumer's …
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Evaluation of Zinc Orthophosphate to Control Lead Solder Corrosion in Waters With High Chloride to Sulfate Mass Ratio
… but in this work a combination of zinc orthophosphate and moderate alkalinity mitigated lead release in testing at two utilities. Either zinc alone or phosphate alone were irrelatively ineffective, but the combination of zinc orthophosphate reduced lead leaching by 54-99% (compared to …
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Advancing Fundamental Understanding of Lead-Tin Solder Corrosion in Drinking Water: Nitrate Spallation Mechanism, Inhibition by Zinc Orthophosphate and Free Chlorine, and Implications for Canned Foods
… water is a source of lead contamination, 3) zinc orthophosphate offers superior corrosion control to mitigate nitrate attack, and 4) free chlorine can inhibit solder corrosion by electrochemical reversal. These principles were also applied to an exemplary related problem of lead contamination of …
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Evaluation of iron valence state alterations in thermally processed liquid model systems
… 24 ppm of iron as either ferrous sulfate, ferric orthophosphate or ferric orthophosphate + 110 ppm ascorbic acid was thermally processed as 240, 250 and 260°F for 3, 6, 9, 12 and 15 minutes. Levels of elemental, nonelemental, soluble, total ionic and ferrous iron were measured for the model …
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Investigation of Copper Pitting Propensity Using Bench and Field Scale Testing
… effectiveness of corrosion inhibitors including orthophosphate, an orthophosphate-polyphosphate blend, and zinc polyphosphate. Results suggested that zinc polyphosphate provided the greatest likelihood of mitigating copper pitting corrosion, whereas orthophosphate and the …
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The link between Permeable Interlocking Concrete Pavement (PICP) design and nutrient removal
… of various nutrients (ammonia-nitrogen, orthophosphate-phosphorus and nitrate-nitrogen) commonly found in stormwater runoff. Ten experimental cells each housing a different permeable pavement design were constructed in the NEB laboratory at the UCT. Infiltration tests (ASTM C1781) were …
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Addressing gaps in the US EPA Lead and Copper Rule: Developing guidance and improving citizen science tools to mitigate corrosion in public water systems and premise plumbing
… residents identify lead problems, 2) Refines orthophosphate corrosion control guidance to help reduce cuprosolvency, 3) Identifies challenges to mitigating cuprosolvency by raising pH, and 4) Develops guidance that can help residents assess and address cuprosolvency problems. Lead in drinking …
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The Evaluation of Permeable Cementitious Media for Nutrient Removal
… media for the removal of nitrate-nitrogen and orthophosphate-phosphorus. Batch reactor tests were used to determine nitrate and orthophosphate removal and retention for five permeable reactive concrete mixtures. Additionally, fixed-bed breakthrough experiments were used to determine the nitrate …
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The use of biofiltration cells to filter contaminated water flowing from a slum settlement in South Africa
… reductions of 98.51% of ammonia and 100% of orthophosphate concentrations. E. coli bacteria were also reduced by nearly 100%. Phytoremediation played a role in reducing contamination by removing 97.07%, 89.70% and 100% for ammonia, orthophosphate and E. coli respectively over the study period …
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Comparative examination of Lake Spokane groundwater for nutrient discharge by residential development influence
… for chloride, ammonium, nitrite plus nitrate and orthophosphate through the Washington Department of Ecology's Manchester Laboratory. Surface water samples and a subset of groundwater samples were analyzed for ammonium, nitrite plus nitrate and orthophosphate through Eastern Washington University. …
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Novel Insights into Lead Corrosion Control: Safely Changing Source Waters, Effective Use of Zinc Phosphate Inhibitors, Electrochemical Reversal of Solder, and Significance of Lead-Polyphosphate Complexation
… that in certain corrosive waters zinc orthophosphate can dramatically reduce lead contamination from solder at pHs around 7.5-9.5, but is ineffective in relatively non-corrosive waters or at pHs outside this range, 3) reveal that prolonged exposure to free chlorine can dramatically …
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GVWD corrosion control initiative, phase II: inhibitor chemical testing at Seymour Dam
… with chemical suppliers determined that zinc orthophosphate and Type N sodium silicate offered the best potential as corrosion inhibitors with GVWD type waters. Thus it was decided to evaluate (within the limitations that the seven loop pilot plant would allow) zinc orthophosphate, type N …
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Investigation of the mechanism of action of pep carboxylase
Phosphoenolpyruvate carboxylase (orthophosphate: oxaloacetic acid carboxylyase, E.C.4.1.2.31) was isolated from 4-day germinated peanut cotyledons and purified about 2400-fold. A large-scale purification procedure has been developed in order to obtain large quantities of the highly-purified enzyme. …
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Spatio-temporal characterization of a complete algal bloom event using fluorescence spectroscopy in tandem with conventional physico-chemical methods
… water quality parameters such as pH, turbidity, orthophosphate, total filtered nitrogen, and total filtered carbon were tracked, and the 3-D fluorescence EEM spectroscopy was analyzed. Water quality parameters confirmed bloom development and proliferation through an observed logarithmic change in …
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Effects of water chemistry, temperature, gaseous cavitation & phosphate inhibitors on concrete corrosion
… scaling. At low alkalinity the addition of zinc orthophosphate or polyphosphate reduced corrosion of concrete. The addition of orthophosphate under low alkalinity conditions increased aluminum leaching and could push aluminum concentrations above the EPA SMCL threshold. At high alkalinity …
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Non-Uniform Copper Corrosion in Potable Water: Theory and Practice
… loss, pit density and/or maximum depth. Zinc orthophosphate had the largest positive impact on electrochemical measures of pitting. However, experimental studies suggested that if zinc orthophosphate was dosed to a system for a period of time, and dosing was then stopped, very serious pitting …
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