Mechanisms of releasing magnesium ions from a magnesium anode in an electrolysis reactor with struvite precipitation

Struvite precipitation is common in waste water systems containing high concentrations of dissolved orthophosphates, free and saline ammonia and magnesium ions, such as in anaerobic fermentation systems, often leading to severe fouling. It appears that a reduction of the partial pressure of CO2, ie. pCO2 is a trigger mechanism for struvite precipitation. An algorithm was developed, based on equilibrium chemistry, to quantitatively predict the struvite precipitation potential of the water in such a process. This was then extended, to predict the change in state together with precipitation potential due to chemical perturbations, particularly variations of pCO2. Experimental verification of the algorithms is presented.

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Observations of the Thermal Decomposition of Brucite

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100101980 ◽

1968 ◽

Vol 26 ◽

pp. 446-447

Author(s):

P. L. Burnett ◽

W. R. Mitchell ◽

C. L. Houck

Keyword(s):

Thermal Decomposition ◽

Magnesium Oxide ◽

Basal Plane ◽

Magnesium Ions ◽

A Value ◽

Reaction Proceeds

Natural Brucite (Mg(OH)2) decomposes on heating to form magnesium oxide (MgO) having its cubic ﹛110﹜ and ﹛111﹜ planes respectively parallel to the prism and basal planes of the hexagonal brucite lattice. Although the crystal-lographic relation between the parent brucite crystal and the resulting mag-nesium oxide crystallites is well known, the exact mechanism by which the reaction proceeds is still a matter of controversy. Goodman described the decomposition as an initial shrinkage in the brucite basal plane allowing magnesium ions to shift their original sites to the required magnesium oxide positions followed by a collapse of the planes along the original <0001> direction of the brucite crystal. He noted that the (110) diffraction spots of brucite immediately shifted to the positions required for the (220) reflections of magnesium oxide. Gordon observed separate diffraction spots for the (110) brucite and (220) magnesium oxide planes. The positions of the (110) and (100) brucite never changed but only diminished in intensity while the (220) planes of magnesium shifted from a value larger than the listed ASTM d spacing to the predicted value as the decomposition progressed.

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The Effect of Agents which Modify Platelet Behaviour and of Magnesium Ions on Thrombus Formation In Vivo

Thrombosis and Haemostasis ◽

10.1055/s-0038-1666898 ◽

1979 ◽

Vol 42 (02) ◽

pp. 603-610 ◽

Cited By ~ 59

Author(s):

J H Adams ◽

J R A Mitchell

Keyword(s):

Thrombus Formation ◽

Cerebral Arteries ◽

Magnesium Ions ◽

Body Formation ◽

Inflammatory Agent ◽

Platelet Thrombus ◽

Magnesium Salts ◽

Higher Doses ◽

Do So

SummaryThe ability of potential anti-thrombotic agents to modify platelet-thrombus formation in injured cerebral arteries in the rabbit was tested. Low doses of heparin were without effect, while higher doses produced variable suppression of white body formation but at the expense of bleeding. Aspirin did not inhibit white body formation but another non-steroid anti-inflammatory agent, flurbiprofen was able to do so, as was the anti-gout agent, sulphinpyrazone. Magnesium salts both topically and parenterally, suppressed thrombus formation and increased the concentration of ADP which was required to initiate thrombus production at minor injury sites.

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Effect of substitution on the mechanism of conductivity of ultra dispersed lithium - iron spinel, substituted with magnesium ions

Journal of Nano- and Electronic Physics ◽

10.21272/jnep.9(5).05018 ◽

2017 ◽

Vol 9 (5) ◽

pp. 05018-1-05018-6

Author(s):

B. K. Ostafiychuk ◽

◽

L. S. Kaykan ◽

J. S. Mazurenko ◽

B. Ya. Deputat ◽

...

Keyword(s):

Magnesium Ions

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Abiotic reduction of 2,4-dinitrotoluene in the presence of sulfide minerals under anoxic conditions

Water Science & Technology ◽

10.2166/wst.1996.0235 ◽

1996 ◽

Vol 34 (10) ◽

pp. 25-33 ◽

Cited By ~ 3

Author(s):

Cheng Jiayang ◽

Makram T. Suidan ◽

Albert D. Venosa

Keyword(s):

Electron Donor ◽

Chemical Reduction ◽

Sulfide Minerals ◽

Sulfide Concentration ◽

Magnesium Ions ◽

High Concentration ◽

Anoxic Conditions ◽

High Affinity ◽

Iron Nickel ◽

Abiotic Reduction

Abiotic reduction of 2,4-dinitrotoluene (DNT) in the presence of sulfide minerals has been investigated under anoxic conditions at 35°C. 2,4-DNT was abiotically reduced to 4-amino-2-nitrotoluene (4-A-2-NT) and 2-amino-4-nitrotoluene (2-A-4-NT) in the presence of high concentration of sulfide (0.84 mM). No abiotic reduction of 2,4-DNT was observed in the presence of low sulfide concentration (0.42 mM). The rate and the extent of the abiotic reduction of 2,4-DNT were increased with an increase in sulfide concentration. Sulfide served as an electron donor for the reduction of 2,4-DNT. The 2-nitro group was preferentially reduced, making the 2-A-4-NT:4-A-2-NT ratio in the final products 2:1. The addition of iron, nickel, and cobalt minerals significantly enhanced the abiotic reduction. The FeS, NiS, and CoS solids formed in the serum bottles catalyzed the reduction of 2,4-DNT preferentially to 4-A-2-NT. MnS and CuS solids also catalyzed the reduction of 2,4-DNT to 4-A-2-NT, but did not change the overall reduction of 2,4-DNT. However, the presence of calcium, zinc, and magnesium minerals impeded 2,4-DNT reduction. The calcium, zinc, and magnesium ions have a high affinity to sulfide, inactivating sulfide as an electron donor for the chemical reduction of 2,4-DNT.

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Chemical Control of Struvite Precipitation

Journal of Environmental Engineering ◽

10.1061/(asce)0733-9372(2003)129:5(419) ◽

2003 ◽

Vol 129 (5) ◽

pp. 419-426 ◽

Cited By ~ 33

Author(s):

James D. Doyle ◽

Kath Oldring ◽

John Churchley ◽

Colin Price ◽

Simon A. Parsons

Keyword(s):

Chemical Control ◽

Struvite Precipitation

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Effects of Adenosine Triphosphate and Magnesium Ions on the Fumarase Reaction

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)91895-8 ◽

1969 ◽

Vol 244 (4) ◽

pp. 1070-1075

Author(s):

P E Penner ◽

L H Cohen

Keyword(s):

Adenosine Triphosphate ◽

Magnesium Ions

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Morphogenesis and evolution mechanisms of bacterially-induced struvite

Scientific Reports ◽

10.1038/s41598-020-80718-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Tian-Lei Zhao ◽

Han Li ◽

Hao-Fan Jiang ◽

Qi-Zhi Yao ◽

Ying Huang ◽

...

Keyword(s):

Time Course ◽

Carboxyl Groups ◽

Precipitation Process ◽

Phosphate Content ◽

Biomimetic Mineralization ◽

Struvite Precipitation ◽

Growth Habits ◽

Two Stages ◽

Relevant Work ◽

Insight Into

AbstractBacteria are able to induce struvite precipitation, and modify struvite morphology, leading to the mineral with various growth habits. However, the relevant work involving the morphogenesis is limited, thereby obstructing our understanding of bacterially mediated struvite mineralization. Here, an actinomycete Microbacterium marinum sp. nov. H207 was chosen to study its effect on struvite morphology. A combination of bacterial mineralization and biomimetic mineralization techniques was adopted. The bacterial mineralization results showed that strain H207 could induce the formation of struvite with grouping structure (i.e., a small coffin-like crystal grown on a large trapezoid-like substrate crystal), and the overgrowth structure gradually disappeared, while the substrate crystal further evolved into coffin-like, and quadrangular tabular morphology with time. The biomimetic experiments with different organic components confirmed that the soluble macromolecules rich in electronegative carboxyl groups secreted by strain H207 dominate the formation of the struvite grouping. The time-course biomimetic experiments with supernatant testified that the increase in pH and NH4+ content promoted the evolution of crystal habits. Moreover, the evolution process of substrate crystal can be divided into two stages. At the first stage, the crystal grew along the crystallographic b axis. At the later stage, coupled dissolution–precipitation process occurred, and the crystals grew along the corners (i.e., [110] and [1-10] directions). In the case of dissolution, it was also found that the (00-1) face of substrate crystal preferentially dissolved, which results from the low initial phosphate content and high PO43− density on this face. As a result, present work can provide a deeper insight into bio-struvite mineralization.

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