Phosphorus Removal from Manure by Mechanical Separation using Salt and Polymers: Theoretical Simulations and Experimental Data

Abstract.Full-scale separation apparatuses were used to process mink and sow manure. Mink manure was pretreated with iron sulfate and polymer; pig manure was pretreated with only polymer. Testing was done to study how adding chemicals affected phosphorus removal. Chemical equilibrium simulations show that raw manure contains several minerals, i.e., struvite, calcium phosphate, and vivianite. The estimated mass of struvite fit well with the amount of magnesium measured in the solid material. The amount of calcium phosphate precipitation depended on the stability constant of the complexes of organic material and calcium ions, estimated at pK = 3.5–4. With polymer addition, it was possible to remove mineral-bound phosphorus but not organic-bound phosphorus and orthophosphate. With iron salt addition, it was possible to remove both phosphorus minerals and dissolved orthophosphate. The molar ratio between orthophosphate and iron ions in the precipitate was measured to be 2:3. These data fit well with the chemical equilibrium simulations, which predicted that vivianite would form when the iron ion concentration increased. The simulation also indicated that the amount of struvite decreased slightly with iron addition. Keywords: Coagulation, Flocculation, Solid-liquid separation, Vivianite, Wastewater.

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Synthesis of Amorphous Calcium Phosphate as a Starting Material for α-Tricalcium Phosphate

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.267.119 ◽

2017 ◽

Vol 267 ◽

pp. 119-123

Author(s):

Zilgma Irbe ◽

Armands Buss ◽

Dagnija Loca ◽

Lasma Malniece

Keyword(s):

Calcium Phosphate ◽

Sodium Hydroxide ◽

Tricalcium Phosphate ◽

Amorphous Calcium Phosphate ◽

Ion Concentration ◽

Bone Tissue Regeneration ◽

Content Increase ◽

Reactive Component ◽

Aqueous Synthesis ◽

The Stability

α-Tricalcium phosphate (α-TCP) is an important reactive component in calcium phosphate bone cements which are used for the bone tissue regeneration and augmentation. By thermally treating amorphous calcium phosphate (ACP) at relatively low temperatures (650–900 °C), it is possible to obtain sub-micrometre or nanosized α-TCP particles. In the current research, it is shown that the aqueous synthesis environment where ACP is precipitated has significant influence on the stability of ACP and the α-TCP content in the thermally treated products. During ACP synthesis pH must be kept basic. While it is possible to synthesize ACP if potassium hydroxide or sodium hydroxide is used to raise the pH of synthesis, ammonium ions also must be present in the solution to obtain α-TCP after thermal treatment of ACP. If sodium hydroxide is used, higher α-TCP content is obtained (compare 89 % and 66 %). Increase of Ca/P ratio stabilizes ACP and allows to obtain products with high α-TCP content. Increase of both calcium and phosphate ion concentration in the synthesis destabilizes ACP and reduces the amount of α-TCP in the product (twofold increase reduced α-TCP content from 89% to 2%).

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Atomic disruption beam theory

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v11i5.296 ◽

2016 ◽

pp. 3524-3528

Author(s):

Casey Ray McMahon

Keyword(s):

Neutron Beam ◽

Beam Theory ◽

Solid Material ◽

Material Matter ◽

Solid Matter ◽

Plasma Generation ◽

Resulting Effect ◽

Drilling Operations ◽

The Stability

In this paper, I discuss the theory behind the use of a dense, concentrated neutron particle-based beam. I look at the particle based physics behind such a beam, when it is focused against solid material matter. Although this idea is still only theoretical, it appears that such a beam may be capable of disrupting the stability of the atoms within solid matter- in some cases by passing great volumes of neutrons between the electron and nucleus thus effectively â€œshieldingâ€ the electron from the charge of the nucleus. In other cases, by disrupting the nucleus by firing neutrons into it, disrupting the nucleus and weakening its bond on electrons. In either case- the resulting effect would be a disruption of the atom, which in the case of material matter would cause said material matter to fail, which would appear to the observer as liquification with some plasma generation. Thus, a dense neutron particle based beam could be used to effectively liquefy material matter. Such a beam could bore through rock, metal, or even thick, military grade armour, like that used on tanks- causing such materials to rapidly liquefy. The denser and thicker the neutron beam, the more devastating the effect of the beam- thus the faster material matter will liquefy and the greater the area of liquification. Such a beam would have applications in Defence, mining and drilling operations.

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Pure hydroxyapatite synthesis originating from amorphous calcium carbonate

Scientific Reports ◽

10.1038/s41598-021-91064-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Michika Sawada ◽

Kandi Sridhar ◽

Yasuharu Kanda ◽

Shinya Yamanaka

Keyword(s):

Calcium Carbonate ◽

Calcium Phosphate ◽

Room Temperature ◽

Molar Ratio ◽

Final Phase ◽

Amorphous Calcium Carbonate ◽

Phosphate Compound ◽

Synthesis Strategy ◽

Phosphorylation Reaction ◽

Subsequent Calcination

AbstractWe report a synthesis strategy for pure hydroxyapatite (HAp) using an amorphous calcium carbonate (ACC) colloid as the starting source. Room-temperature phosphorylation and subsequent calcination produce pure HAp via intermediate amorphous calcium phosphate (ACP). The pre-calcined sample undergoes a competitive transformation from ACC to ACP and crystalline calcium carbonate. The water content, ACC concentration, Ca/P molar ratio, and pH during the phosphorylation reaction play crucial roles in the final phase of the crystalline phosphate compound. Pure HAp is formed after ACP is transformed from ACC at a low concentration (1 wt%) of ACC colloid (1.71 < Ca/P < 1.88), whereas Ca/P = 1.51 leads to pure β-tricalcium phosphate. The ACP phases are precursors for calcium phosphate compounds and may determine the final crystalline phase.

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Charge Transfer Complexes of Ketotifen with 2,3-Dichloro-5,6-dicyano-p-benzoquinone and 7,7,8,8-Tetracyanoquodimethane: Spectroscopic Characterization Studies

Molecules ◽

10.3390/molecules26072039 ◽

2021 ◽

Vol 26 (7) ◽

pp. 2039

Author(s):

Gamal A. E. Mostafa ◽

Ahmed Bakheit ◽

Najla AlMasoud ◽

Haitham AlRabiah

Keyword(s):

Charge Transfer ◽

Spectroscopic Characterization ◽

Molar Ratio ◽

Charge Transfer Complexes ◽

Physical Parameters ◽

Spectrophotometric Methods ◽

Theoretical Approaches ◽

The Stability ◽

Ct Complexes

The reactions of ketotifen fumarate (KT) with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as π acceptors to form charge transfer (CT) complexes were evaluated in this study. Experimental and theoretical approaches, including density function theory (DFT), were used to obtain the comprehensive, reliable, and accurate structure elucidation of the developed CT complexes. The CT complexes (KT-DDQ and KT-TCNQ) were monitored at 485 and 843 nm, respectively, and the calibration curve ranged from 10 to 100 ppm for KT-DDQ and 2.5 to 40 ppm for KT-TCNQ. The spectrophotometric methods were validated for the determination of KT, and the stability of the CT complexes was assessed by studying the corresponding spectroscopic physical parameters. The molar ratio of KT:DDQ and KT:TCNQ was estimated at 1:1 using Job’s method, which was compatible with the results obtained using the Benesi–Hildebrand equation. Using these complexes, the quantitative determination of KT in its dosage form was successful.

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EFFECT OF NONCLASSICAL POLARIZATION OF Na+ AND K+ ON THE STABILITY OF SOIL COLLOIDAL PARTICLES IN SUSPENSION

Surface Review and Letters ◽

10.1142/s0218625x18500191 ◽

2017 ◽

Vol 24 (07) ◽

pp. 1850019

Author(s):

DING WU-QUAN ◽

HE JIA-HONG ◽

WANG LEI ◽

LIU XIN-MIN ◽

LI HANG

Keyword(s):

Negative Pressure ◽

Colloidal Particles ◽

Ion Concentration ◽

Electrostatic Repulsion ◽

Adjacent Soil ◽

Net Pressure ◽

The Stability ◽

Two Stages ◽

Soil Colloids ◽

Total Average

The study of soil colloids is essential because the stability of soil colloidal particles are important processes of interest to researchers in environmental fields. The strong nonclassical polarization of the adsorbed cations (Na[Formula: see text] and K[Formula: see text] decreased the electric field and the electrostatic repulsion between adjacent colloidal particles. The decrease of the absolute values of surface potential was greater for K[Formula: see text] than for Na[Formula: see text]. The lower the concentration of Na[Formula: see text] and K[Formula: see text] in soil colloids, the greater the electrostatic repulsion between adjacent colloidal particles. The net pressure and the electrostatic repulsion was greater for Na[Formula: see text] than for K[Formula: see text] at the same ion concentration. For K[Formula: see text] and Na[Formula: see text] concentrations higher than 50[Formula: see text]mmol L[Formula: see text] or 100 mmol L[Formula: see text], there was a net negative (or attractive) pressure between two adjacent soil particles. The increasing total average aggregation (TAA) rate of soil colloids with increasing Na[Formula: see text] and K[Formula: see text] concentrations exhibited two stages: the growth rates of TAA increased rapidly at first and then increased slowly and eventually almost negligibly. The critical coagulation concentrations of soil colloids in Na[Formula: see text] and K[Formula: see text] were 91.6[Formula: see text]mmol L[Formula: see text] and 47.8[Formula: see text]mmol L[Formula: see text], respectively, and these were similar to the concentrations at the net negative pressure.

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The stability of Fe(III)-As(V) co-precipitate in the presence of ascorbic acid: Effect of pH and Fe/As molar ratio

Chemosphere ◽

10.1016/j.chemosphere.2018.11.142 ◽

2019 ◽

Vol 218 ◽

pp. 670-679 ◽

Cited By ~ 3

Author(s):

Zidan Yuan ◽

Guoqing Zhang ◽

Jinru Lin ◽

Xiangfeng Zeng ◽

Xu Ma ◽

...

Keyword(s):

Ascorbic Acid ◽

Molar Ratio ◽

Effect Of Ph ◽

Acid Effect ◽

The Stability

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Effects of phosphorus recovery requirements on Swedish sludge management

Water Science & Technology ◽

10.2166/wst.2002.0644 ◽

2002 ◽

Vol 46 (4-5) ◽

pp. 435-440 ◽

Cited By ~ 16

Author(s):

E. Levlin ◽

M. Löwén ◽

K. Stark ◽

B. Hultman

Keyword(s):

Phosphorus Removal ◽

Agricultural Land ◽

Treatment Plant ◽

Phosphorus Recovery ◽

Molar Ratio ◽

Toxic Substances ◽

Biological Phosphorus Removal ◽

Sludge Management ◽

Small Stream ◽

Sludge Disposal

Expected requirements of phosphorus recovery, restrictions on sludge disposal on landfill, and difficulties in obtaining consensus on sludge use on agricultural land has led to several development works in Sweden to change sludge management methods. Especially sludge fractionation has gained interest including following steps to recover products and separate transfer of toxic substances into a small stream. Commercial systems are offered based on technology by Cambi/KREPRO and BioCon and other companies and many other methods are under development. Iron salts are widely used in Sweden as precipitation agents for phosphorus removal and this technology has some disadvantages for phosphorus recovery compared with the use of biological phosphorus removal. The amount of chemicals needed for a KREPRO or a BioCon system was calculated for a treatment plant which has an addition of iron salt resulting in 1,900 mole Fe per tonne DS. The result was compared with the chemical consumption of recovery systems installed at plants with lower use of iron for precipitation. The chemical consumption in equivalents per tonne DS was found to be 5,000 + 6,000 * (molar ratio iron to phosphorus).

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Co-Amorphous Simvastatin-Nifedipine with Enhanced Solubility for Possible Use in Combination Therapy of Hypertension and Hypercholesterolemia

Molecules ◽

10.3390/molecules23092161 ◽

2018 ◽

Vol 23 (9) ◽

pp. 2161 ◽

Cited By ~ 6

Author(s):

Cecilia Martínez-Jiménez ◽

Jorge Cruz-Angeles ◽

Marcelo Videa ◽

Luz Martínez

Keyword(s):

Combination Therapy ◽

Amorphous State ◽

Active Pharmaceutical Ingredient ◽

Molar Ratio ◽

Amorphous System ◽

Enhanced Solubility ◽

Significant Area ◽

One Year ◽

The Stability ◽

Therapy Of Hypertension

The high index of simultaneous incidence of hypertension and hypercholesterolemia in the population of many countries demands the preparation of more efficient drugs. Therefore, there is a significant area of opportunity to provide as many alternatives as possible to treat these illnesses. Taking advantage of the solubility enhancement that can be achieved when an active pharmaceutical ingredient (API) is obtained and stabilized in its amorphous state, in the present work, new drug-drug co-amorphous formulations (Simvastatin SIM- Nifedipine NIF) with enhanced solubility and stability were prepared and characterized. Results show that the co-amorphous system (molar ratio 1:1) is more soluble than the pure commercial APIs studied separately. Aqueous dissolution profiles showed increments of solubility of 3.7 and 1.7 times for SIM and NIF, correspondingly, in the co-amorphous system. The new co-amorphous formulations, monitored in time, (molar fractions 0.3, 0.5 and 0.7 of SIM) remained stable in the amorphous state for more than one year when stored at room temperature and did not show any signs of crystallization when re-heating. Inspection on the remainder of a sample after six hours of dissolution showed no recrystallization, confirming the stability of co-amorphous system. The enhanced solubility of the co-amorphous formulations makes them promising for simultaneously targeting of hypertension and hypercholesterolemia through combination therapy.

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Injectable calcium phosphate and styrene–butadiene polymer-based root canal filling material

Asian Biomedicine ◽

10.2478/abm-2021-0003 ◽

2021 ◽

Vol 15 (1) ◽

pp. 19-26

Author(s):

Hala B. Kaka ◽

Raid F. Salman

Keyword(s):

Calcium Phosphate ◽

Root Canal ◽

Setting Time ◽

Molar Ratio ◽

Styrene Butadiene Rubber ◽

Filling Material ◽

Butadiene Rubber ◽

Root Canal Filling ◽

Phosphate Powder ◽

Styrene Butadiene

Abstract Background Three-dimensional obturation of the root canal system is mandatory for a successful root canal treatment. Using a filling material with optimal properties may enable the root canal to be sealed well and therefore obtain the desired obturation. Objective To develop a new injectable paste endodontic filling material using calcium phosphate powder and a styrene–butadiene emulsion polymer. Methods The powder phase comprised an equivalent molar ratio of tetracalcium phosphate, anhydrous dicalcium phosphate, bismuth oxide, and calcium chloride. The liquid phase comprised a styrene–butadiene rubber emulsion in distilled water. The powder and the liquid were mixed to achieve a paste consistency. The paste was subjected to various tests including flow, setting time, dimensional change, solubility, and radiopacity to indicate its suitability as a root canal filling material. All these tests were conducted according to the American National Standards Institute–American Dental Association for endodontic sealing materials. After passing these tests, the paste was submitted to an injectability test. Results The material showed acceptable flowability with 19.1 ± 1.3 min setting time and 0.61 ± 0.16% shrinkage after 30 days of storage. We found the highest solubility at 24 h (6.62 ± 0.58%), then the solubility decreased to 1.09 ± 0.08% within 3 days. The material was more radiopaque than a 3 mm step on an aluminum wedge. Furthermore, the material showed good injectability of 93.67 ± 1.80%. Conclusions The calcium phosphate powder in styrene–butadiene emulsion met basic requirements for a root canal filling material with promising properties.

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The chemical stability of mendipite, diaboleïte, chloroxiphite, and cumengéite, and their relationships to other secondary lead(II) minerals

Mineralogical Magazine ◽

10.1180/minmag.1980.043.331.13 ◽

1980 ◽

Vol 43 (331) ◽

pp. 901-904 ◽

Cited By ~ 15

Author(s):

D. Alun Humphreys ◽

John H. Thomas ◽

Peter A. Williams ◽

Robert F. Symes

Keyword(s):

Chloride Ion ◽

Stability Diagram ◽

Chloride Ions ◽

Ion Concentration ◽

Stability Field ◽

Cupric Ion ◽

Free Energy Of Formation ◽

High Concentrations ◽

The Stability ◽

Ph Range

SummaryThe chemical stabilities of mendipite, Pb3O2Cl2, diaboleïte, Pb2CuCl2(OH)4, chloroxiphite, Pb3CuCl2O2(OH)2, and cumengéite, Pb19Cu24Cl42 (OH)44, have been determined in aqueous solution at 298.2 K. Values of standard Gibbs free energy of formation, ΔGf°, for the four minerals are −740, −1160, −1129, and −15163±20 kJ mol−1 respectively. These values have been used to construct the stability diagram shown in fig. I which illustrates their relationships to each other and to the minerals cotunnite, PbCl2, paralaurionite, PbOHCl, and litharge, PbO. This diagram shows that mendipite occupies a large stability field and should readily form from cold, aqueous, mineralizing solutions containing variable amounts of lead and chloride ions, and over a broad pH range. The formation of paralaurionite and of cotunnite requires a considerable increase in chloride ion concentration, although paralaurionite can crystallize under much less extreme conditions than cotunnite. The encroachment of the copper minerals on to the stability fields of those mineral phases containing lead(II) only is significant even at very low relative activities of cupric ion. Chloroxiphite has a large stability field, and at given concentrations of cupric ion, diaboleïte is stable at relatively high aCl−. Cumengéite will only form at high concentrations of chloride ion.

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