Appraisal of gastropod shell as calcium ion source for phosphate removal and recovery in calcium phosphate minerals crystallization procedure

2013 ◽  
Vol 91 (5) ◽  
pp. 810-818 ◽  
Author(s):  
N.A. Oladoja ◽  
I.A. Ololade ◽  
A.O. Adesina ◽  
R.O.A. Adelagun ◽  
Y.M. Sani
Keyword(s):  
Calcium Phosphate ◽  
Calcium Ion ◽  
Ion Source ◽  
Phosphate Removal ◽  
Gastropod Shell ◽  
Crystallization Procedure ◽  
Removal And Recovery

scholarly journals Hydroxyapatite Precipitation and Accumulation in Granules and Its Effects on Activity and Stability of Partial Nitrifying Granules at Moderate and High Temperatures

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1710
Author(s):  
Yong-Qiang Liu ◽  
Simone Cinquepalmi
Keyword(s):  
High Temperature ◽  
Calcium Phosphate ◽  
Granular Sludge ◽  
Phosphate Removal ◽  
Ammonium Oxidation ◽  
Mineral Contents ◽  
Research Attention ◽  
Oxidation Rates ◽  
P Content ◽  
Removal And Recovery

Precipitation and accumulation of calcium phosphate in granular sludge has attracted research attention recently for phosphate removal and recovery from wastewater. This study investigated calcium phosphate accumulation from granulation stage to steady state by forming heterotrophic granules at different COD/N ratios at 21 and 32 °C, respectively, followed by the transformation of heterotrophic granules to partial nitrifying granules. It was found that mature granules accumulated around 60–80% minerals in granules, much higher than young granules with only around 30% ash contents. In addition, high temperature promoted co-precipitation of hydroxyapatite and calcite in granules with more calcite than hydroxyapatite and only 4.1% P content, while mainly hydroxyapatite was accumulated at the moderate temperature with 7.7% P content. The accumulation of minerals in granules at the high temperature with 75–80% ash content also led to the disintegration and instability of granules. Specific ammonium oxidation rates were reduced, as well, from day 58 to day 121 at both temperatures due to increased mineral contents. These results are meaningful to control or manipulate granular sludge for phosphorus removal and recovery by forming and accumulating hydroxyapatite in granules, as well as for the maintenance of microbial activities of granules.

scholarly journals Phosphate removal and recovery using immobilized phosphate binding proteins

2018 ◽  
Vol 1 ◽  
pp. 100003 ◽  
Author(s):  
Kaushik Venkiteshwaran ◽  
Nilisha Pokhrel ◽  
Faten Hussein ◽  
Edwin Antony ◽  
Brooke K. Mayer
Keyword(s):  
Binding Proteins ◽  
Phosphate Removal ◽  
Phosphate Binding ◽  
Removal And Recovery

scholarly journals Phosphate removal and recovery from water using nanocomposite of immobilized magnetite nanoparticles on cationic polymer

2016 ◽  
Vol 37 (16) ◽  
pp. 2099-2112 ◽  
Author(s):  
Ahmad Abo Markeb ◽  
Amanda Alonso ◽  
Antonio David Dorado ◽  
Antoni Sánchez ◽  
Xavier Font
Keyword(s):  
Magnetite Nanoparticles ◽  
Cationic Polymer ◽  
Phosphate Removal ◽  
Removal And Recovery

scholarly journals Performance and adsorption mechanism of a magnetic calcium silicate hydrate composite for phosphate removal and recovery

2018 ◽  
Vol 2017 (2) ◽  
pp. 578-591 ◽  
Author(s):  
Lihong Peng ◽  
Hongliang Dai ◽  
Yifeng Wu ◽  
Zheqin Dai ◽  
Xiang Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Magnetic Separation ◽  
Adsorption Kinetics ◽  
Calcium Silicate ◽  
Calcium Silicate Hydrate ◽  
Phosphate Removal ◽  
Separation Technique ◽  
Phosphate Adsorption ◽  
X Ray ◽  
Removal And Recovery

Abstract A novel magnetic calcium silicate hydrate composite (Fe3O4@CSH) was proposed for phosphorus (P) removal and recovery from a synthetic phosphate solution, facilitated by a magnetic separation technique. The Fe3O4@CSH material was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), powder Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), zeta-potential and magnetic curves. The chemical composition and structure of Fe3O4@CSH and the successful surface loading of hydroxyl functional groups were confirmed. Phosphate adsorption kinetics, isotherm, and thermodynamic experiments showed that adsorption reaches equilibrium at 24 h, with a maximum adsorption capacity of 55.84 mg P/g under optimized experimental conditions. Adsorption kinetics fitted well to the pseudo second-order model, and equilibrium data fit the Freundlich isotherm model. Thermodynamic analysis provided a positive value for ΔH° (129.84 KJ/mol) and confirmed that phosphate adsorption on these materials is endothermic. The P-laden Fe3O4@CSH materials could be rapidly separated from aqueous solution by a magnetic separation technique within 1 min. A removal rate of more than 60% was still obtained after eight adsorption/desorption cycles, demonstrating the excellent reusability of the particles. The results demonstrated that the Fe3O4@CSH materials had high P-adsorption efficiency and were reusable.

Model-based evaluation of struvite recovery from an in-line stripper in a BNR process (BCFS)

2006 ◽  
Vol 53 (3) ◽  
pp. 191-198 ◽  
Author(s):  
X.-D. Hao ◽  
M.C.M. van Loosdrecht
Keyword(s):  
Nutrient Removal ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Carbon Oxidation ◽  
P Efficiency ◽  
Effluent Quality ◽  
P Recovery ◽  
Struvite Precipitation ◽  
Removal And Recovery ◽  
P Removal

Phosphate removal and recovery can be combined in BNR processes. This may be realised by struvite precipitation from the supernatant of the sludge in anaerobic compartments. This can be beneficial for either improving bio-P removal effluent quality or lowering the influent COD/P ratio required for bio-P removal. For this reason, a patented BNR process, BCFS®, was developed and applied in The Netherlands. Several questions relating to P-recovery and behaviour of the system remain unclear and need to be ascertained. For this purpose, a modelling technique was employed in this study. With the help of a previous developed model describing carbon oxidation and nutrient removal, three cases were fully simulated. The simulations demonstrated that there was an optimal stripping flow rate and P-recovery would increase in costs and bio-P activity might be negatively affected due to decreased bio-P efficiency if this value was exceeded. The simulations indicated that the minimal CODbiod/P ratio required for the effluent standard (1 g P/m3) could be lowered from 20 to 10 with 36% of P-recovery. A simulation with dynamic inflow revealed that the dynamic influent loads affected slightly the anaerobic supernatant phosphate concentration but the effluent phosphate concentration would not be affected with regular P-recovery.

SURFACE MORPHOLOGIES ON THE ADDITION OF TiO2 TO CALCIUM PHOSPHATE BIO-GLASS

2007 ◽  
Vol 19 (06) ◽  
pp. 389-394
Author(s):  
Wen C. Say ◽  
Chin C. Yeh ◽  
Chih-Hwa Chen
Keyword(s):  
Titanium Dioxide ◽  
Calcium Phosphate ◽  
Calcium Ion ◽  
Calcium Pyrophosphate ◽  
Second Step ◽  
Crystalline Phases ◽  
Mixed Solutions ◽  
Surface Morphologies ◽  
Hydroxyapatite Formation

Titanium dioxide is added into calcium phosphate bio-glass (CPG) to have crystalline phases of titanium phosphoric ( TiP 2 O 7) and calcium phosphoric ( CaP 2 O 7) on its surfaces. The bio-glass synthesis with the addition of titanium dioxide herein is denoted as TCPG. To elucidate their surface morphologies, both specimens of CPG and TCPG were immersed in Hanks' solution for two days before soaking in the mixed solutions of ( NH 4)2 HPO 4 and Ca ( NO 3)2 at 70°. Crystalline layers of titanium phosphoric were observed on the surfaces of TCPG from immersing in Hanks' solution. After which calcium pyrophosphate appeared on the second step of soaking process from the calcium ion contained solutions. Due to the absence of crystalline phases on the surfaces of CPG specimen, it can be deduced that the addition of titania ( TiO 2) causes the hydroxyapatite formation on the surface of bio-glass.

Recovering phosphorus as struvite from the digested swine wastewater with bittern as a magnesium source

2011 ◽  
Vol 64 (2) ◽  
pp. 334-340 ◽  
Author(s):  
Zhi-Long Ye ◽  
Shao-Hua Chen ◽  
Min Lu ◽  
Jian-Wen Shi ◽  
Li-Feng Lin ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Low Cost ◽  
Phosphate Removal ◽  
Swine Wastewater ◽  
Nitrogen And Phosphorus ◽  
Balance Analysis ◽  
Struvite Precipitation ◽  
Mass Balance Analysis ◽  
Crystal Product ◽  
Magnesium Source

Recovering nitrogen and phosphorus through struvite (MgNH4PO4·6H2O) crystallization from swine wastewater has gained increasing interest. However, swine wastewater contains complex compositions, which may hinder the formation of struvite crystal and affect the purity of the precipitates by forming other insoluble minerals. In this work, experiments were carried out to evaluate struvite precipitation in the anaerobically digested swine wastewater, with dosing bittern as a low-cost magnesium source. Exceeded 90% phosphate removal and 23–29% ammonium reduction were obtained. FTIR, XRD and mass balance analysis were combined to analyze the species of precipitated minerals. Results showed that the precipitates were struvite, mixed with amorphous calcium phosphate (ACP) and brucite. The presence of Ca2+ diminished the percentage of struvite and gave rise to ACP formation. Controlling pH below 9.5 and bittern dosage above 1% (w/w) could inhibit ACP precipitation and harvest a highly pure struvite crystal product.

scholarly journals Removing and Recovering Phosphate from Poultry Wastewater Using Amorphous Ceramics

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Youhui Xie ◽  
Qin Li ◽  
Xianzhi Zhao ◽  
Yi Luo ◽  
Yangming Wang ◽  
...  
Keyword(s):  
Silica Fume ◽  
High Performance ◽  
Recovery Process ◽  
Phosphate Removal ◽  
Phosphate Content ◽  
Effective Technique ◽  
Poultry Wastewater ◽  
Removal And Recovery

A novel and effective technique for phosphate from poultry wastewater was developed using amorphous ceramics. Amorphous ceramics, which showed high performance for phosphate removal and recovery from poultry wastewater, were synthesized using unlimitedly available, inexpensive materials such as silica fume and lime. Dissolved phosphate in poultry wastewater can be deposited as a solid on the surface of amorphous ceramics. Phosphate content on the surface of amorphous ceramics could reach 14.20%. The phosphate removal and recovery process and mechanism was revealed by a series of characterizations, such as XRD, FESEM, BET, and so on. The present study demonstrated that amorphous ceramics have great potential as a novel, beneficial material for removing and recovering phosphate from poultry wastewater.

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