Development of Artificial Seed Crystal for Crystallization of Calcium Phosphate

Moriyama, Katsumi; Kojima, Toshihiro; Minawa, Y.; Matsumoto, S.; Nakamachi, Kazuo

doi:10.1080/09593330.2001.9619163

Cited by 66 publications

(24 citation statements)

References 5 publications

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“…The factors that affect the phosphorus recovery ratio include chemical factors, such as reaction pH, added magnesium/phosphate-phosphorus (Mg/PO 4 -P) ratio, ammonium-nitrogen/phosphate-phosphorus (NH 4 -N/PO 4 -P) ratio, supersaturation degree, and phosphorus volumetric loading, and physical factors relating to the crystal properties, such as crystal particle size, crystal surface areas, and fluidized conditions (Doyle and Parssons, 2002;Durrant et al, 1999;Hirasawa et al, 2002;Moriyama et al, 2001;Ohlinger et al, 1998;Stratful et al, 2004). Moreover, at some concentrations of suspended solids in the raw water, fine MAP particles are entrained by the suspended solids and flow out with the treated water, causing the recovery ratio to be decreased, in some cases.…”

Section: Experimental Methodsmentioning

confidence: 99%

Use of a Seeder Reactor to Manage Crystal Growth in the Fluidized Bed Reactor for Phosphorus Recovery

Shimamura¹,

Ishikawa²,

Tanaka³

et al. 2007

Water Environment Research

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The authors have been engaged in the development of a phosphorus recovery system capable of maintaining high recovery efficiencies, with the chemical cost suppressed. This time, they conducted demonstration tests of a fluidized bed magnesium ammonium phosphate reactor provided with a seeder reactor for the supernatant from anaerobic digestion using a pilot experimental plant with a wastewater treatment capacity of 20 m 3 /d. For the digestion supernatant with a phosphorus concentration of approximately 300 mg/L, the treated water phosphorus concentration was 10 to 25 mg/L, and the phosphorus recovery efficiency was more than 90%. Relative to the chemical cost in the case of magnesium chloride, the chemical cost in the case of magnesium hydroxide is approximately 40%. Thus, with the new system, it was possible to reduce the running cost while maintaining high recovery efficiencies. Water Environ. Res., 79, 406 (2007).

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Section: Experimental Methodsmentioning

confidence: 99%

Use of a Seeder Reactor to Manage Crystal Growth in the Fluidized Bed Reactor for Phosphorus Recovery

Shimamura¹,

Ishikawa²,

Tanaka³

et al. 2007

Water Environment Research

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“…These results suggest that the colour and phosphorous-removal performance of CSH-lime is considerably higher than that of ALC. Moriyama et al [18] demonstrated that crystal material consisting of calcium silicate hydrate can be used to remove phosphorus through crystallization, and the hydroxyapatite that is produced can be used as a fertilizer. CSH-lime may also be used as a fertilizer if the precipitated CSH-lime can be recovered.…”

Section: Difference In Characteristics and Performance Of Csh-lime Anmentioning

confidence: 99%

Simultaneous removal of colour, phosphorus and disinfection from treated wastewater using an agent synthesized from amorphous silica and hydrated lime

Yamashita

Aketo

Minowa

et al. 2013

Environmental Technology

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An agent synthesized from amorphous silica and hydrated lime (CSH-lime) was investigated for its ability to simultaneously remove the colour, phosphorus and disinfection from the effluents from wastewater treatment plants on swine farms. CSH-lime removed the colour and phosphate from the effluents, with the colour-removal effects especially high at pH 12, and phosphorous removal was more effective in strongly alkaline conditions (pH > 10). Colour decreased from 432 +/-111 (mean +/- SD) to 107 +/- 41 colour units and PO4(3-)P was reduced from 45 +/- 39 mg/L to undetectable levels at the CSH-lime dose of 2.0% w/v. Moreover, CSH-lime reduced the total organic carbon from 99.0 to 37.9 mg/L at the dose of 2.0% w/v and was effective at inactivating total heterotrophic and coliform bacteria. However, CSH-lime did not remove nitrogen compounds such as nitrite, nitrate and ammonium. Colour was also removed from dye solutions by CSH-lime, at the same dose.

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“…Physico-chemical treatments and biological nutrient removal are the most commonly used methods for the removal of phosphate from municipal and industrial wastewater (Jenkins and Hermanowich 1991;Stensel 1991;Zhao and Sengupta 1998). Although often used, they hold several disadvantages such as excess sludge production, high chemical demand, and most importantly it is difficult to achieve regulatory guidelines since only 75% to 85% of the phosphate is removed (Moriyama et al 2001).…”

Section: Introductionmentioning

confidence: 99%

Fixed bed phosphate adsorption by immobilized nano-magnetite matrix: experimental and a new modeling approach

Zach-Maor¹,

Semiat²,

Shemer³

2011

Adsorption

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Nano-sized magnetite impregnated charcoal granular activated carbon (nFe-GAC) was utilized for the removal of phosphate from aqueous solutions using a fixed bed column. The dynamic of the phosphate adsorption was analyzed using a new approach to the Thomas model based on a two-step differential sorption rate process. The initial adsorption was found to be external mass transfer controlled, while intra-particle diffusion was the predominant mechanism in the latter stage. Consequently, two kinetic coefficients were calculated for each breakthrough curve resulting in an excellent model prediction. By implementing this approach a transition point, at which diffusion becomes the predominant adsorption mechanism, can be accurately determined. The effect of varying parameters, such as feed flow rates, feed pH, initial phosphate concentrations and adsorbent bed height were examined and described using the modified Thomas model. Reaction rates increased with augmentation of the flow rates from 1 to 40 mL/min while the adsorption capacity and transition point decreased. Similar transition points were obtained for initial phosphate concentrations between 10 and 100 mg/L. The unique characteristics of the nFe-GAC were evident as it exhibited very high phosphate adsorption capacity, at a wide range of pH values (4-9) with negligible effect of competing ions and short critical bed depth.

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Development of Artificial Seed Crystal for Crystallization of Calcium Phosphate

Cited by 66 publications

References 5 publications

Use of a Seeder Reactor to Manage Crystal Growth in the Fluidized Bed Reactor for Phosphorus Recovery

Use of a Seeder Reactor to Manage Crystal Growth in the Fluidized Bed Reactor for Phosphorus Recovery

Simultaneous removal of colour, phosphorus and disinfection from treated wastewater using an agent synthesized from amorphous silica and hydrated lime

Fixed bed phosphate adsorption by immobilized nano-magnetite matrix: experimental and a new modeling approach

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