Separation of Struvite from Mineral Fertilizer Industry Wastewater

Matynia, A.; Wierzbowska, B.; Hutnik, N.; Mazieńczuk, A.; Kozik, A.; Piotrowski, Krzysztof

doi:10.1016/j.proenv.2013.04.103

Cited by 26 publications

(14 citation statements)

References 9 publications

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“…The shape of particles recovered from solutions with humic acid was triangle-shaped, which was quite distinct from the others precipitates, and may be due to its ability to block active sites and adsorb to the newly formed crystallites, thus influencing their growth and transformation. Moreover, the morphology of the precipitates could also be affected by the reaction crystallization process, and some previous researches revealed that the solids could present the tubular forms and trough shape [38,39] or an agglomeration of single orthorhombic crystals in continuous mode [22]. It was supposed that this was the net effects of the impurities present in the wastewater and technological parameter of reaction crystallization process.…”

Section: Discussionmentioning

confidence: 99%

Effects of organic substances on struvite crystallization and recovery

Zhang

Zhao

et al. 2015

Desalination and Water Treatment

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A B S T R A C TThe effects of organic substances on struvite crystallization and recovery from synthetic wastewater were investigated. Experiments were completed during trials lasting 5 days using a pilot reactor with two concentric stainless steel meshes as seed material. Various concentrations of organics were added to synthetic CO 2 -saturated solutions and the pH was elevated from an initial value of 6.5 using a degassing technique. The results showed the presence of glucose, humic acid, and citric acid could reduce the struvite mass accumulating rates as compared to solutions without organic additives. In addition, glucose as an additive could significantly promote the removal rate of phosphorus as opposed to the other two. The mechanisms of the inhibitory effects are specially focused on the fact citric acid is able to complex with Mg 2+ , and NH þ 4 in solution, while humic acid or glucose are able to adsorb onto the crystal surface. The recovered precipitates were analyzed using X-ray diffraction and were proven to have high purities. The morphologies of the precipitates were examined using scanning electron microscopy and found struvite particles aggregated together showing an irregular block shape, with the exception of particles recovered from solutions with humic acid, which showed a triangle-like shape.

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Section: Discussionmentioning

confidence: 99%

Effects of organic substances on struvite crystallization and recovery

Zhang

Zhao

et al. 2015

Desalination and Water Treatment

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“…According to the IC analysis, urine has an average of 950 ppm of phosphate ions. The best ratio Mg:P reported in the literature is 1:1.2 (Huang et al., 2012, Hutnik et al., 2013a, Hutnik et al., 2013b, Koralewska et al., 2009, Kozik et al., 2011, Matynia et al., 2013), and therefore this is the ratio used during the experiments. A total of 3 g MgCl 2 ·6H 2 O per litre of urine was added to fresh urine every day.…”

Section: Methodsmentioning

confidence: 99%

“…(2011) obtained an increased crystal size of 67 μm after 1 h reaction at pH 9 when the molar ratio was 1:1.2 compared to 80 μm when the molar ratio was 1:1. Therefore, the optimum PO 4 :Mg ratios are between 1:1 and 1:1.2, since larger crystals and high efficiency are obtained at those ratios (Koralewska et al., 2009, Matynia et al., 2013, Huang et al., 2012, Hutnik et al., 2013a, Hutnik et al., 2013b). …”

Section: Introductionmentioning

confidence: 99%

Enhanced MFC power production and struvite recovery by the addition of sea salts to urine

et al. 2017

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Urine is an excellent fuel for electricity generation in Microbial Fuel Cells (MFCs), especially with practical implementations in mind. Moreover, urine has a high content in nutrients which can be easily recovered. Struvite (MgNH4PO4·6H2O) crystals naturally precipitate in urine, but this reaction can be enhanced by the introduction of additional magnesium. In this work, the effect of magnesium additives on the power output of the MFCs and on the catholyte generation is evaluated. Several magnesium sources including MgCl2, artificial sea water and a commercially available sea salts mixture for seawater preparation (SeaMix) were mixed with real fresh human urine in order to enhance struvite precipitation. The supernatant of each mixture was tested as a feedstock for the MFCs and it was evaluated in terms of power output and catholyte generation. The commercial SeaMix showed the best performance in terms of struvite precipitation, increasing the amount of struvite in the solid collected from 21% to 94%. Moreover, the SeaMix increased the maximum power performance of the MFCs by over 10% and it also changed the properties of the catholyte collected by increasing the pH, conductivity and the concentration of chloride ions. These results demonstrate that the addition of sea-salts to real urine is beneficial for both struvite recovery and electricity generation in MFCs.

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“…Alkaline pH increases supersaturation with respect to struvite as it decreases its solubility . However, raising pH may cause co‐precipitation of heavy metal hydroxides with struvite and thus reduce the value of the precipitate as a potential soil fertilizer . pH values below 7, although they are not favorable for P and N recovery by crystallization, due to the decrease of supersaturation with respect to struvite, are considerably less prone to coprecipitation and to the uptake of heavy metals on the precipitate .…”

Section: Introductionmentioning

confidence: 99%

Phosphorus recovery from simulated municipal wastewater (SMW) through the crystallization of magnesium ammonium phosphate hexahydrate (MAP)

Mpountas

Papadakis

Koutsoukos

2017

J of Chemical Tech & Biotech

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BACKGROUND Phosphorus and nitrogen recovery from municipal and/or industrial wastewater treatment plants in the form of magnesium ammonium phosphate hexahydrate (MgNH4PO4·6H2O, MAP, Struvite) is an attractive alternative for the valorization of wastes. Although efforts have been focused on the recovery of nitrogen and phosphorus nutrients from wastewater at alkaline pH, removal of these nutrients in weakly acid pH is still challenging. The advantage of acid pH is that the precipitation of heavy metals in the form of insoluble hydroxides is avoided provided that their concentrations are relatively low. RESULTS The metastable zone width of solutions, supersaturated with respect to MAP at pH 6.50 was investigated. The kinetics of MAP formation both in unseeded and in seeded solutions was investigated in batch reactors at constant supersaturation. The rates of crystal growth of MAP on seed crystals showed a parabolic dependence on the relative supersaturation. The concentration of the inoculating seed crystals affected the rates of crystal growth. CONCLUSIONS It is possible to crystallize MAP at pH values of 6.50 provided that the supersaturation is sufficient. From the rate dependence on relative supersaturation (parabolic) it was concluded that the crystal growth mechanism was surface diffusion controlled for the integration of the growth units at the active crystal growth sites. Secondary nucleation, depending on the solution supersaturation, was observed within the stable domain of the metastable zone. The morphology of MAP seed crystals remained unchanged, while the mean particle size increased reaching comparable sizes irrespective of the degree of supersaturation. © 2017 Society of Chemical Industry

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Separation of Struvite from Mineral Fertilizer Industry Wastewater

Cited by 26 publications

References 9 publications

Effects of organic substances on struvite crystallization and recovery

Effects of organic substances on struvite crystallization and recovery

Enhanced MFC power production and struvite recovery by the addition of sea salts to urine

Phosphorus recovery from simulated municipal wastewater (SMW) through the crystallization of magnesium ammonium phosphate hexahydrate (MAP)

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