Pilot-scale study of phosphorus recovery through struvite crystallization – II: Applying in-reactor supersaturation ratio as a process control parameter

2003 ◽  
Vol 2 (6) ◽  
pp. 473-483 ◽  
Author(s):  
Ali Adnan ◽  
Frederic A Koch ◽  
Donald S Mavinic
Keyword(s):  
Process Control ◽  
Control Parameter ◽  
Pilot Scale ◽  
Phosphorus Recovery ◽  
Supersaturation Ratio ◽  
Struvite Crystallization

Phosphorus recovery from wastewater through struvite formation in fluidized bed reactors: a sustainable approach

2008 ◽  
Vol 57 (2) ◽  
pp. 175-181 ◽  
Author(s):  
M. I. H. Bhuiyan ◽  
D. S. Mavinic ◽  
F. A. Koch
Keyword(s):  
Wastewater Treatment ◽  
Fluidized Bed ◽  
Treatment Plant ◽  
Pilot Scale ◽  
Phosphate Removal ◽  
Phosphorus Recovery ◽  
Molar Ratio ◽  
Supersaturation Ratio ◽  
Environmentally Sustainable ◽  
Agriculture Sector

Recovery of phosphate as struvite (MgNH4PO4·6H2O), before it forms and accumulates on wastewater treatment equipment, solves wastewater treatment problems and also provides environmentally sustainable, renewable nutrient source for the agriculture sector. A pilot-scale fluidized bed reactor was used to recover phosphate through crystallization of struvite, from anaerobic digester centrate at the Lulu Island Wastewater Treatment Plant, Richmond, British Columbia, Canada. The desired degree of phosphate removal was achieved by maintaining operating pH (8.0–8.2), and recycle ratio 5–9, to control the supersaturation conditions inside the reactor. The performance of the system was found to be optimal when in-reactor supersaturation ratio was 2–6. Among several other operating parameters, apparent upflow velocity and magnesium to phosphate molar ratio were also found important to maintain system performance, both in terms of efficiency of phosphate removal and recovery as struvite pellets. A narrow window of upflow velocity (400–410 cm/min) was found to be effective in removing 75–85% phosphate. TOC level inside the rector was found to affect the performance to some extent. The precipitation potential of struvite could be successfully predicted using a thermodynamic solubility product value of 10−13.36 and its temperature dependence in PHREEQC.

Phosphorus recovery from wastewater by struvite crystallization: Property of aggregates

2014 ◽  
Vol 26 (5) ◽  
pp. 991-1000 ◽  
Author(s):  
Zhilong Ye ◽  
Yin Shen ◽  
Xin Ye ◽  
Zhaoji Zhang ◽  
Shaohua Chen ◽  
...  
Keyword(s):  
Phosphorus Recovery ◽  
Crystallization Property ◽  
Struvite Crystallization

scholarly journals Critical conditions of struvite growth and recovery using MgO in pilot scale crystallization plant

2020 ◽  
Vol 81 (12) ◽  
pp. 2511-2521 ◽  
Author(s):  
Nari Park ◽  
Hyangyoun Chang ◽  
Yeoju Jang ◽  
Hyunman Lim ◽  
Jinhong Jung ◽  
...  
Keyword(s):  
Pilot Plant ◽  
Wastewater Treatment Plants ◽  
Weight Fraction ◽  
Dry Weight ◽  
Xrd Analysis ◽  
Pilot Scale ◽  
Critical Conditions ◽  
Side Stream ◽  
Struvite Crystallization ◽  
Ph Range

Abstract The struvite crystallization process can recover struvite crystals as a valuable slow-release fertilizer from the side stream of wastewater treatment plants (WWTPs). The purpose of this study is to demonstrate the crystal growth characteristics and determine the appropriate recovery criteria for a struvite crystallization pilot plant. A pilot plant (8.6 m3/d) was designed with a feeding system of MgO (magnesium oxide), a pH controller, and a hydrocyclone for recovering struvite; the plant was operated for 42 hours at a pH range of 8.25–8.5. The removal efficiencies for PO4-P and NH4-N were 82.5–90.7% and 13.4–22.9%, respectively. The struvite recovered from the hydrocyclone was sifted using standard sieves and analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The dry weight fraction of the precipitate in the 300–600 μm range increased gradually from 7% to 74% in 18 hours. The XRD analysis revealed that the crystalline structure of the precipitate in the 150–600 μm range indicates struvite without any peaks of MgO, Mg(OH)2, and MgCO3. This indicates that the critical conditions for recovering struvite from the side-stream of WWTPs are an operation period of 18 hours and a crystal size greater than 300 μm.

P-Recovery from sewage by seeded crystallisation in a pilot plant in batch mode technology

2011 ◽  
Vol 63 (2) ◽  
pp. 339-344 ◽  
Author(s):  
A. Ehbrecht ◽  
S. Schönauer ◽  
T. Fuderer ◽  
R. Schuhmann
Keyword(s):  
Pilot Plant ◽  
Pilot Scale ◽  
Phosphorus Recovery ◽  
Batch Mode ◽  
Mineral Phases ◽  
Phosphate Mineral ◽  
P Recovery

P-Recovery from actual sewage by P-RoC-technology (Phosphorus Recovery by Crystallisation of phosphate mineral phases from waste- and processwater) was studied in a pilot scale. Therewith the practicability of the pilot plant was tested and the quality of the so generated products was investigated.

scholarly journals A colony count model for the control of drinking water distribution systems

2005 ◽  
Vol 9 (2) ◽  
pp. 189-205
Author(s):  
A. Kerneis ◽  
A. Déguin ◽  
M. Feinberg
Keyword(s):  
Organic Matter ◽  
Process Control ◽  
Residence Time ◽  
Distribution Systems ◽  
Control Parameter ◽  
Control Parameters ◽  
Supply Water ◽  
Biodegradable Organic Matter

The purpose of this study is to select a process control parameter for monitoring microbial regrowth in a network and to develop a more accurate and relevant quality control of supply water. Two parameters were examined as potential process control parameters: the water residence time in the network and the concentration of biodegradable organic matter. Residence time calculations were carried out and validated by tracer studies in a branched network and then in a simply looped network. The measurement of the natural dissolved organic carbon (DOC) consumption in the network was preferred to the determination of any in vitro biodegradation. The measurement of consumption requires the determination of DOC in treated water and in supply water. It is simpler and less expensive than other biodegradable organic matter determinations. A model for colony counts as a function of the residence time was developed in order to demonstrate that this parameter can be used for process controlling. This model was very well adjusted to data collected in a network in winter, spring and summer. This process control parameter was then used in order to locate and estimate the quantity of water whose colony counts exceed the European directive guide level. Accurate correlation measurements between colony counts and DOC consumed in the network were carried out in three distinct systems. No significant correlations were measured. For these three networks, biodegradable organic matter measurements based on DOC determinations were demonstrated to be unreliable process control parameters for monitoring bacterial regrowth.

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