|
KMID : 1025520090510040337
|
|
Journal of Animal Science and Technology
2009 Volume.51 No. 4 p.337 ~ p.342
|
|
|
Microwave Irradiation as a Way to Reutilize the Recovered Struvite Slurry and to Enhance System Performance
|
|
Cho Joon-Hee
Lee Jin-Eui
Ra Chang-Six
|
|
|
Abstract
|
|
|
|
The feasibility of reutilization of magnesium ammonium phosphate(MAP) or struvite slurry recovered from the process through microwave irradiation was studied in this experiment. For this purpose, 4 different operations were performed with or without Mg source addition and different levels of MAP recycled in a batch reactor. Dissolution rate of MAP, NH4+ elimination pattern and physicochemical changes of MAP during microwave irradiation were also studied. The result showed that only 33% orthophosphate(PO4-P) and 27% NH4-N removal occurred without adding any external Mg source(run A), whereas 87% PO4-P and 40% NH4‐N removed when 1.0 M ratio of MgCl2 (run B) was added based on PO4-P in influent. Although the addition of 1.0 molar ratio of microwave irradiated MAP (Run C) removed lower PO4-P and NH4-N than 1.0 M MgCl2 (run B), PO4-P removal was double when compared with no Mg addition (run A). Addition of half MAP and half MgCl2 (run D) showed the similar removal efficiency (88% PO4-P and 35% NH4-N) with sole MgCl2 addition (run B). Based on these results, the reutilization of MAP irradiated by microwave would be a feasible way to enhance the removal efficiencies of N and P, as well as curtail the Mg chemical usage. Track study showed that NH4-N gradually increased at initial stage of microwave irradiation of MAP, and then started eliminating from liquor as temperature increased over 45℃. Dissolution rate of PO4－3 during microwave irradiation was proportional to the initial MAP concentration, having 0.0091x0.6373 mg/sec. It was found from the scanning electron microscope (SEM) study that physical structure of MAP crystal started breaking down into small cube granules within very short time by electromagnetic vibration force during microwave irradiation and then gradually melted down into solution.
|
|
|
KEYWORD
|
|
|
Microwave, Struvite, MAP, MgNH4PO4(6)H2O, Swine wastewater
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|