Table 2: Summary of fertilizer-phosphorus (P)-source fertilizer grade and mean pH and nutrient concentrations [± standard error (SE)] and water solubility.

Fertilizer-P sourcea

Measured fertilizer gradeb

pH

Nutrient concentration (± SE)

 

Fertilizer-P source water solubilityd

N

P

Mg

 

 

 

__________________ % ____________________

 

ECSTReal

3-35-0

7.2 (< 0.1)

3.3 (0.1)

15.5 (0.2)

13.6 (0.3)

2 - 3.8%

ECSTSyn

5-37-0

-c

5.1 (0.2)

16.1 (0.3)

12.7 (0.3)

2 - 3.8%

MAP

11-52-0

4.4 (0.02)

10.7 (0.1)

22.7 (0.2)

1.5 (< 0.1)

85 - 90%

CPST

6-27-0

8.8 (0.13)

5.7 (0.2)

11.7 (0.2)

8.3 (0.2)

4%

a Electrochemically-precipitated synthetic struvite (ECSTSyn), wastewater derived electrochemically-precipitated struvite (ECSTReal), monoammonium phosphate (MAP), and chemically-precipitated struvite (CPST).

b Measured fertilizer grade expressed as % N - P2O5 - K2O.

c Limited ECSTSyn supply prohibited pH determination.

dFertilizer characteristic not determined through lab analysis.