Environmental Engineering Reference
In-Depth Information
9
b
6
3
0
0
5000
10000
Leaching volume(mL)
9
c
6
3
0
0
2000
4000
6000
Leaching volume(mL)
9
d
6
3
0
0
5000
10000
15000
Lea ching volume(mL)
Figure 1. The effects of four low-molecular-weight organic acids on the soil P release with leaching (a:
citric acid; b:oxalic acid; c: malic acid; d: acetic acid).
2.2. Curves of Soil Phosphorus Leaching by Low Molecular Weight Organic
Acids in Different Concentrations
Figure 2 shows the leaching curves of phosphorus when citric acid and malic acid in
different concentrations were used to leach the soil column. When oxalic acid and acetic acid
with a concentration of 1mmol L
-1
were used to leach the soil, before the point of 12,000ml
the total amount of phosphorus leached was 0. For the citric acid and malic acid with a
concentration of 0.1mmol L
-1
, before the point of 6,000ml the total amount of phosphorus
leached was 0. The total amounts of phosphorus leached by citric acid and malic acid in a
concentration of 1mmol L
-1
were 129.7 and 17.3mg kg
-1
, respectively (Table 3).
