wu xuefei
Post on 29-May-2015
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The conversion of ammonium and nitrate on the growth of the two duckweed
—— Lemna perpusilla and Spirodela oligorrhiza
Name: Wu Xuefei Major: Environmental Science
Key Words
nitrogen 氮( N) ammonium 铵态氮( NH4
+ ) nitrate 硝态氮( NO3
-) duckweed 浮萍 Lemma perpusilla 稀脉浮萍 Spirodela oligorrhiza 少根紫萍
Why choose duckweed?
Content
Experimental considerations
Method
Expected result
Choose DuckweedChoose Duckweed
Why?
High removal rate of
nitrogen
Animal foodRich in protein
Growing rapidly
Harvest conveniently
Experimental Considerations
• In order to train duckweed to use ammonium in water,
• convert nitrate in the water into ammonium gradually, and see if the two kinds of duckweed can grow well
• Because duckweed prefers to absorb nitrate to ammonium, and excessive ammonium can be toxic to duckweed.
Hutner nutrient solution
nutrients Concentration (mg/L)
NH4NO3 20
CaCO3 15
MgSO4•7H2O 50
K2PO4 40
H3BO3 1.0
MnSO4•H2O 1.54
ZnSO4•7H2O 6.59
Na2MoO4•2H2O 2.52
CuSO4•5H2O 0.39
CoSO4•7H2O 0.09
FeSO4•7H2O 25
Na2EDTA 5
Footnote:NH4
+ : NH4ClNO3
- : KNO3
Method
0.05mmol/L N
n NH4+ : n
NO3-
1 5:0
2 4:1
3 3:2
4 2:3
5 1:4
6 0:5
1.0mmol/L N
n NH4+ : n
NO3-
7 5:0
8 4:1
9 3:2
10 2:3
11 1:4
12 0:5
5mmol/L N
n NH4+ : n
NO3-
13 5:0
14 4:1
15 3:2
16 2:3
17 1:4
18 0:5
• 80% NO3-—N 20% NH4
+—N
100% NO3-—N
80% NO3-—N 20% NH4
+—N
60% NO3-—N 40% NH4
+—N 40% NO3-—N 60% NH4
+—N
20% NO3-—N 80% NH4
+—N
100% NH4+—N
Every three days
If the experiment is successful, we can certainly raise the capacity that
duckweedremoves the ammonium in wastewater.
Expected result
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