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>JGE L@= 330, "A? /AEMDL9F=GMKDQ AF *GN=E:=J L@= +
;GF;=FLJ9LAGF O9K @A?@ 0@= J=9KGF >GJ DGO *+P* AF &MDQ O9K L@= KM<<=F E9KKAN= AF;J=9K= AF O9KL=O9L=J NGDME= GJA?AF9LAF? >JGE 9 /;GML;9EH G>
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:GL@ KLM<Q Q=9JK AF *GN=E:=J L@= *$* DG9< J=D9LAN= LG *+P* DG9<
AF;J=9K=<KM??=KLAF?L@=FALJA>QAF?EA;JG:=KAFL@=330,O=J=KM>>=JAF?>JGE 9;GD<K;@G;C :MLO=J=9:D=LG9;;DAE9LAR=?J9<M9DDQ<MJAF?L@=OAFL=J0@AKAK AF<A;9L=<:QL@=AF;J=9K=<J=D9LAN=K@9J=G>*+P*<AK;@9J?=<LGL@=O=LD9F<
Figure 8. The variation of the C:N ratio in the wastewater treatment plant discharge into the wetland as well as in the wetland outlet.
0@= O<GEAF9L=<<=FALJA>A;9LAGFAFL@=N=?=L9L=<DALLGJ9DK=<AE=FLG>L@=
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NITROGEN RETENTION (II)
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>9;LGJK>GJ=>>A;A=FL*J=EGN9D AF3KJ=;=ANAF?J9OGJLJ=9L=<O9KL=O9L=JK A= LJ=9LE=FL O=LD9F<K OAL@ N9JA9:D= *$**+P* DG9<K JAP 2QE9R9D%LAK9;@A=N=<:Q;J=9LAF?<A>>=J=FLEA;JG=FNAJGFE=FLKOAL@AF L@=O=LD9F< =?K=IM=FLA9DO=LD9F<:9KAFKOAL@<A>>=JAF?GPQ?=F;GF<ALAGFK
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Table 4. Total nutrient retention (%) in the study II. Minus indicates that more of the compound in question is being produced in the wetland than it receives from the wastewater treatment plant.
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0
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%2–4%
%;=;GN=JH=JAG<K
4%%–%%%
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;GN=J H=JAG< ;GMD< := L@= @A?@ 9D?9= :AGE9KK HJG<M;=< :=LO==F )9Q 9F<
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Figure 9. Average change in NH4+-N concentration between Lammi CW outlet and inlet (II).
Negative change indicates NH4+-N retention, positive change NH4+-N release. Ice-cover periods marked with grey areas.
Figure 10. Temperature (line) and oxygen saturation (columns) in the WWTP wetland discharge between 25 March 2015 and 15 March 2017. Ice-cover periods are indicated with gray areas (II).
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Table 5. Average total nitrogen retention rates in constructed wetlands treating agricultural or municipal wastewaters in cold climate.
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