Mitigating anthropogenic nitrogen loading with constructed wetlands in a boreal climate

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University of Helsinki Finland

MITIGATING ANTHROPOGENIC NITROGEN LOADING WITH CONSTRUCTED WETLANDS

IN A BOREAL CLIMATE

Sari Uusheimo

ACADEMIC DISSERTATION

To be presented, with the permission of the Faculty of Biological and Environmental Sciences of the University of Helsinki, for public examination at lecture room Ilves, Lammi biological station (Pääjärventie 320), on April 26th 2019,

at 13 o´clock.

Hämeenlinna 2019

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AUTHORS CONTRIBUTION

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(7)

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(10)

–

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INTRODUCTION

THE INVENTION THAT CHANGED THE WORLD FOREVER

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“It may be that this solution is not the final one. Nitrogen bacteria teach '%&&&'$

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into bread.”

“Ammonia synthesis from its elements”, Nobel lecture

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CONSEQUENSES OF EXCESS REACTIVE NITROGEN

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(13)

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(14)

NITROGEN REGULATION, LOADING AND IMPORTANCE IN FINNISH WATERBODIES

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(15)

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(16)

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(17)

Figure 1. Spaceview of a cyanobacterial bloom in the Baltic Sea on July 16, 2018 (ESA Copernicus Sentinel Data, published by Finnish Environmental Institute SYKE).

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(18)

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AQUATIC NITROGEN CYCLE

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(19)

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(20)

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Figure 2. Simplified illustration of the aquatic nitrogen (N) cycle.

NITROGEN REMOVAL IN WETLANDS

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(21)

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(22)

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(24)

Figure 3. An example of a pre-experiment with

15NO3-N concentration series. D14 = denitrification of the natural ¹⁴NOx-N, D15 = denitrification based on the labeled ¹⁵NO3-N.

Standard deviation shown with error bars, n=3 for each data point.

Modified from the study I.

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AIMS OF THIS THESIS

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(27)

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;GF;=JFAF?L@=HGL=FLA9DAFL=J>=J=F;=>JGEGJ?9FA;;9J:GF

(28)

$$

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MATERIALS & METHODS

STUDY SITES

2.1.1 KOIRANSUOLENOJA CATCHMENT (I, III)

=FALJA>A;9LAGF9F<J=?MD9LAF?=FNAJGFE=FL9D>9;LGJKO=J=KLM<A=<AF9KE9DD O=LD9F< AF 9F 9?JA;MDLMJ9D O9L=JK@=< DG;9L=< AF KGML@=JF "AFD9F< JGGC 'GAJ9FKMGD=FGB9 "A? ;GDD=;LK O9L=JK >JGE 9 KE9DD O9L=JK@=< CE EGKLDQ ;GN=J=< OAL@ ;GFA>=JGMK >GJ=KL 0@= KGAD AK =9KADQ =JG<A:D=

0ACC9F=F=L9D9F<G>L@=;9L;@E=FL9J=9AK;MDLAN9L=<JNGD9=L 9DK9J=KMDL L@=LMJ:A<ALQAK@A?@DQN9JA9:D=AFL@=:JGGCO9L=J MJAF?

L@=KLM<QL@=>DGOO9K O9K;9DK9F<L@=9N=J9?= L@=GJ=LA;9DJ=L=FLAGF LAE=GF=@GMJ@%F 9;@9AFG>L@J==K=<AE=FL9LAGFHGF<KO=J=

:MADL:QL@=:JGGC+F=G>L@=;GFKLJM;L=<HGF<K9J=9G>E NGDME=G>

E O9K K=D=;L=< 9K 9 KLM<Q O=LD9F< :=;9MK= G> L@= @A?@ *+P*

;GF;=FLJ9LAGF;9\E?*D9F<L@=K@9DDGODALLGJ9DDALLGJ9D<=HL@

E E=9FO=LD9F<<=HL@E

Figure 4. Location of Brook Koiransuolenoja and the study wetland. Monitoring site of the brook water (K1) is situated upstream from the pond. The location of the sensor for measuring photosynthetically active radiation (PAR) and laboratory of Lammi Biological Station.

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2.1.2 CONSTRUCTED WETLAND OF LAMMI WASTEWATER TREATMENT PLANT (II)

0@=3G>(9EEA330,O9K;@GK=F9K9KLM<QKAL=9KALG>>=JK9HGKKA:ADALQ LG AFN=KLA?9L=FMLJA=FLJ=L=FLAGF9F<*J=EGN9D=>>A;A=F;QAF9;GD<;DAE9L=

0@=(9EEA3(61°08′83′′N, 24°99′66′′E)O9KGJA?AF9DDQ;GFKLJM;L=<AF

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O9KL=O9L=JK G> ;9 H=GHD= OAL@ K9F< K=H9J9LAGF , J=EGN9D 9F<

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L@=9N=J9?=;GF;=FLJ9LAGFAFL@=O9L=J>DGOAF?AFLGL@=3AK;9E?*+P

*(HHJGPAE9L=DQcG>L@=*DG9<AK<AK;@9J?=<AFLGL@=O=LD9F<9K*$

*

Figure 5. Constructed wetland of Lammi wastewater treatment plant, Hämeenlinnan Seudun Vesi Ltd.

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2.1.3 SURFACE WATERS WITH DIFFERING NITROGEN AND ORGANIC CARBON CONCENTRATIONS (III)

%F9<<ALAGFLGJGGC'GAJ9FKMGD=FGB9K=;LAGF L@=O9L=JKG>=A?@LGL@=J KAL=K D9C= JAN=J :JGGC KHJAF? OAL@N9JQAF?*+P*9F<+;GF;=FLJ9LAGFKAF KGML@=JF"AFD9F<O=J=AF;DM<=<LGKLM<QL@=MK=G>;GFLAFMGMKGHLA;9DK=FKGJK AF EGFALGJAF? * ;GF;=FLJ9LAGFK 09:D= K@GOK L@= *+P* 9F< +

;GF;=FLJ9LAGFK <MJAF? L@= KLM<Q JGGC (99NAGFKMGFGB9 AK 9 KE9DD KLJ=9E

>DGOAF?>JGE9H=9LD9F<9J=99F<@9K9@A?@+;GFL=FL

Table 2. Sampling sites with NOx--N and DOC or/and TOC concentrations in the studied waters.

MEASUREMENTS AND ANALYSES

2.2.1 WATER, SEDIMENT AND ENVIRONMENTAL VARIABLES

,@GLGKQFL@=LA;9DDQ 9;LAN= J9<A9LAGF ,. O9K E=9KMJ=< OAL@ 9 IM9FLME K=FKGJ,-/ 'AHH6GF=F #=JE9FQ=N=JQEAFML=K 9F<L@=K=FKGJO9K DG;9L=<;DGK=ELGL@=KLM<QKAL=AJL=EH=J9LMJ=9F<HJ=;AHAL9LAGF

<9L9O=J=G:L9AF=<>JGE0@="AFFAK@)=L=GJGDG?A;9D%FKLALML=39L=J>DGO 9F< K=<AE=FL L=EH=J9LMJ= O=J= E=9KMJ=< OAL@ 9 >DGO E=L=J )AFAAJ /;@ADLCF=;@L #=JE9FQ <MJAF? =9;@ K9EHDAF? G;;9KAGF 39L=J L=EH=J9LMJ=9F<<AKKGDN=<GPQ?=FK9LMJ9LAGF9F<;GF;=FLJ9LAGFG>L@=O9L=J O=J=E=9KMJ=<OAL@GPQ?=FE=L=J,JG+ + 5/% 1/+;GF;=FLJ9LAGF AF L@= O9L=J ;DGK= LG L@= K=<AE=FL KMJ>9;= 9KO=DD 9K + H=F=LJ9LAGF <=HL@

+, AFL@=K=<AE=FL O=J=E=9KMJ=<OAL@EA;JG=D=;LJG<=1FAK=FK=+4 =FE9JC ;GFF=;L=< LG 9 HA;G9EE=L=J , 1FAK=FK= =FE9JC /=<AE=FLK9EHD=KO=J=;GDD=;L=<:Q@9F<GJOAL@K=<AE=FLK9EHD=J

"GJ (+% 9F9DQKAK LGH K=<AE=FL ;E O9K ;GE:MKL=< 9L ] >GJ @ 39L=J K9EHD=K >GJ FMLJA=FL ;9J:GF 9F< ;@DGJGH@QDD @D 9F9DQKAK O=J=

;GDD=;L=<:Q@9F<9F<9F9DQK=<AFL@=D9:GJ9LGJQG>(9EEAAGDG?A;9D /L9LAGF

Site Coordinates NOx-N mg l^-1 DOC mg l^-1 TOC mg l^-1

Brook Laaviosuonoja 61°02'N, 24°59'S 0.040± 74.0 ± 53.0 ±

Lake Ormajärvi 61°05'N, 24°57'S 0.35± nd 7.8±

Spring Löytynlähde 61°02'N, 24°58'S 0.41 ± 1.2 ± 2.3 ±

River Luhtaanmäenjoki 60°20'N, 24°47'S 0.57 7.6 ± nd

Lake Pääjärvi 61°05'N, 25°05'S 0.85 10.0 ± nd

River Teuronjoki 61°05'N, 24°50'S 1.2 8.1 ± nd

River Vantaanjoki 60°40'N, 24°56'S 1.3 ± nd 10.0 ±

Brook Letkunoja 61°03'N, 25°05'S 2.5 7.9 ± nd

Brook Koiransuolenoja 61°03'N, 25°04'S 2.4 ± 10.6 ± nd

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"GJ <AKKGDN=< AFGJ?9FA; FMLJA=FL >J9;LAGFK 9F< <AKKGDN=< GJ?9FA; ;9J:GF 9F9DQKAKL@=K9EHD=KO=J=>ADL=J=<L@JGM?@μE>ADL=JK)ADD=P$ )=J;C )ADDAHGJ= 1/0* *+P* *$* 0,9F<,+,;GF;=FLJ9LAGFK O=J= 9F9DQR=< KH=;LJGH@GLGE=LJA;9DDQ #9DD=JQ ,DMK 0@=JEG /;A=FLA>A;

"AFD9F< 9;;GJ<AF? LG KL9F<9J<K /"/!* %/+ /"/!* %/+

/"/!*%/+ %/+ %/ J=KH=;LAN=DQ + O9K 9F9DQR=<

MKAF? 9 ;9J:GF 9F9DQR=J +J<AGJ 0+2 /@AE9<RM &9H9F 9;;GJ<AF? LG KL9F<9J</"/!*%FKLM<Q O9L=JK9EHD=KO=J=>ADL=J=<

μE *M;D=HGJ= 3@9LE9F#!$=9DL@;9J= 1/>GJ*+P*9F< +9F9DQKAK

*+P* O9K 9F9DQR=< OAL@ 9F 9MLGE9L=< >DGOAFB=;LAGF 9F9DQR=J (9;@9L -MAC@=E (9;@9L%FKLJME=FLK 1/ 9F<0+9F< +O=J=9F9DQR=<

MKAF?9@A?@L=EH=J9LMJ=;GE:MKLAGFE=L@G<0+ /@AE9<RM &9H9F

"GJ@D9F9DQKAK L@=O9L=JO9K>ADL=J=<3@9LE9F#"?D9KK>A:=J 1' 9F< >ADL=JK O=J= >J==R=< Y :=>GJ=KH=;LJGH@GLGE=LJA;9D 9F9DQKAK 12 /@AE9<RM &9H9F9;;GJ<AF?LGKL9F<9J</"/

2.2.2 SEDIMENTAL NITROGEN REMOVAL MEASUREMENTS AND ANALYSES

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@9F<GJOAL@K=<AE=FLK9EHD=J =FALJA>A;9LAGFJ9L=KO=J=E=9KMJ=<

MKAF?L@=AKGLGH=H9AJAF?L=;@FAIM=%,0*A=DK=F .AK?99J<,=L=JK=F=L 9D O@A;@ AK <=K;JA:=< =9JDA=J AF K=;LAGF ,GJGKALQ G> L@=

KLM<A=<K=<AE=FLO9K;9D;MD9L=<>JGELGHK=<AE=FL;E

%FL@=9?JA;MDLMJ9DO=LD9F< *HJG<M;LAGFO9KKLM<A=<9DDQ=9JJGMF<MKAF?

D9:=D=< K=<AE=FL ;GJ=K F AF;M:9L=< AF 9E:A=FL L=EH=J9LMJ= 9F< DA?@L

;GF<ALAGFKAFL@=>A=D<MKAF?GF=D9:=D;GF;=FLJ9LAGFμEGD'*+LGL9D F0@=9N=J9?=*+P*;GF;=FLJ9LAGFAFL@=9?JA;MDLMJ9D:JGGCO9K μEGD*DE?*D%F9<<ALAGFLGK=9KGF9DN9JA9LAGF <AMJF9DN9JA9LAGF O9KAFN=KLA?9L=<LOA;=AF9@GMJ=PH=JAE=FLAFM?MKL9F<

29DA<ALQ G> L@= E=L@G< AF L@= KLM<A=< K=<AE=FL O9K N=JA>A=< MKAF?

;GF;=FLJ9LAGFK=JA=KAF;M:9LAGFKOAL@N−labeled potassium nitrate (50, 100, 9F<μEGDG>*+* 9LGE /A?E9D<JA;@

%F L@= 330, O=LD9F< *HJG<M;LAGF O9K E=9KMJ=< LOA;= MKAF? 9

*+;GF;=FLJ9LAGFK=JA=KAFL@=FGFN=?=L9L=<9F<N=?=L9L=<9J=9<MJAF?

L@=KMEE=J0@=9N=J9?=*+P*;GF;=FLJ9LAGF>DGOAF?>JGEL@=330,AFLG L@=3 O9KμEGD*DE?* D 0@=*+P*;GF;=FLJ9LAGF O9K 9KKME=< LG := @A?@=J AF L@= FGFN=?=L9L=< 9J=9 L@9F L@= N=?=L9L=< 9J=9 GF;=FLJ9LAGFKG>'*+* 9F<μEGDO=J=MK=<AF%,0 AF;M:9LAGFKAFL@=N=?=L9L=<9J=9;GJ=K 9F< 9F<μEGD AF L@= FGFN=?=L9L=< 9J=9 %F ;GD< K=9KGF *HJG<M;LAGF :Q <=FALJA>A;9LAGF 9F<9F9EEGP 9KO=DD9K*+HJG<M;LAGF O=J=E=9KMJ=<OAL@9K=JA=KG>

Mitigating anthropogenic nitrogen loading with constructed wetlands in a boreal climate