Transport and Fate of Ammonium Supply from a Major Urban

Transport and Fate of Ammonium Supply from a Major Urban
Wastewater Treatment Facility in the Sacramento River, CA.
Alexander E. Parker, R. C Dugdale, F. P. Wilkerson, A. Marchi, J. Davidson-Drexel, J. Fuller, S. Blaser.
Romberg Tiburon Center, San Francisco State University. 3152 Paradise Drive, Tiburon, CA 94920, [email protected]
US5 US 4
US6
2
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649
US 2
S anaqui
Jo
1
Map of the study site with approximate
station locations (red circles) and names.
Sampling occurred in March (data shown
here) and April 2009.
-Substantial NH4 (red) and PO4 (line) loading
from SRWTP at RM44
-[DIN] similar downstream of SRWTP with
conversion of NH4 to NO3 (blue) , potentially
due to nitrification.
APPROACH
B
C
D
8x103
6x10
4x10
A effluent addition experiment was conducted using water collected at
GRC (NH4 ≤1 uM). Serial additions of 24-hr composite SRWTP effluent
(2mM NH4) was made (1:25 to 1:5000 dilution) to 160ml incubation
bottles and incubated with 13C and 15NH4 or 15NO3 for 4-hr around local
noon.
3
2
I-80
Two transects were completed in March (data presented here) and April
2009 using the RV Questuary. Stations were occupied on an outgoing
tide. At each station a CTD profile was made (A), with samples collected
for flow cytometry (B), nutrients and chl-a (C), and 24-hr primary
production and phytoplankton nitrogen uptake rates (D).
3
SRWTP
0
Oak
Hod XCh ISL
Rio
649
US-3
US-5
5
0
1
h-1
-1
-1
2
20
18
Effluent
16
NH4Cl
1
0
-Primary production decreased along
Sacramento River and increased in
Suisun and San Pablo Bays.
-Phytoplankton N use shifted from
NO3 uptake (blue) to NH4 uptake (red)
at RM44.
1x104
fluor. particles 5-50µm
4
10
SRWTP
20
10
100
16
12
1
10
NH4, umol L-1
100
-1
NH4, umol L
Decreased primary production with
increasing effluent NH4. No effect for
NH4Cl.
Phytoplankton NO3 uptake versus NH4 additions
either as effluent (red circles) or as NH4Cl (yellow
circles).
SRWTP effluent stimulated NH4 uptake
up to 8uM NH4.
Decreased NH4 uptake with increasing
effluent >8uM NH4 (1:250 dilution). No
effect for NH4Cl.
40
2x10
3
0x10
0
Phytoplankton biomass decreased along
Sacramento River and then Increased
in Suisun and San Pablo Bays.
Diatoms dominant upstream and in
western Suisun and San Palbo Bays.
Shift in numerical dominiance of cells <5
in upstream staitons and >5 in Western
Suisun and San Pablo Bays
US13
Primary
Production
NH4
Uptake
NO3
Uptake
Effluent
<8uM NH4
-
+
-
Effluent
>8uM NH4
-
-
-
No effect
+
-
30
3
6
Green Algae
Diatoms
Cryptophytes
Chl a GF/F
fluor. particles 1-5µm
particles (# * ml-1)
2. Investigate experimentally, the primary production response by
phytoplankton to additions of wastewater effluent.
[pigments] µg * L-1
8
Phytoplankton community assessed by flow
cytometer, bbe Fluororobe, and extracted
chlorophyll-a
15
3
22
-1
-DIN:P ca. 16; favorable for phyto-plankton
growth.
1. Characterize nutrients, primary production and phytoplankton
standing stocks along a 75 km Sacramento River transect during spring
(March, April, May)
C
ITO80
W
OA
G K
R
RM C
4
HO 4
KED
C N
RS
L3
7
IS
65 L
7A
65
5
65
3
64
US9
US2
US3
US4
US5
U 6
USS7
13
ITO80
W
OA
G K
R
RM C
44
HO
KE D
N
C
RS
L3
7
IS
65 L
7A
65
5
65
3
64
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US2
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US 7
13
0
NO3
Phytoplankton NH4 uptake versus NH4 additions either
as effluent (red circles) or as NH4Cl (yellow circles).
3
-1
n
ANTI OCH
GOALS
A
20
655
653
20
NH4
Primary Production, ug C L-1h-1
PABLO
US13BAY
2
40
4
25
-1
San Pablo
SANBay
UN
IS
SU Y
BA
657
3
SRWTP
Primary production versus NH4 additions either as
effluent (red circles) or as NH4Cl (yellow circles).
NO3 uptake, x10 umol L h
L37
ISL
RI O VISTA
DIN (umol L )
CRS
Suisun Bay
-1
HOD
KEN
PO4
NO3
NO2
NH4
Urea
60
30
-1
4
GRC
RM44
SRWTP
-1
OAK
Sacramento River
San Francisco
Estuary
S
Primary Production, , umol C L , d
TOW
EFFLUENT ADDITION EXPERIMENT
Primary production (line) and NO3 (blue) and NH4 (red)
uptake along the Sacramento River, C and N uptake
scaled to 6.6:1, i.e. Redfield Ratio
-1
I80
California
PO4 (umol L )
Effluent from wastewater treatment
plants (WWTP) represent a major
source of anthropogenic nitrogen to
coastal and estuarine waters. In the
Sacramento River, ammonium (NH4)
loading from the Sacramento Regional
Wastewater Treatment Plant (SRWTP)
has increased three-fold since the
1980’s and represents 90% of the
river’s total NH4 load. Despite the
large WWTP influence on river
nitrogen, little is known about how
riverine phytoplankton may respond to
nutrient enrichment or the potential
consequences of elevated NH4
downstream in the San Francisco
Estuary and Delta.
Nutrient concentrations along Sacramento
River, March 2009. DIN and P scaled to 16:1
i.e. Redfield Ratio.
NH4 Uptake,x10 umol L
RIVER TRANSECTS – MARCH 2009
N Uptake, umol N L d
INTRODUCTION
20
10
0
1
10
NH4, umol L
100
-1
Phytoplankton NO3 uptake was
inhibited by both effluent and NH4Cl.
NH4Cl,
0 to 100uM
Summary of SRWTP effluent effects on primary
production and phytoplankton N uptake.
MAJOR FINDINGS
MAJOR FINDINGS
-SRWTP effluent reduced primary production by ca. 25% over no addition.
-The SRWTP has a large effect on both the magnitude of nutrient concentration and
type of inorganic nitrogen (NO3 or NH4) in the Sacramento River.
-SRWTP effluent enhanced NH4 uptake at concentrations <8umol, then effluent inhibited
NH4 uptake at concentrations ≤ 8umol L-1.
-The result of the SRWTP is eutrophication of the Sacramento River and, for
phytoplankton, a conversion of the river from an environment driven by NO3 uptake to
one driven by NH4.
- NO3 uptake was inhibited by both effluent and NH4Cl, suggesting that the presence of
NH4 inhibits phytoplankton NO3 uptake
-Nitrification is likely important in controlling the type of nitrogen in the river.
ACKNOWLEDGMENTS
-It is unclear from these data what drives declines in primary production or chl-a. The
Sacramento River and San Francisco Estuary exhibited diverse phytoplankton
communities along the transect.
We wish to thank the SRWTP and the Central Valley Regional Water Quality Control
Board for assistance with study design and logistical support. Dr. A. Mueller-Solger for
use of bbe Fluoroprobe and the crew of the RV Questuary for shipboard support. The
project was funded by The California State Water Quality Control Board and the State
Water Contractors.