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Chris Gammons, Montana Tech

Diel cycling of nutrients

Big Hole River, Montana

Silver Bow Creek, Montana

What species of interest?

NITROGEN

PHOSPHORUS

Nitrate

Nitrite

NO3-

Orthophosphate

Nitrous oxide

NO2N2O N2

Organic-P Suspended solids

H2PO4-, HPO4-2

Nitrogen

Ammonia

PO4 adsorbs strongly to carbonates, hydrous metal oxides

Organic-N Suspended solids

NH4+ (NH3)

What could be going on with N and P?

Diurnal changes in rate of uptake by biota Diurnal changes in delivery rate from hyporheic or benthic zones Diurnal redox cycles

Sorption/desorption of P onto carbonates, HFO, etc.. Others...?

Nitrification (ammonia + O2 nitrate) Denitrification (nitrate + org. C N2) Anammox (ammonia + nitrate N2)

Nutrient cycling below sewage point sources

Total N mg/L ammonia

denitrification, plant uptake

nitrate Distance, time

"Dead zone"

Diurnal processes

· Rate of ammonia oxidation is faster in warm water · Rate of denitrification faster in warm water · Diurnal patterns in nutrient uptake by plants, algae

(work in progress, grad student John Babcock)

Nutrient cycling in Silver Bow Creek

15

90

SBC-3 SBC-2

Silver Bow C ree k

WWTP SBC-1

o St rm

n ai Dr

Butte

LAO

15

Basin

Montana Pole

Creek

Blacktail Creek

N

Hypereutrophic conditions due to poorly treated municipal wastewater (WWTP)

5.0 4.5 4.0

5.00

Nitrate-N

Concentration (mg/L)

4.50 4.00 3.50 3.00 2.50 2.00 1.50 1.00 0.50 0.00 8:00

Concentration (mg/L)

3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 8:00

Ammonia-N

Ammonia-N

Nitrate-N

12:00 16:00 20:00 0:00 4:00 8:00

12:00

16:00

20:00

0:00

4:00

8:00

WWTP

N

1.36 miles ~3 hours 0.74 mi.

Faster rate of microbial oxidation of ammonia in warm day vs. cool night Less O2 available for ammonia oxidation at night

Silver Bow Creek at SBC-3

10 9 8

Dissolved Oxygen (mg/L)

7 6 5 4 3 2 1 0 8:00

12:00

16:00

20:00

0:00

4:00

8:00

Harrison et al. (2005)

Diel variations in N species in a sewage-rich canal in Mexico Like Silver Bow Creek, see decrease in NO3- and increase in NH4+ at night. Water column anoxic at night. Big swings in N2O... possible role of rivers in global N2O cycling?

temperature

Continuous data collected using nitrate electrode

Scholefield et al. (2005)

nitrate

River Taw, SW UK

http://www.tawriver.co.uk/sticklepath/images/rivertaw.jpg

Scholefield et al. (2005) River Taw, UK

Manual data (samples collected by hand and analyzed in lab)

Conclusions of Scholefield et al.:

Diel cycles in N, P are probably biological in origin Cannot discount possible role of physical mixing of water sources Further work is needed on mechanisms

plant uptake? Denitrification? (faster in day*)?

*see Laursen and Seitzinger, 2004

Evidence from other Montana streams

0.25

dissolved nitrate, mg/L as NO3

MWB-3

Brick and Moore, 1996 Clark Fork River, Montana

0.20

0.15

0.10 1200 1800 0000 Aug-17-2005 0600 1200 1800 Aug-18-2005 0000 0600

Gammons et al., 2007 Mill-Willow Bypass, MT

Big Hole River atAugust 1-2, 2002 Wisdom - Wisdom, MT

60 50 40 30 20 10

P, As, and pH as Function of Time

509.0 P (EPA) ppb

PO4-P

8.7 8.4 8.1 P As x 10 pH

P, As Concentration (ppb)

AsO4

3-

38 ppb P (Dodds, 1996) Clark Fork River target 7.8

7.5

pH

0

18:00 21:00 0:00 3:00 6:00

Time of Day

7.2

9:00 12:00 15:00 18:00 21:00 0:00

pH

Wenz, 2003

Redox cycling of phosphate?

PO4 fixed onto biofilms, sorbs onto Fe-oxides, calcite

PO4 released from respiration, bacterial reduction of Fe-oxides, etc...

sediment

sediment

Light-induced diurnal cycling of PO4 has been documented at lake/sediment interface (e.g., Carlton and Wetzel, 1988). A similar thing could happen in rivers.

Summary (emerging pattern...)

Nitrate, phosphate concentrations appear to go up at night, down during the day in streams that are far removed from any point-source nutrient loading Dramatic diurnal N-cycling may occur in hypereutrophic streams that become anoxic at night Mechanisms still unclear Very little published data.. need more case studies

Diurnal changes in dissolved organic carbon (DOC) in rivers

DOC is a key input parameter for the Biotic Ligand Model (BLM) DOC can complex metals DOC is a concern for chlorination of drinking water DOC catalyzes many photochemical reactions

Previous studies: DOC cycling

Kaplan and Bott (1982)

Dawson et al. (2001)

White Clay Creek, Pennsylvania Robust diurnal cycles in DOC (up to 40%), peaking during afternoon DOC flux controlled by balance between algal secretion and bacterial consumption

Spencer et al. (2007)

Acidic peat-land streams, Scotland No evidence of diurnal DOC cycling due to in-stream processes, despite fact that DOC is known to photo-degrade in low-pH waters Hypereutrophic San Joaquin River, CA Diurnal changes in DOC composition, but not in total DOC

concentration

Steve Parker et al. (MT Tech, in progress)

Underscores lack of knowledge of processes

Big Hole River, MT Large cycles in one summer, no cycles in next Behavior of DOC remains unexplained

Sources of data: nutrients

Babcock J. (in prep) Diurnal cycling of metals and nutrients in Silver Bow Creek, Montana. M.S. thesis, Montana Tech. Brick C. M. and Moore J. N. (1996) Diel variation of trace metals in the upper Clark Fork River, Montana. Envir. Sci. Technol. 30, 1953-1960. Carlton RG and Wetzel RG (1988) Phosphorus flux from lake sediments: Effect of epipelic algal oxygen production. Limnol. Oceanogr. 33, 562-570. Gammons C.H., T. M. Grant, D. A. Nimick, S. R. Parker, M. D. DeGrandpre (2007) Diel changes in water chemistry in an arsenic-rich stream and treatmentpond system. Science of the Total Environment 384, 433-451. Harrison JA, Matson PA, Fendorf SE (2005) Effects of a diel oxygen cycle on nitrogen transformations and green house gas emissions in a euthrophied subtropical stream. Aquat Sci 67:308-315

Laursen AE and Seitzinger SP (2005) Diurnal patterns of denitrification, oxygen consumption and nitrous oxide production in rivers measured at the whole-reach scale. Freshwater Biology 49, 1448-1458.

Scholefield D., Le Goff, T., Braven J., Ebdon L., Long T., and Butler M. (2005) Concerted diurnal patterns in riverine nutrient concentrations and physical conditions. Science of the Total Environment 344, 201-210. Wenz, A. (2003) Diurnal cycles in chemistry of the Big Hole River. M.S. thesis, Montana Tech.

Sources of data: DOC

Dawson JJC, Billett MF, Hope D (2001) Diurnal variations in the carbon chemistry of two acidic peatland streams in north-east Scotland. Freshwat Biol 46:1309-1322 Kaplan LA, Bott TL (1982) Diel fluctuations of DOC generated by algae in a Piedmont stream. Limnol Oceanogr 27:1091-1100

Manny BA, Wetzel RG (1973) Diurnal changes in dissolved organic and inorganic carbon and nitrogen in a hardwater stream. Freshwat Biol 3:31-43 Spencer RGM, Pellerin BA, Bergamaschi BA, Downing BD, Kraus TEC, Smart DR, Dahlgren RA, Hernes PJ (2007) Diurnal variability in riverine dissolved organic matter composition determined by in situ optical measurement in the San Joaquin River (California, USA). Hydrol Processes 21:3181-3189

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