Management of internal nutrient reserves Jouni Lehtoranta Finnish - - PowerPoint PPT Presentation

▶
management of internal nutrient reserves
SMART_READER_LITE
LIVE PREVIEW

Management of internal nutrient reserves Jouni Lehtoranta Finnish - - PowerPoint PPT Presentation

Oct 06, 2023 109 likes •341 views

Management of internal nutrient reserves Jouni Lehtoranta Finnish Environment Institute Berlin 27.5.2019 Biogeochemical cycle Biogeochemical cycle Cycle where element or molecule is transferred between biotic and abiotic systems Reservoir

slide-1
SLIDE 1

Management of internal nutrient reserves

Jouni Lehtoranta Finnish Environment Institute

Berlin 27.5.2019

slide-2
SLIDE 2

Biogeochemical cycle

Biogeochemical cycle

Cycle where element or molecule is transferred between biotic and abiotic systems

Reservoir

Element stays very long in same place (apatite-deposit)

Exchange pool

Element is stored for a ”short” period of time Abiotic system forms commonly long term pools and exchange pools are formed by biota

Residence time

Period of time which element stays in one place

Abiotic environment Water = hydrosphere Earth’s crust = lithosphere Air = atmosphere

31.5.2019

slide-3
SLIDE 3

Phosphorus pools

slide-4
SLIDE 4

Reactions in water Reactions in sediment

Water Sediment

31.5.2019

PROBLEM IN THE BALTIC SEA

slide-5
SLIDE 5

INTERNAL PROBLEMS IN BALTIC SEA

  • Stratification properties of the Baltic Sea

– Sensitivity towards anoxia

  • High quantity of phosphorus in bottom

sediments

  • Poor natural ability of the sediment to retain

phosphorus permanently

slide-6
SLIDE 6

As a result in the Baltic Sea

Savchuk 2016

slide-7
SLIDE 7
  • First basin to achieve a status without eutrophication will

be Arkona, between 2030 and 2040

  • By 2060–2070, a status without eutrophication is

anticipated for the Kattegat, Bornholm Basin and Gulf of Finland,

  • The Danish straits around 2090
  • For the Baltic Proper and Bothnian Sea, a good status with

regard to eutrophication is not expected before 2200

  • Authors conclude that the basins Gulf of Riga and Bothnian

Bay are not likely to meet the targets agreed upon and to attain a status unaffected by eutrophication

slide-8
SLIDE 8

Human activities cause 70% of the loading

Proportion of background loading for phosphorus from Finland is 30%

Still great potential to eutrophy the Baltic Sea!

31.5.2019

slide-9
SLIDE 9

MANAGEMENT OF NUTRIENTS AND RISKS FOR ECOSYSTEMS

  • Case re-eutrophication of Lake Erie
  • Case artificial wetland in Finland
  • All present measures to reduce loading from

the diffuse sources

P

Phosphorus

30.974

Mn

Manganese

54,938

N

Nitrogen

14,007

slide-10
SLIDE 10

Internal measures are based on following mechanisms

  • Improve the geochemical conditions so that

nutrients are retained in bottom sediments

  • Remove the nutrients from the system
  • Add compounds which bind nutrients in the

system

slide-11
SLIDE 11

Experiments in the Baltic Sea

slide-12
SLIDE 12

Artificial oxygenation

to improve the geochemical conditions

Surface areas 0.5 km2 and 7 km2

Model MC 1100 (Water-Eco ltd)

  • Power 2.5 kW
  • Water discharge 87 000 m3/d
  • 800 kg O2/d
slide-13
SLIDE 13

Variation in oxygen, H2S, phosphate and total-P

3 10 15 19 2009 2010 2011

  • 40
  • 30
  • 25
  • 20
  • 15
  • 10
  • 5
  • 1

5 10 15

Oxygen & H2S (mg/L) 2009 2010 2011

  • 40
  • 30
  • 25
  • 20
  • 15
  • 10
  • 5
  • 1

5 10 15

Oxygen / H2S (mg/L) 8 16 24

Pumping area Reference basin

3 10 15 19 2009 2010 2011

10 50 100 200 300 400 500

PO4-P (µg/L) 3 10 15 19 2009 2010 2011

10 50 100 200 300 400 500

Tot-P (µg/L) 2009 2010 2011

10 50 100 200 300 400 500

PO4-P (µg/L) 8 16 24 2009 2010 2011

10 50 100 200 300 400 500

Tot-P (µg/L) 8 16 24

Lehtoranta et al. 2018

slide-14
SLIDE 14

Finland: Variation in oxygen and phoshorus

O2, mg/l

1.5 3 4.5 6 7.5 9 10.5 12 13.5 15 16.5 18

2006 2007 2008 2009 2010 2011 10 20 30 Depth (m) Float PO4, µg/l

20 40 60 80 120 160 200 240 280 320 360 400

2006 2007 2008 2009 2010 2011 10 20 30 Depth (m) Float

Lehtoranta et al. 2018

slide-15
SLIDE 15

Compound additions

to improve the binding ability

  • On fields gypsum, structure lime
  • On sediments

– Aluminium compounds – Iron compounds – Phoslock, lanthanum (LaPO4) – Marl – Zeolite/hydrous zirconia (Fan et al. 2017, Wat. Res.)

slide-16
SLIDE 16

Rydin and Gumblad 2019 Capturing past eutrophication in coastal sediments – Towards water-quality goals

Alum additions Björnöfjärden

  • Treated area 0.73 km2
slide-17
SLIDE 17

Additions of marl

  • First pilot experiments with residue marl from

pile in Gotland will be carried out in Östergötland, Stockholm

  • The suitability of local limestone residues in

Parainen will be studied for piloting in the Archipelago Sea of Finland

slide-18
SLIDE 18

Removal of bottom sediment

Dredging test for underwater units showing that they are capable of retrieving a top layer of sediment from seabed, down to 120 meters water depth.

Seabased project: Pilot experiment in the Archipelago Sea Finland Semienclosed bay 0.01 km2 with reference area

slide-19
SLIDE 19

Technology readiness level (TRL)

slide-20
SLIDE 20

Photo: Ilkka Heikkinen, Inkoo

Thank you

31.5.2019

slide-21
SLIDE 21

Definition

  • Ecological engineering
  • Seabased measures
  • Management of internal nutrient reserves