Cu and Zn in Dutch surface waters

Cu and Zn in Dutch surface waters
options to reduce emissions from (agricultural) soils
Luc Bonten, Bert Jan Groenenberg, Paul Römkens
Cu and Zn in Dutch surface waters
current total concentrations in surface waters
copper (Cu), ● > 3.8 μg/l
zinc (Zn), ● > 40 μg/l
Problem
Soil as a source of heavy metals?
x kg/yr
? kg/yr
metals
metals
fodder and
additives
antropogenic sources
manure
fertilizer
atmospheric
deposition
hoof
desinfectants
sorbed metals
metals in soil
solution/
groundwater
metals in soil
minerals
geogenic sources
leaching to
groundwater
systems
other sources
Historic sources of soil inputs
copper
zinc
Metal leaching and run-off
Metal leaching and run-off depends on:
 land-use
 geology
 soil properties
 meteorology/hydrology
 history
National leaching assesment requires regional scale model
calculations
Model
uptake by
crops
metal inputs
background
metal
contents
geostatistical
model
transport within soil profile
metals in
soil
leaching to
surface
water
metals in
solution
chemical
equilibrium model
mass transport
model
soil property
map
hydrological
model
Model results
(leaching and run-off to surface waters)
copper
zinc
Sources of metals in surface waters
Case study: Keersop catchment
Model calculations Keersop catchment
 250 x 250 grid
 soil profile till 13 m depth
 starting in 1880 with geogenic background
concentrations of Zn and Cd
 soil loads based on production data and process
information
Zn loads to soil in Keersop catchment
3 sources:
 atmosferic deposition
 leaching from pavements with zinc smelter slags
 agriculture (manure and fertilizer)
deposition
10
smelter slags
agriculture
8
6
4
2
year
2000
1990
1980
1970
1960
1950
1940
1930
1920
1910
1900
0
1890
Zn loads to soil (kg/ha/yr)
12
Concentrations in soil and surface water
Measures to reduce soil loads
4 scenarios:
•
•
•
•
current loads are continued
less manure (stricter regulations for N and P)
50% less Cu and Zn in fodder
no Cu from hoof desinfectants
Scenarios: leaching
copper
zinc
Scenarios: Cu soil balance
current loads
reduced manure
... + fodder
... + desinfectants
Scenarios: Zn soil balance
current loads
reduced manure
... + fodder
Metals in groundwater:
natural background vs. current
high concentrations in south of Netherlands:
•
•
Kempen area (Cd en Zn)
pyrite oxidation
Pyrite oxidation
oxidation of pyrite, especially in sandy soils
FeS2 (pyrite)
Zn
Cu
Cd Ni
NO3
N2
Fe3+ + SO42- + Metals
Summary

Cu and Zn in Dutch surface waters > water quality criteria

leaching and run-off contribute much to total emissions to surface waters

main inputs to soil are Cu and Zn in fodder and hoof desinfectants

reducing Cu in Zn fodder and hoof desinfectants 
only stand-still of emissions and soil balances

pyrite oxidation by nitrate additional sources of metal emissions
Thank you for
your attention!