Aims of the session:
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Learn about fertilisers and their effects on the environment.
Be able to answer exam questions on the effects.
Learn about Pesticides and their effects
Summarise the key points about pesticides
Fertilisers and Pesticides
Fertilisers
s e wa g e
(l i q u i d d o m e s t i c
a n d i n d u s t ri a l w a s t e )
m i n e ra l s
e s p . n i t ra t e s
m i n e ra l s
e s p . p h o s p h a te s
e u t ro p h i ca t i o n
a lg a l b lo o m
or
ganic m
at
er ial
The process of
Eutrophication
f e rt i l i s e rs
c o m p e titio n
fo r lig h t
c o n s u m e rs c a n ' t
c o n s u m e fa s t e n o u g h
d e a d p la n ts
d e a d a lg a e
d e t ri t u s
fo r lig h t
c o n s u m e fa s t e n o u g h
The process of Eutrophication cont.
d e a d p la n ts
d e a d a lg a e
d e t ri t u s
m o re d e c o m p o s e rs
use up oxygen
b y a e ro b i c re s p i ra t i o n
(i n c re a s e d B O D )
a e ro b e s d i e
(i n v e rt e b ra t e s ,
a n a e ro b i c b a c t e ri a
t h ri v e . R e l e a s e
Biochemical Oxygen Demand (BOD).
This measures the rate of oxygen consumption by a
sample of water, and therefore gives a good
indication of eutrophication. A high BOD means lots
of organic material and aerobic microbes, i.e.
eutrophication
The nitrate concentration falls during spring and
summer and rises during autumn and winter
Less algal growth as autumn begins
Possibly all plants have died
Pesticides
Pesticides
Include:
• Herbicides
• Insecticides
• Fungicides
• Bactericides
Pesticides
Persistence
= Bioacculmulation
+ Lipid solubility
Bioaccumulation
E.g DDT
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