This document discusses various types of water pollution including organic and inorganic pollutants, thermal pollution, and invasive species. It describes how pollution can influence biological systems and identifies common pollutants like nutrients, toxic metals, and pathogens. The text also discusses indicators of pollution like biochemical oxygen demand and biotic indices, and consequences of pollution like eutrophication and dead zones forming from lack of oxygen. Finally, it recommends various water management strategies to reduce pollution and restore ecosystems.

1. WATER POLLUTION

3. • What is a Pollutant?
– Is a waste material which pollutes air, water or soil
– The terms “pollutant” and “contaminant” more or less
synonymous.
– Pollutants may be in the form of
• organic or inorganic substances ,
• light,
• sound
• thermal energy
• biological agents
• invasive species and
• wide range of human activities including the combustion of
fossil fuels.
– Pollutants may be Primary (active on emission) or
secondary (arising from primary pollutants undergoing
physical or chemical change)

4. • WATER POLLUTION
• groundwater & surface water
• influence human and other biological systems.
• KNOWLEDGE & UNDERSTANDING:
– sources.
• variety of freshwater & marine pollution
– Types of aquatic pollutants
• floating debris,
• organic material,
• inorganic plant nutrient (nitrates & phosphates),
• toxic metals,
• synthetic compounds,
• suspended solids,
• hot water,
• oil,
• radioactive pollution,
• pathogens,
• light,
• noise & biological pollutants (invasive spp).

5. – Biodegradation of organic material
• utilizes oxygen, lead to anaerobic decomposition,
• in turn leads to formation of methane, H2S and ammonia (toxic
gases).
– BOD (Biochemical Oxygen Demand)
• is a measure of the amount of dissolved oxygen required to
break down the organic material in a given volume of water
through aerobic biological activity.
• used to indirectly measure the amount of organic matter within
a sample.
– Indicator Spp.:
• Some species can be indicative of polluted waters and can be
used as indicator spp.
– A biotic index indirectly measures pollution
• by assaying the impact on spp within the community according
to their tolerance, diversity and relative abundance.

6. – Eutrophication
• Lakes, estuaries, coastal waters
• receive inputs of nutrients (nitrates & phosphates), which
results in an excess growth of plants and phytoplanktons.
– Dead zones
• Oceans & fresh water
• when there is not enough O2 to support marine life.
– Water management strategies
• Reducing human activities that produce pollutants
– ex alternatives to current fertilizers & detergents
• Reducing release of pollution into the environment
– ex treatment of waste water to remove nitrates and phosphates
• Removing pollutants from the environment & restoring
ecosystems
– ex removal of mud from eutrophic lakes & reintroduction of plant
& fish spp.

7. • GUIDANCE
– Sources of freshwater pollution
• include runoff, sewage, industrial discharge and solid domestic waste.
– Sources of marine pollution
• include rivers, pipelines, atmosphere and activities at sea (operational
and accidental discharges).
– The role of positive and negative feedback in the process of
eutrophication .
• Coastal eutrophication can lead to red tide blooms.
• INTERNATIONAL MINDNESS
– Countries with limited access to clean water often have
higher incidences of water illnesses.
• TOK
– A wide range of parameters are used to test the quality of
water and judgments are made about causes and effects of
water quality- how can we effectively identify cause-effect
relationships, given that we can only ever observe
correlation?

8. • CANCER VILLAGES
-village of Xiditou, SE of Beijing, the
cancer rate is 30 times the national average.
-because of water and air pollution by
chemical factories.