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Describe the process of eutrophication, and assess the suitability of water quality tests used to monitor it. - HSC - SSCE Chemistry - Question 26 - 2003 - Paper 1
Question 26
Describe the process of eutrophication, and assess the suitability of water quality tests used to monitor it.
Worked Solution & Example Answer:Describe the process of eutrophication, and assess the suitability of water quality tests used to monitor it. - HSC - SSCE Chemistry - Question 26 - 2003 - Paper 1
Step 1
Describe the process of eutrophication
Answer
Eutrophication is a process that occurs when water bodies, such as lakes or rivers, become overly enriched with nutrients, primarily nitrogen and phosphorus. This nutrient enrichment can come from various sources, including agricultural runoff, sewage discharge, and industrial waste. As nutrient levels rise, aquatic plants, particularly phytoplankton, proliferate excessively, leading to algal blooms.
These algal blooms can reduce water clarity and, upon decay, deplete dissolved oxygen in the water, creating hypoxic or anoxic conditions that can be detrimental to aquatic life. Fish and other organisms may die as a result, disrupting the ecosystem.
In summary, the key stages of eutrophication are nutrient enrichment, algal bloom growth, oxygen depletion, and the ecological consequences of these changes.
Step 2
Assess the suitability of water quality tests used to monitor it
Answer
To monitor eutrophication, several water quality tests are commonly employed, including tests for Biochemical Oxygen Demand (BOD), Dissolved Oxygen (DO), nitrates, and phosphates.
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BOD is a measure of the amount of oxygen consumed by microorganisms in a water sample, which can indicate the organic matter presence often associated with eutrophication. High BOD values suggest organic pollution, a potential symptom of eutrophication.
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DO levels are critical for assessing water quality as they indicate whether aquatic life can survive. Low DO levels, often resulting from algal decay, highlight the negative impact of eutrophication on ecosystems.
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Nitrates and phosphates are direct indicators of nutrient pollution. Elevated levels of these compounds signal eutrophication risk and allow for proactive measures to be taken to address nutrient inputs.
In conclusion, the combination of these tests provides a comprehensive overview of water quality related to eutrophication, and they are suitable for monitoring its effects. However, it is essential to consider the timing and frequency of these tests to obtain accurate assessments of changes in water quality.