4.1 Key findings
Dissolved oxygen: The amount of dissolved oxygen in Beakers A and C increased while the amount in Beaker B decreased. The amount in Beaker A increased the most.
pH level: The pH levels in all three beakers went from 6.35 to around 4.
Ammonium nitrogen: The amount of Ammonium Nitrogen in all three beakers decreased. The amount in Beaker A decreased the most.
Nitrate: The amount of nitrate in all three beakers increased. The amount in Beaker C increased the most while the amount in Beaker B increased the least.
Chloride: The amount of chloride in all three beakers decreased by around the same amount.
Calcium: The amount of calcium in Beakers A and C decreased while the amount in Beaker B remained around the same except that it increased slightly. The amount of calcium in Beaker A, containing Apple peel, decreased the most.
Turbidity: The turbidity in all three beakers increased.
4.2 Explanation of key findings
Ammonium nitrogen: Apple peel was most effective in removing ammonium nitrogen in the water.
Nitrate: Orange peel was the least effective in removing nitrate in the water.
Calcium: Apple peel was most effective in removing the metal, Calcium, in the water.
4.3 Evaluation of hypothesis
Our hypothesis was correct with the apple peel being the most effective in removing contaminants, especially the metal calcium.
4.4 Areas for improvement
We could have stored our experiment set-ups in the refrigerator to prevent mould from growing in our set-ups. This caused us to waste valuable time and we had to rush to redo the project again. We could also have widened the scope of our project, and not limit our experiment to just three fruits.