A river is subject to seasonal pollution by fruit canning factories which are active between June and September every year. A survey carried out on two different days to investigate the flow of water in the river and the nitrate concentrations at a point downstream of the factories gave the following results:

Day 1
Discharge: 5.3 m³/s
NO₃⁻: 0.29 mg/L

Day 2
Discharge: 2.2 m³/s
NO₃⁻: 0.83 mg/L

Calculate how much nitrogen (N) is flowing down the river on each occasion (kg N/s). Which is the higher value and why?