(Original post by ScienceConfusion)
I know it's because it let's oxygen in and what not, but it's a past paper fourth year question worth 3 marks, can anyone give me a good answer? thank you so much, biology is not my strong point !!
I think it's because the bacteria that carry out the reaction (for forming NO3- ions), nitrifying bacteria, work best in aerobic conditions, where there is a plentiful supply of oxygen.