Water Treatment

Thanks for the information on how water treatment plants operate. I 
would, however, like to point out several factual errors in your post.

Phosphate and nitrate cant be oxidized out of the water ... they are 
already oxidized. Dont you mean to say the organic compounds to which 
they are attached are being oxidized?

Phosphate doesnt hold ferric iron in solution. It forms complex 
oxyhydroxide colloids which eventually precipitate into the substrate.

When you oxidized organic phosporus you dont get rid of the P ... it is 
still in solution as an inorganic salt.

Macronutrients are generally thought of as N, P, K, S, Ca, Mg (and of 
course C, O, H). This is a term of convenience, however, there is no 
functional difference between a macro- and micro-nutrient.

NO3 is not the most reduced form of N ... in fact it is the most 
oxidized form.

Algae outcompete higher plants for nutrients because they have more 
sensitive and efficient uptake enzymes.

Proteins and urea do NOT  contain phosphate in any amount.

A saturated fertile substrate is anaerobic and acts to; solubilize iron by 
reducing it from ferric (rust) to ferrous iron, solubilize phosphate, and 
convert NO3 to NH3 which is a preferred form of N for many aquatic plants.
The chief benefits of the substrate are therefore not the CEC but its 
anaerobic state.

Dr. dave