Question

Write the balanced chemical reaction for the following nitrogen cycle reactions. These reactions are mediated by bacteria and plants in nature and in wastewater treatment. (a) nitrification of ammonium to nitrite using molecular oxygen. (b) nitrification of nitrite to nitrate using molecular oxygen. (c) denitrification of nitrate to N2 using succinic acid as the carbon

Answer 1

Answer:

Nitrification is a biological process by which ammonia is oxidized to nitrites ($NO_{2} ^{-}$) and then to nitrates ($NO_{3} ^{-}$) by action of specialized bacteria in nature (such as nitrosomonas and nitrobacter).

Explanation:

This two-step process utilizes molecular atmospheric oxygen and ammonia and ammonium components of soil and nature.

(a.) Ammonia and ammonium compounds to nitrite

$NH_{4} ^{+} + O_{2}$ → $NO_{2} ^{-} + 4H^{+}$

$2NH_{3} ^{+} + 3O_{2}$ → $2NO_{2} ^{-} + 2H^{+} + 2H_{2} O$

(b.) Nitrite to nitrate

$2NO_{2} ^{-} + O_{2}$ → $2NO_{3} ^{-} + energy$

(c.) The reverse process involves reduction of nitrates to molecular nitrogen, called denitrification (with succinic acid in the equation below).

$4NO_{3} ^{-} + 10H^{+} + (CH_{2})_{2}(COOH)_{2}$ → $2N_{2} +4CO_{2} + 8 H_{2} O$

($NO$ and $N_{2}O$ is an intermediate product in this process.)