Question

Denitrification of wastewater can be obtained through autotrophic biological reactions.

a. Write a balanced equation for denitrification of NO3 _ to N2 using S2O3 -2 (which oxidize to SO4 -2 ) using fs (max) and assuming the bacteria use ammonia as a nitrogen source for cell synthesis.

b. B. How many grams of Na2S2O3 would need to be added to the wastewater per gram of NO3 - reduced?

Answer 1

a) Reduction half reaction 2N03 (aq)+11H+ (aq)-10e-→X,(g)-6H2O(1) Oxidation half reaction Overall reaction 5s.oç (aq) +25H,0 10SOÇ (aq) +50H.(aq)+40e 8NQUaq)-ss,ος (aq)-H-0(l) 4X,(g) +10SOÇ (aq) + 2H+ (aq) 1.0g 6 b)Moles of Ma in 1.0 g = 62g /mol = 0.0161mol NO 5mol Na,S,o 38mol NO Moles of Na,S,O 0.0161mol NOÇx 0.01 01mol 158.11g Na.S,O lmol Na,S,O Mass of Na,SO 0.0101mol Na,S.0,x 1.60 g