A wastewater has been characterized for nitrogen-containing compounds and the total nitrogen was 26 mg N/L, the total kjeldahl nitrogen was 14 mg N/L, and the nitrate was 27.3 mg N03-/L. What is the potential theoretical oxygen demand (mg O2/L) associated with nitrogen species in the wastewater. My teacher said there should be a way to relate all of these together to find the answer, but I cannot figure out their relationship.