Development of a Technology for Treating Wastewater Contaminated with Nitric Acid

Table 1

Rate terms used in the mass balance equations^a.

Components (𝑖)	Evaporation rate	Mass transfer rate	Reaction rate
NH3	𝐾𝑣𝑖(𝑝𝑖−𝑝𝑦𝑖)	kla(𝑐eq−𝑐)	−𝑘𝑐NH3𝑐HNO3
HNO3	𝐾𝑣𝑖(𝑝𝑖−𝑝𝑦𝑖)	—	−𝑘𝑐NH3𝑐HNO3
NH4NO3	—	—	𝑘𝑐NH3𝑐HNO3
H2O	𝐾𝑣𝑖(𝑝𝑖−𝑝𝑦𝑖)	—	—

aNote: 𝑘_𝑣𝑖 and 𝑝_𝑖 are the evaporation rate constant (mol h⁻¹) and the equilibrium pressure (atm) of components (𝑖), 𝑝𝑦_𝑖 is the vapor pressure represented by the molar fraction of vapor (atm), kla is the volumetric coefficient of mass transfer (h⁻¹), and 𝑘 represents the kinetic constant (mol⁻¹ L h⁻¹).