A zero-dimensional model which includes 56 species of reactants and 427 reactions is used to study the behavior of charged particles in atmospheric plasmas with different ionization degrees at low altitude (near 0 km).The constant coefficient nonlinear equations are solved by using the Quasi-steady-state approximation method.The electron lifetimes are obtained for afterglow plasma with different initial values,and the temporal evolutions of the main charged species are presented,which are dominant in reaction processes.The results show that the electron number density decays quickly.The lifetimes of electrons are shortened by about two orders with increasing ionization degree.Electrons then attach to neutral particles and produce negative ions.When the initial electron densities are in the range of 1010～1014cm3,the negative ions have sufficiently high densities and long lifetimes for air purification,disinfection and sterilization.Electrons,O2,O4,CO4 and CO3 are the dominant negative species when the initial electron density ne0≤1013cm3,and only electrons and CO3 are left when ne0≥1015cm3.N+2,N+4 and O+2 are dominant in the positive charges for any ionization degree.Other positive species,such as O+4,N+3,NO+,NO+2,Ar+2 and H3O+ · H2O,are dominant only for a certain ionization degree and in a certain period.
