By a special representation of the number density operator and working
with a modulus-phase formalism we obtain the dissipative current, needed
to ensure particle number (or charge) conservation in the conducting system
coupled to an environment. This generalizes and simplifies previous derivations
aimed at the Lindblad type of master equations. In addition to a part
depending linearly on the Hamiltonian current, we obtain also a pseudo-curl
contribution to the dissipative current.
