  We study quasilinear parabolic stochastic partial differential equations with
general multiplicative noise on a bounded domain in $\mathbb{R}^{d}$, with
homogeneous Dirichlet boundary condition. We establish the existence and
uniqueness of solutions in a $L^{1}$ setting, and we prove a comparison result
and an $L^{1}$-contraction property for the solutions. In addition, we show the
existence of an invariant measure in case of non-degenerate diffusion. Finally,
we show the uniqueness and ergodicity of the invariant measure in $L^{1}$, in
case of bounded diffusion and additive noise.
