  We characterize spin wave propagation and its modification by an electrical
current in Permalloy(Py)/Pt bilayers with Py thickness between 4 and 20 nm.
First, we analyze the frequency non-reciprocity of surface spin waves and
extract from it the interfacial Dzyaloshinskii-Moriya interaction constant
$D_s$ accounting for an additional contribution due to asymmetric surface
anisotropies. Second, we measure the spin-wave relaxation rate and deduce from
it the Py/Pt spin mixing conductance $g^{\uparrow\downarrow}_{eff}$. Last,
applying a \textit{dc} electrical current, we extract the spin Hall
conductivity $\sigma_{SH}$ from the change of spin wave relaxation rate due to
the spin-Hall spin transfer torque. We obtain a consistent picture of the spin
wave propagation data for different film thicknesses using a single set of
parameters $D_s=0.25$ pJ/m, $g^{\uparrow\downarrow}_{eff} = 3.2\times 10^{19}$
m$^{-2}$ and $\sigma_{SH}=4\times10^{5}$ S/m.
