  We present an x-ray diffraction study of the Vanadium-doped blue bronze
K0.3(Mo0.972V0.028)O3. At low temperature, we have observed both an intensity
asymmetry of the +-2kF satellite reflections relative to the pure compound, and
a profile asymmetry of each satellite reflections. We show that the profile
asymmetry is due to Friedel oscillation around the V substituant and that the
intensity asymmetry is related to the charge density wave (CDW) pinning. These
two effects, intensity and profile asymmetries, gives for the first time access
to the local properties of CDW in disordered systems, including the pinning and
even the phase shift of FOs.
