We present the results of an optical and X-ray monitoring campaign on the short-period massive SB2 binary HD 152218 .
Combining our HiRes spectroscopic data with previous observations , we unveil the contradictions between the published orbital solutions .
In particular , we solve the aliasing on the period and derive a value close to 5.604 d. Our eccentricity e = 0.259 \pm 0.006 is slightly lower than previously admitted .
We show that HD 152218 is probably undergoing a relatively rapid apsidal motion of about 3 ^ { \circ } yr ^ { -1 } and we confirm the O9IV+O9.7V classification .
We derive minimal masses of 15.82 \pm 0.26 M _ { \odot } and 12.00 \pm 0.19 M _ { \odot } and constrain the radius of the components to R _ { 1 } = 10.3 \pm 1.3 R _ { \odot } and R _ { 2 } = 7.8 \pm 1.7 R _ { \odot } .
We also report the results of a XMM -Newton monitoring of the HD 152218 X-ray emission throughout its orbital motion .
The averaged X-ray spectrum is relatively soft and it is well reproduced by a 2-T optically thin thermal plasma model with component temperatures about 0.3 and 0.7 keV .
The system presents an increase of its X-ray flux by about 30 % near apastron compared to periastron , which is interpreted as the signature of an ongoing wind-wind interaction process occurring within the wind acceleration region .