摒除 is formal/literary and applies mostly to abstract things - prejudices, distracting thoughts, doubts, bad habits. For physical removal use 排除 or 清除. The character 摒 carries 扌 (hand) plus 屏 (screen out), giving the image of pushing something away.
mistakes
Don't confuse with 屏除 - same meaning, different first character (no 扌). Both are correct; 摒除 is more common today.
