I can understand you Muddassir, rejected articles looks very odd in our profile and dashboard. Even I feel very odd while looking at my rejected article in my contributions. But as other members already mentioned - articles can not be completely deleted from your profile and dashboard. So, there's no other solution to your problem then to tolerate them.
You must try hard to put your all efforts while writing articles so as the editors can approve them. And as your articles will get approved, the rejected articles in your profile will go to the next page of your contributions section which will not irritate you. So the conclusion for your problem is to write articles with good quality of English rather then posting articles which get rejected.
I find that the harder I work, the more luck I seem to have.