I have a Canon sx520 hs. I wanted to know whether I can use lens filters like a UV protector or the one that blurs the background?
I wanted to know whether I can use lens filters like a UV protector
Yes. A $20 adapter is available that lets you attach 67mm filters to this camera.
or the one that blurs the background?
You can blur the background without a filter. Your camera has a max aperture of f/3.4 at the wide end, and that should be wide enough to get some bokeh especially if you can put some distance between the subject and the background. Practice shooting in aperture priority (Av) mode so that you can set the aperture yourself, and go for the largest aperture (i.e. smallest f-number) you can at the focal length you're using.
First, I advise, never mount an optical filter unless the good outweighs the bad. All digital cameras have a UV filter incorporated in cover glass that protects the image sensor. All modern color films have a UV absorbing layer atop. That being said, the UV filter is the most popular, its primary good is to protect the camera lens from scratches and abrasions.
Black & white film does not always reproduce color as we would expect. Red, often reproduce too dark and puffy white clouds don’t stand out against a blue sky background. We all had a gadget bag filled with filters to enhance. Color film slide and movie film also benefit from the correction filters we carried. Not entirely true for color negative film, we could filter the camera but more often we filtered during the printing stage.
Digital photography is another story. Most of the time we need not filter because we can apply all these techniques and more with simple computer editing.
What are the down sides to optical filters? These filters must be optical flats, if not they induce distortion. It is more difficult to make and optical flat than to make a lens.
What filters should you chose for the digital camera? The most valuable filter is the polarizing screen. It also acts like a UV to cut haze. Next is a granulated neutral density filter. Next is a strong neutral density to allow super slow shutter speeds under bright light conditions. The UV filter is super useful for aerial photography at high altitude and for haze cutting when imaging distant mountain vistas. The UV fails when imaging nearby subjects.
You can mount any filter – all you need do figure out how to mount them. You can even use duct tape to help you mount them.