Yes it is possible! You can do it a couple of ways:
You can have various blogs under one WordPress install which each use different categories. So for example, you have 3 blogs, each uses it’s own template containing a loop which shows only posts from its corresponding category. So a blog about dogs only shows posts in the category ‘dogs’, the blog about bears only shows posts with category ‘bears’, and so on. When you write the posts you simply check the category you want the post to be in and it’s then only shown on that blog’s page.
Another way is to use separate installs: http://codex.wordpress.org/Installing_Multiple_Blogs
Hope that helps!