Information Extraction/Semantic Search for long, unstructured documents
If you think filtering certain POS-tag words or "bad" topics from topic modelling doesn't suffice to distinguish between relevant text and junk, you can implement your custom filter. Try regex rules and use your prodigy licence to annotate junk to fit a classifier based on tf-idf or other text feature extractor.

But don't forget, there isn't a preprocessing framework that fits all needs.