I got a first in geology in 1986, and my PhD in 1991, in theoretical geochemistry and mass spectrometry from U of London. After I qualified, I have mainly worked in industry, in civil site investigation, in mass spectrometry, the chemicals industry. Now, after 20 years of being a water and environmental hygiene specialist, in the built environment, I want to go back to research or a meaningful post that perhaps uses my commercial experience.

What are my chances of getting a postdoc or a job in a university these days? in Scotland in particular, but I am willing to consider relocation; China seems to want plenty of skilled academics these days.

I have loads of commercial experience, and still have enthusiasm for teaching and learning.

Where are the jobs advertised?

Hard to say. I know some older postdocs that I assume have transferred recently back into academia, but I'm not sure of their background or their past experience that qualified them for the post. Make some applications and find out? They often only ask for a CV and cover letter so they are not too arduous.

Jobs.ac.uk is the best place for UK academic jobs.

Yes agree about jobs.ac.uk (despite the name, they advertise international jobs), and the New Scientist job search is usually good. Maybe a subject-specific publication in your field might advertise relevant opportunities. Or look at university websites, including individual research group's pages.

I don't know how your age would affect things exactly - I think your experience would be in your favour, compared with younger applicants who maybe `only' have the experience of their PhD, although if you don't have a recent publication record that could be an obstacle in applying for a research post. Depends on the role and the institution though (it might matter less for a more teaching-focused position).

It seems like you have nothing to lose by applying. Good luck!