Henning, do you have any contacts at Chalmers or HFF? Signing up for a course there, or at Folkuniversitet if they have photo options, would be one way of getting supplies from the Nordic Laboratory suppliers.

Sulphuric Acid you can send down the drain, although in large amounts it can corrode some pipework or attack the caulking at junctions.

Potassium Dichromate you absolutely must not flush down the drain. Talk to whoever handles domestic waste in Göteborg to see how they recommend you drop it off to them once you have used it. Alternately, contact a skyddsombud at one of the educational institutions and see what they do. Here at Lund there is a central university disposal unit for such chemicals and I would be very surprised if Chalmers didn't have something similar. If you are only using small amounts they may let you piggy back off their system.

NaOH burns are worse than Sulphuric Acid ones, and strong alkalis will attack glass bottles (or weld the stopper on) faster than you think. On the other hand, Sulphuric acid is usually sold in concentrated form, and then you have the fumes and the hydrophilia to cope with. Not a big deal if you treat it with respect, but I wouldn't have it anywhere that young kids can get at.