As previously mentioned on PPRuNe, the aircraft version of the "InSinkErator" is called the GWAD. Later aircraft are fitted with these devices and use the toilet vacuum system to get rid of the waste.
Unfortunately, the GWAD breaks down like any other form of galley equipment. The more complex something is, the more likely it is to break, especially if it is abused.
Re the fungus in the pipes... I wouldn't be surprised if milk and orange juice were the culprits. They curdle really well together... and you end up with something with the consistency (and perhaps the biodiversity) of yoghurt.
- As to the happy bacteria, products like 'DeStop' or 'Domestos' put an end to them in domestic drains. What is being used in aircraft systems?
White vinegar and ice are used for the toilets... I'm not sure what is used in the galley drains, if anything. Putting chlorine-based products in aircraft drains is probably not a very good idea.... it tends to corrode some of the more exotic metals used in aircraft construction
