Sciencemadness Discussion Board

How to deal with waste?

JDMonster - 13-10-2019 at 18:43

Hey guys, I am currently studying Chemical Engineering at my university and I've been wanting to do my own reactions and extractions on the side when I'm on break. How do you guys deal with waste considering that subscriptions to companies are quite expensive?

JDMonster - 13-10-2019 at 19:14

Sadly my University runs a very tight ship when it comes to waste, so dumping it off there isn't an option.

Sulaiman - 13-10-2019 at 19:20

There are many threads on this topic here on SM,
the general principles are;

. choose reaction paths that use the least toxic reactants and produce the least toxic products

. use minimum quantities required to get the desired result

. research your reactants and products - dealing with waste should be obvious based on this knowledge

acids, bases, oxidants and reductants can be neutralised

things such as heavy metals;
convert to insoluble salts, dry, mix into small concrete blocks for disposal.

solvents should ideally be recovered for further use by distillation etc.

For each planned experiment you can ask here on SM for specific advice.

Herr Haber - 14-10-2019 at 03:23

- Buy ice cream
- Eat the ice cream
- Clean the ice cream boxes
- Buy concrete
- DO NOT EAT THE CONCRETE.

But I'm sure from there you'll figure it out :)

There's also the option of dîsposing of your (solid) waste by putting it in a sealed container and then filling said container with expansive foam.
Keep in mind one of the properties of expansive foam is that... it expands ! And if you empty the canister and then remove the plastic straw... oh boy...

subsecret - 29-10-2019 at 07:26

Most non-chlorinated solvents can be burned safely. You might be able to deal with chlorinated materials by heating with sodium hydroxide so they're no longer chlorinated, and then burning.

For inorganics, the concrete blocks are a good idea. Make sure you keep your metal waste containers alkaline so nothing's soluble. Note: long-term storage in 5-gal buckets isn't a good idea and will likely leak. :o

teodor - 29-10-2019 at 07:58

Quote: Originally posted by subsecret  
Make sure you keep your metal waste containers alkaline so nothing's soluble.


Hm, some of metals/nearly metals ions (Pb, As) dissolve in alkaline solutions pretty well. For that reason I add sodium polysulfide solution to my Pb waste. PbS is insoluble, this way I can handle it safely.

[Edited on 29-10-2019 by teodor]