Science Buddies: "Ask an Expert"

How do you dispose of Colbalt Nitrate as well as Phosphate Buffer?

This will depend on the laws prevailing where you live. Contact your locality's waste collection service for information on chemical waste disposal. Another possibility is to ask if you can add your waste to the waste at your school's chemistry lab. Good luck!

Cobalt Nitrate is toxic and bad for the environment. Phosphate buffer not so toxic, but still bad for the environment. So you'd want to dispose of them following the toxic waste disposal process in your town. Your garbage company probably knows how to do this.