I found this question that describes PCB etching with citric acid. The answer to that question explains how hydrogen peroxide, salt, and citric acid can be used to ionize copper metal in water, which provides:
$$\ce{Cu + H2O2 + 2 H+ -> Cu^{2+} + 2 H2O}$$
The equation above excludes the citrate ion, so maybe it isn't party to the reaction. This observation prompted the following:
Question:
- Assuming the citric acid ion is $\ce{C6H7O7^-}$, what is the equation for the neutralization reaction (I kept $\ce{H^+}$ in this, but it's been a while since highschool/college chem, this may not be represented right):
$$\ce{Cu^{2+} + C6H7O7^- + H^+ + Na2CO3 -> } ??? $$
- What remains ionized in solution after neutralizing with $\ce{Na2CO3}$?
- Will there be a precipitate? If so, what?
(This will inform our choices for responsible disposal. I'm not sure what other details to provide, as this seems like a pretty simple question. Let me know if you need more information.)