Removal of mercury from solutions of mercuric nitrate by mercuric sulfide

The removal of mercury from dilute solutions of mercuric nitrate by mercuric sulfide is indicative of an adsorption process. The relation of log $\text{x}\text{m}$ vs. log C shows that the Freundlich adsorption isotherm exists.At higher concentrations of mercuric nitrate a reaction takes place with the mercuric sulfide forming a compound of the possible formula 2HgS·Hg(NO₃)₂ mercuric nitratodisulfide.