“…The sorption of hydrogen sulfide on anion-exchange resins in the OH-form follows the mechanism of the usual neutralization reaction [17]. The sulfide form thus formed can additionally absorb an equimolar amount of H 2 S [40,64]: 44) Weakly basic anion-exchangers under dynamic conditions practically do not absorb hydrogen sulfide, because its aqueous solution is a too weak acid (pK a1 = 7.02, pK a2 = 12.20 ÷ 15.00 at 25 °C [65]), so only strongly basic anion-exchangers are used. Hydrogen sulfide also be sorbed with strongly basic and weakly basic cation-exchangers in salt form with 3d metals (for example, Cu 2+ , Ni 2+ , Co 2+ , Cd 2+ , Zn 2+ ) [66], forming with it sparingly soluble sulfides, firmly held by the spatial matrix of chemisorbent:…”