Accelerating Dechlorination Using Calcium Oxide with the Assistance of Metallic Aluminum in Mechanochemical Reaction

An innovative additive, CaO-Al is utilized for the mechanochemical degradation (MCD) of chlorinated persistent organic pollutants (Cl-POPs). The introduction of Al into CaO significantly accelerates the reaction by promoting the release of electrons. The degradation efficiency of hexachlorobenzene (HCBz), 2,2-bis(4-chlorophenyl)-1,1-dichloroethane (P.P′-DDD), and γ-hexachlorocyclohexane (γ-HCH) reaches 99.70, 97.75, and 99.71%, respectively, after 3, 1.5, and 8 h of milling. The stability of these organics in MCD follows the sequence of γ-HCH > HCBz > P.P′-DDD, which is consistent with their degree of unsaturation.