Rapid removal of organic pollutants by a novel persulfate/brochantite system: Mechanism and implication

Using natural minerals as persulfate activators can develop effective and economical in situ chemical oxidation technology for environmental remediation. Yet, few natural minerals can provide a high activation efficiency. Here, we demonstrate that brochantite (Cu₄SO₄(OH)₆), a natural mineral, can be used as a persulfate activator for the rapid degradation of tetracycline hydrochloride (TC-H). Approximately 70% of TC-H was removed in Cu₄SO₄(OH)₆/PDS within 5 min, which much higher than that of Cu₃P (61.99%), CuO (29.75%), CNT (25.83%), Fe₂O₃, (14.48%) and MnO₂ (9.76%). Experiments and theoretical calculations suggested that surface copper acts as active sites induce the production of free radicals. The synergistic effect of Cu/S promotes the cycle between Cu⁺/Cu²⁺. Sulfate radicals and hydroxyl radicals are the main reactive oxygen species that are responsible for the rapid removal of TC-H. The findings of this work show a novel persulfate/brochantite system and provide useful information for the environmental remediation.