Partial degradation of carbofuran by natural pyrite

•Carbofuran (2,2-dimethyl-2,3-dihydrobenzofuran-7-al-methylcarbamate) was partially degraded by natural pyrite.•Degradative pathways of carbofuran were suggested.•Pyrite showed a potential as a geo-catalyst in pollution control.

This work provides new insight into the degradation of 2,2-dimethyl-2,3-dihydrobenzofuran-7-yl-methylcarbamate (hereafter carbofuran) by natural pyrite as a function of pH and adsorbent loading. In the presence of tert-butyl alcohol i.e., OH scavenger, the degradation efficiency of carbofuran was almost stopped. In acidic solutions (pH < 5) the degradation kinetics was pseudo first order in carbofuran as −d[carbofuran]dt=−kobserved×[carbofuran]. The dependence of kobserved on [FeS2] was given as kobserved = k0 + [FeS2] × k1 where k0 = 1.16 × 10−7 h−1 and k1 = 0.137 h−1. The elucidation of precise steps of carbofuran degradation by pyrite has yet to be solved.

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