Green synthesis of sunlight active rice husk biochar loaded with metal ferrite nanocomposite for efficient removal of pesticides: kinetics and photoactivity

Because of their incorrect disposal, persistent characteristics, endocrine disrupting, and genotoxic, two pesticides, Lindane and 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (DDE), pose serious health concerns. Given its cost-effectiveness and environmental benignity, photocatalysis is considered a promising methodology to remove pesticides using nanomaterials from wastewater. Here, biochar (BC)-loaded CoFe2O4 (BC@ CoFe2O4) was synthesized for the sequential photocatalytic degradation of Endosulfan (ES) and 4,4-DDD pesticides. The waste of agricultural products, i.e., rice husk, has been utilized to prepare BC. The structural and microscopic studies that validated the semi-crystalline behavior of BC@CoFe2O4 decrease due to the addition of BC (amorphous). The optimal conditions for the maximum elimination of toxic Lindane (95%) and DDE (91%) by BC@ CoFe2O4 were identified at a catalyst loading of 20 mg, neutral pH level, and an initial pollutant concentration (10 mg L-1). The degradation mechanism comprises initial Langmuir adsorption followed by first-order kinetics. The identification of diverse radical quenchers has suggested a substantial involvement of hydroxyl radicals in breaking down Lindane and DDE. The nanocomposite has exhibited exceptional sustainability and cost-efficiency, retaining its efficacy over six cycles with negligible activity decline. Due to its advantageous surface properties, BC@CoFe2O4 nanocomposite shows immense potential as a peculiar and remarkable photocatalyst for various industrial uses.