An integrated approach for soluble and insoluble pollutants: Surface performance regulation of Co2CO3(OH)2@Ni foam for effective ciprofloxacin removal and oil/water separation

Abstract

Effectively removing both soluble antibiotics and insoluble oils from wastewater is a significant challenge. To address both the problems, we synthesized a three-dimensional (3D) porous water treatment material. It can be converted from antibiotic removal mode to oil removal mode by simple surface performance regulation. This approach achieved a high removal rate for ciprofloxacin (CIP) and good separation efficiency for oil/water mixtures. Initially, Co2CO3(OH)2 nano-needles were fixed on Ni foam to synthesize Co2CO3(OH)2@Ni foam-1, which had a high CIP removal rate (93.59 % at pH 7.0) and a certain anti-interference ability. To assess the CIP removal performance, the environmental impact, economic benefit and energy consumption (3E) triangle model was established and the optimal operating point was selected. Characterization experiments demonstrated that the removal of CIP was attributed to the mechanisms of surface complexation, electrostatic attraction, cation bridging, precipitation and flocculation. Subsequently, Co2CO3(OH)2@Ni foam-2 was obtained by hydrophobic modification, which exhibited separation efficiencies above 93.5 % for a series of different oil/water mixtures. Co2CO3(OH)2@Ni foam series materials are easy to prepare and possess effective pollutants treatment efficiency, thus providing a new strategy for developing multi-functional water treatment materials and a novel approach for the treatment of soluble antibiotics and insoluble oils in wastewater.