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[Display omitted] • A new magnetic composite of FSNCS/SDBS was synthesized at low temperature. • FSNCS/SDBS shows excellent adsorption performance for CIP. • FSNCS/SDBS shows wide pH adaptability. • SDBS enhances CIP's adsorption by improving the surface charge of FSNCS. In this study, a novel magnetic nickel cobalt sulfide/sodium dodecyl benzene sulfonate (FSNCS/SDBS) adsorbent was synthesized successfully by a facile protocol and was developed to remove ciprofloxacin (CIP) for water purification. The FSNCS/SDBS adsorbent is featured with excellent CIP adsorption capacity of 625 mg·g−1 (much higher than reported most adsorbents), wide pH adaptability (little changed CIP adsorption capacity in pH 6–11), and good magnetic property. The effects of pH and ionic strength on CIP adsorption were investigated. The calculative thermodynamic parameters indicated that CIP adsorption by FSNCS/SDBS was spontaneous and exothermic. CIP adsorption followed pseudo-second-order kinetics and an isotherm best fit with the Langmuir adsorption mode. The adsorption mechanism of CIP onto FSNCS/SDBS was proposed and demonstrated, which included the electrostatic interaction, π–π interaction, coordination with metal and hydrogen bonding. [ABSTRACT FROM AUTHOR]

[Display omitted] • The synthesized adsorbents captured 94.18 mg g−1 of Co2+ and 62.56 mg g−1 of Ni2+. • <1% of lithium was lost in the cathode leachate during the separation process. • The dominant capture mechanism conversed from physical to chemical adsorption. • The N atoms on the adsorbents were the effective chemical adsorption sites. • Particle movement track in water was predictable via the proposed equation. The effectiveness of lithium recovery determines the future use of the devices powered by lithium-ion batteries (LIBs) under lithium resource shortages. Selective separation of Co2+/Ni2+ from the cathode leachate of LIBs is a key step to reduce the lithium loss in the recovery progress. This study reported a hollow structured self-floating adsorbent synthesized by co-grafting of (3-Aminopropyl)triethoxysilane (APTES) and ethylenediaminetetraacetic acid (EDTA) on hollow glass microsphere (HGM) for selective capture of Co2+/Ni2+ from LIBs cathode leachate. The introduction of the N atom of APTES was crucial for bridging the inorganic HGM and organic EDTA. The organic component of the synthesized adsorbent accounted for 12.82%, which was responsible for the Co2+/Ni2+ adsorptions. Physic- and chemic-adsorptions were the ordinal mechanisms during the three-stages divided adsorption progress. The negative –COO− groups promoted the electrostatic attraction between metal ions and the adsorbents. The N atoms of EDTA were the effective adsorption sites for Co2+ and Ni2+ ions, resulting in chemical chelation of the metal ions with adsorbents followed by ion exchanges of Na+ and Ca2+. The adsorbents captured 94.18 mg g−1 of Co2+ and 62.56 mg g−1 of Ni2+ with a < 1% lithium loss in the LIBs cathode leachate. The self-flotation process of the adsorbent was non-linearly fitted by our original equation for predicting its movement track for further solid–liquid separation. This research proposed a new strategy for the selective adsorption of Co2+/Ni2+ from LIBs cathode leachate with limited lithium loss. [ABSTRACT FROM AUTHOR]