Ultrahigh adsorption by regenerable iron-cobalt core-shell nanospheres and their synergetic effect on nanohybrid membranes for removal of malachite green dye

The accelerated use of an industrial dye (malachite green (MG)) has led to serious deterioration of water bodies. Although, several water treatment methods have been investigated for MG removal, but they are either costly or produce several byproducts. To address these issues, the present research demonstrates the application of reusable iron-cobalt (Fe-Co) core-shell nanospheres against MG removal from water, using batch adsorption and membrane filtration technique. During batch adsorption, almost complete MG removal (99.8%) was observed against significantly high dye concentration (150 ppm) and the maximum adsorption capacity achieved was 270.27 mg g−1. Furthermore, the adsorbent exhibited excellent reusability up to five consecutive cycles. For membrane filtration studies, remarkable MG dye removal efficiency (97%) was achieved through M-0.1 membrane (containing 0.1% Fe-Co loading) along with outstanding water flux rate (214.73 L/m2 h). Additionally, a multi-cycle filtration test for M-0.1 membrane demonstrated high stability in MG dye separation performance and permeate flux throughout three consecutive cycles. All findings confirm the outstanding potential and financial feasibility of Fe-Co nanospheres in the removal of MG dye for both batch adsorption as well as membrane filtration processes.