Superadsorbent Ni–Co–S/SDS Nanocomposites for Ultrahigh Removal of Cationic, Anionic Organic Dyes and Toxic Metal Ions: Kinetics, Isotherm and Adsorption Mechanism

Abstract

Novel adsorbent Ni–Co–S/SDS (nickel cobalt sulfide/sodium dodecyl sulfate) nanocomposites have been synthesized by a simple and eco-friendly approach using water as a solvent at low temperature. The prepared nanocomposites structure and morphology were studied by powder XRD, SEM, TEM, XPS, FT-IR, TGA, and also the surface area and surface charge of the adsorbents were measured by BET and ζ-potential. These nanocomposites showed an excellent adsorption property for both cationic {crystal violet (CV), rhodamine B (RhB), methylene blue (MB), Nile blue A (NB)}, anionic {methyl orange (MO) and Congo red (CR)} organic dyes and Cr­(VI) metal ions. They exhibited maximum adsorption capacity 3598.23 mg g–1 for CR, 3284.08 mg g–1 for MO, 4417.79 mg g–1 for NB, 3598.23 mg g–1 for CV, 1451.64 mg g–1 for MB, 773.47 mg g–1 for RhB and 583.67 mg g–1 for Cr­(VI) ions respectively, which are higher adsorption capacities than reported and exhibited an efficient adsorption property for both cationic and anionic dyes. Furthermore, nanocomposites showed adsorption efficiencies greater than 95% after regenerated and reused up to five times. Moreover, it followed pseudo-second-order kinetics and an isotherm best fit with the modified Zhu and Gu model. Based on the adsorption studies, FT-IR and ζ-potential measurements studies confirm that the hydrogen bonding and electrostatic interactions are the predominating factors for first step adsorption process and second step is hydrophobic interaction between adsorbates. Overall, remarkable adsorption capacity and reusability of Ni–Co–S/SDS nanocomposites elucidate the scope as an environmental remedy for industrial applications.

Green Tea Waste as an Efficient Adsorbent for Methylene Blue: Structuring of a Novel Adsorbent Using Full Factorial Design

“…Various organic contaminants exist in the environment. As per the World Bank report, dyes are major contributors to water pollution [3,4]. Dyes can reach the water systems via different routes, e.g., from paper, textile, cosmetics, leather, plastics, and foodstuff industries.…”

“…Approximately 5% of tanning wastes end up as effluents that are usually discarded into lakes, rivers, and ponds. Being colored and possessing variable chemical structures and different physicochemical properties, dyes represent a real burden on the ecosystem [3][4][5][6][7][8][9][10][11].…”

Polytorsional-amide/carboxylates-directed Cd(ii) coordination polymers exhibiting multi-functional sensing behaviors

“…With the rapid development of industrialization and agriculture in the world, more and more wastewater is discharged without rational treatment, causing heavy metal and organic pollution in the ecological environment. [1][2][3][4] Common heavy metal elements include Fe, Cr, Mn, etc. 5,6 Iron is an essential trace element for the human body, but excessive intake will endanger health, and because of its long-lasting toxicity, it will lead to metabolic disorder and increase the risk of cardiovascular disease and cancer.…”

A Sharp Jump in Photocatalytic Activity of Elemental Sulfur for Dye Degradation in Alkaline Solution

“…Thus, these pollutants must be removed from the water (1). Several methods have been reported for the removal of dyes from wastewater such as adsorption (2)(3)(4)(5)(6)(7)(8)(9)(10)(11), membrane filtration (12,13), oxidation (14), coagulation-flocculation (15), and photocatalytic process (16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28). Each of these methods has their advantages and disadvantages.…”