Recent advances on sustainable adsorbents for the remediation of noxious pollutants from water and wastewater: A critical review

This review article evaluates and compares the efficiency of various sustainable adsorbents for the removal of noxious pollutants from water environments. This study discusses the various types of adsorbents concerning their performance and suitability. Adsorbent types include natural-based, carbon-based, waste-based, biomass-based, biopolymers-based, and nanocomposites-based adsorbents, as well as metallic organic frameworks, aerogels, networking crystalline solids, zeolite nanoparticles, and dendrimers were reviewed. Characterisation, modification, fabrication, adsorption capacities under different conditions, isotherm models, and kinetics of noxious pollutants were also reviewed. Adsorption capacities for different pH values, adsorbent doses, adsorbent concentrations, temperature, and the size of particles have been described. One of the basic needs in water and wastewater adsorbents is their formulation and optimisation, using columnar operations, and more importantly, they can be produced quickly and should be cost-effective. Various studies reported a broad range of values for the thermodynamic parameters for noxious pollutants, suggesting the adsorbent's nature as an essential factor affecting the thermodynamics of noxious pollutant sorption. The regeneration and reusability potential of other adsorbents have also been discussed, along with molecular modelling, simulation, knowledge gaps, and future perspectives of noxious pollutants from the water environments.