Recent advances in adsorptive removal of wastewater pollutants by chemically modified metal oxides: A review

In addition to catalysis, drug delivery, and sensing, metal oxides can also be used as an adsorbent for wastewater treatment applications. In some of the cases, they need to be chemically modified to unlock their maximum potential. A change in composition could lead to the production of carbonaceous metal oxides, polymeric metal oxides, surfactant-supported metal oxides. Creating tailorable morphologies, high surface areas, and specific affinity for adsorption are the real motivations for the development of such materials for optimal results. Different analytical techniques namely atomic absorption spectroscopy (AAS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Inductively coupled plasma - optical emission spectrometry (ICP-OES), and Ultraviolet-visible spectroscopy (UV) have been utilized to uncover the mechanism underlying these reactions. A recent trend in this field is to develop new methodologies under differing experimental conditions. Metal oxides with chemically modified or supported surfaces are particularly important due to the substantial increase in practical applications. This review identifies the contributions towards synthesis, characterization, and applications of the latest developed chemically modified metal oxides (CMMOs). It also throws light on developing cost-cutting methodologies and in removing the toxic water pollutants using CMMOs as sorbents. The review also reveals the strong link between novel research in this area and available literature.

Automated summary

In addition to their common applications as catalysts, drug delivery systems, and sensors, metal oxides can also function as adsorbents in wastewater treatment. Chemical modification is often necessary to optimize their adsorption capabilities, leading to the production of carbonaceous metal oxides, polymeric metal oxides, and surfactant-supported metal oxides. Creating tailored morphologies, high surface areas, and specific affinity for adsorption are the main driving factors behind the development of such materials. Various analytical techniques have been used to investigate the mechanisms underlying these reactions. The development of chemically modified metal oxides with supported surfaces is of particular importance due to their increased practical applications.