A reusable Fe3O4/GO-COOH nanoadsorbent for Ca2+ and Cu2+ removal from oilfield wastewater

Magnetic silica/graphene oxide nanocomposite supported ionic liquid-manganese complex as a powerful catalyst for the synthesis of tetrahydrobenzopyrans

A novel magnetic silica/graphene oxide nanocomposite supported ionic liquid/manganese complex (Fe3O4@SiO2-NH2/GO/IL-Mn) is prepared, characterized and its catalytic application is investigated. The Fe3O4@SiO2-NH2/GO/IL-Mn catalyst was synthesized via chemical immobilization of graphene oxide on Fe3O4@SiO2 nanoparticles followed by modification with ionic liquid/Mn complex. This nanocomposite was characterized by using SEM, TGA, FT-IR, PXRD, EDX, TEM, nitrogen adsorption-desorption, and VSM analyses. The catalytic application of Fe3O4@SiO2-NH2/GO/IL-Mn was studied in the synthesis of tetrahydrobenzo[b]pyrans (THBPs) in water solvent at RT. This nanocatalyst was successfully recovered and reused at least eight times without a significant decrease in its activity.

Technological trends in nanosilica synthesis and utilization in advanced treatment of water and wastewater

Water and wastewater treatment applications stand to benefit immensely from the design and development of new materials based on silica nanoparticles and their derivatives. Nanosilica possesses unique properties, including low toxicity, chemical inertness, and excellent biocompatibility, and can be developed from a variety of sustainable precursor materials. Herein, we provide an account of the recent advances in the synthesis and utilization of nanosilica for wastewater treatment. This review covers key physicochemical aspects of several nanosilica materials and a variety of nanotechnology-enabled wastewater treatment techniques such as adsorption, separation membranes, and antimicrobial applications. It also discusses the prospective design and tuning options for nanosilica production, such as size control, morphological tuning, and surface functionalization. Informative discussions on nanosilica production from agricultural wastes have been offered, with a focus on the synthesis methodologies and pretreatment requirements for biomass precursors. The characterization of the different physicochemical features of nanosilica materials using critical surface analysis methods is discussed. Bio-hybrid nanosilica materials have also been highlighted to emphasize the critical relevance of environmental sustainability in wastewater treatment. To guarantee the thoroughness of the review, insights into nanosilica regeneration and reuse are provided. Overall, it is envisaged that this work's insights and views will inspire unique and efficient nanosilica material design and development with robust properties for water and wastewater treatment applications.

Nanotechnology in Wastewater Management: A New Paradigm Towards Wastewater Treatment

Clean and safe water is a fundamental human need for multi-faceted development of society and a thriving economy. Brisk rises in populations, expanding industrialization, urbanization and extensive agriculture practices have resulted in the generation of wastewater which have not only made the water dirty or polluted, but also deadly. Millions of people die every year due to diseases communicated through consumption of water contaminated by deleterious pathogens. Although various methods for wastewater treatment have been explored in the last few decades but their use is restrained by many limitations including use of chemicals, formation of disinfection by-products (DBPs), time consumption and expensiveness. Nanotechnology, manipulation of matter at a molecular or an atomic level to craft new structures, devices and systems having superior electronic, optical, magnetic, conductive and mechanical properties, is emerging as a promising technology, which has demonstrated remarkable feats in various fields including wastewater treatment. Nanomaterials encompass a high surface to volume ratio, a high sensitivity and reactivity, a high adsorption capacity, and ease of functionalization which makes them suitable for application in wastewater treatment. In this article we have reviewed the techniques being developed for wastewater treatment using nanotechnology based on adsorption and biosorption, nanofiltration, photocatalysis, disinfection and sensing technology. Furthermore, this review also highlights the fate of the nanomaterials in wastewater treatment as well as risks associated with their use.