Recent application of nanotechnology in environmental remediation

Abstract

Recently, environmental pollution is a great concern in both developing and developed countries. Rapid unplanned urbanization, industrialization, overpopulation growth, and intensive agricultural activities cause contamination of water, and soil notably. Major pollutants include heavy metals, metalloids, dyes, natural organic matters, chlorinated organic compounds, organophosphorus compounds, volatile organic compounds, and halogenated herbicides. Acute pollution may cause long-term damage to the environment, if not controlled at the right time. Therefore, promising methods for pollutant remediation are urgently needed. Nanotechnology has potential applications in many fields and it is the next industrial revolution (IR). The application of nanotechnology in pollution control and environmental remediation has gained popularity over the last decade. Nanotechnology helps in the development of remediation technologies that are specific and efficient for a particular pollutant. Thus, nanotechnology provides a sustainable solution to the global challenges of protecting water, and soil. Nanomaterials have a high adsorption capacity for pollutants because of their large specific surface area (SSA), a large number of active surface sites, and a good affinity to other species. This study mainly highlights the various nanomaterials used in environmental remediation. The study also aims to provide comprehensive information relating to the recent progress in the development of nanomaterials and nanocomposites for environmental remediation. The work further deals with the different aspects of nanotechnology in water, and soil contamination and presents the recent advances with a focus on a sustainable solution for environmental remediation in an eco-friendly approach. The societal impact that nanotechnology has on the environment has been discussed. The potential research gaps, prospective, challenges, and limitations in this field have been also identified. It is noted that nanomaterials such as metal oxides, carbonaceous nanomaterials, polymeric materials, natural materials, and agriculturally derived low-cost adsorbents are commonly used in environmental remediation as adsorbents, catalysts, photocatalysts, membrane (filtration), disinfectants, and sensors. Carbonaceous materials have been commonly used in the removal of organic and inorganic contaminants from water. Nanoscale zero-valent iron is used for soil remediation. New environmental remediation technologies are constantly being explored, and recent studies have focused on developing new environmental remediation technologies using various nanomaterials. All experiments related to pollutant removal have been carried out in batch or column method. Only a few studies dealt with real wastewater. Green synthesis of nanomaterials needs to be adopted because not all nanomaterials are produced in an eco-friendly way. Proactive nano-waste management strategies need to be adopted and nano-waste should be recycled. The development of biodegradable nanomaterials focusing on new functional materials, processing technology, and cost reduction needs to be considered for commercial application. This study helps to understand the potential of nanotechnology in resolving the growing problem of environmental contamination. However, more extensive research and development into the promising application of nanotechnology are highly warranted.