A review of the new multifunctional nano zero-valent iron composites for wastewater treatment: Emergence, preparation, optimization and mechanism. (December 2021)

• Record Type: Journal Article
• Authors: Wang, Peng; Fu, Fugang; Liu, Tingyi
• Is Part Of: Chemosphere. Volume 285(2021)
• Publication Date: 2021-12
• Subjects: Multifunctional NZVI-Composites -- Preparation technologies -- Optimization technologies -- Mechanism; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.131435
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Nano zero-valent iron (NZVI) with high chemical reactivity and environmental friendliness had recently become one of the most efficient technologies for wastewater restoration. However, the unitary NZVI system had not met practical requirements for wastewater treatments. Expectantly, the development of NZVI would prefer multifunctional NZVI-based composites, which could be prepared and optimized by the combined methods and technologies. Consequently, a systematic and comprehensive summary from the perspective of multifunctional NZVI-composite had been conducted. The results demonstrated that the advantages of various systems were integrated by multifunctional NZVI-composite systems with a more significant performance of pollutant removal than those of the bare NZVI and its composites. Simultaneously, characteristics of the product prepared by the incorporation of numerous methods were superior to those by a simple method, resulting in the increase of the entirety efficiency. By comparison with other preparation methods, the ball milling method with higher production and field application potential was worthy of attention. After combining multiple technologies, the effect of NZVI and its composite systems could be dramatically strengthened. Preparation technology parameters and treatment effect of contaminants could be further optimized using more comprehensive experimental designs and mathematical models. The mechanism of the multifunctional NZVI system for contaminants treatment was primarily focused on adsorption, oxidation, reduction and co-precipitation. Multiple techniques were combined to enhance the dispersion, alleviating passivation, accelerating electron transfer efficiency or mass transfer action for optimizing the effect of NZVI composites. Graphical abstract: Image 1 Highlights: The advantages of different simple systems are combined by multifunctional NZVI composites. Better results can be achieved by combining multiple preparation methods. More attention should be paid to the ball milling method. The objective problems of NZVI composites are improved by multi-technologies assisted and more comprehensive models. The mechanism of multifunctional NZVI composites is based on adsorption, oxidation, reduction and co-precipitation.