Attapulgite supported nanoscale zero-valent iron in wastewater treatment and groundwater remediation: synthesis, application, performance and limitation

ABSTRACT Polluted water continues to be a major problem globally since it deteriorates human health after consumption and impedes sustainable development. Nanoscale zero-valent iron (nZVI) has been used to tackle the problem, but certain significant disadvantages of the nZVI limit its efficiency. Owing to the demerits of nZVI, various materials have been employed to support the nZVI to ensure efficient decontamination. There is rising interest in using attapulgite as a support for nZVI. The use of attapulgite supported nanoscale zero-valent iron (A-nZVI) to decontaminate wastewater/groundwater has proven to be highly efficient as compared to unsupported nZVI. This paper presents an overview of the syntheses, performance, application and limitations of using A-nZVI to treat wastewater/remediate groundwater. A-nZVI has been extensively employed on laboratory scale, thus making it difficult to simulate its removal efficiency on a large scale. However, its high removal efficiency under the appropriate operational conditions make it ideal to be used on an industrial level. This review is important because it identifies gaps in literature with respect to A-nZVI that need to be filled to improve ZVI-based technology. GRAPHICAL ABSTRACT