Magnetite a potential candidate in the removal of poisonous arsenic from drinking water: a comprehensive review

A significant concern regarding human health is the toxic substances present in water. The existence of arsenic contamination, in potable water, has been acknowledged as a significant global issue pertaining to human health. Numerous countries, including the USA, India, Bangladesh, Canada, Japan, Poland, Hungary, etc., face this issue regarding the percentage of arsenic being more than the acceptable limit in potable water as per United State Environmental Protection Agency (USEPA), which is 10 mu g/L. To get rid of this problem, various conventional technologies including precipitation, oxidation, adsorption etc., have been used, but unfortunately, most of these have been remained less effective due to their low efficiency to meet the requirement. In comparison to these traditional techniques, the other methods pertaining nanomaterials are found more promising due to available more surfaces to volume ration of the nanomaterials. In this regard, several nanomaterials have been studied; among these materials, magnetite (Fe3O4) is found as a potential candidate. The adsorbent Fe3O4 being magnetic in nature has great benefit from its separation point of view, since it can be isolated using an external magnetic field, while other nanomaterials face problems of separation after they are used as adsorbents. In order to realize the systems containing Fe3O4 nanomaterial as an adsorbent, it is essential to comprehend the entire process of arsenic adsorption by Fe3O4.Several matrices and surfaces have been used to coat the Fe3O4. In this review, at first, we aim to summarize the sources of arsenic, its harmful consequences on human health, and the technologies available for arsenic removal, which is accompanied by the detailed discussion of various methods and aspects of utilization of the Fe3O4 for removing arsenic from drinking water. In general, experimental conditions shows impact on efficiency; thus, this review also discusses the impact of various experimental conditions like pH, temperature, time, competing species concentration, adsorbent size, and doses on eradication of arsenic.