A comprehensive review on the sequestration of dyes from aqueous media using maize-/corn-based adsorbents

Abstract

Corn or maize (Zea mays L.) is the most significant grain crop worldwide after wheat and rice. It is widely cultivated and consumed as food, feed, and industrial raw material, along with the emission of a large quantity of corn waste. Such abundant, renewable, and cheap wastes with unique chemical compositions can be efficiently converted into adsorbents for the elimination of dye-contaminated water. This article represents an extensive review of the use of corn/maize waste-derived adsorbents for the sequestration of dyes from aqueous media. This study addressed the utilization of corn residues, including cob, stalk, straw, husk, and silk, as precursors for adsorbents. The adsorption behaviour, mechanism, and regeneration of the studied corn adsorbent/dye systems were identified. It was observed that the most common forms of corn/maize-derived adsorbents that have been utilized for the sequestration of dyes include biosorbents, biochars, activated carbons, and composites. The highest adsorption capacity (1,682.7 mg/g) for dye (methylene blue) sequestration was obtained using a corn husk composite-based adsorbent. Important findings and future ideas are finally mentioned for the corn/maize-based materials and their application as adsorbents for dye removal. HIGHLIGHTS Use of corn adsorbents strengthens the popular waste-to-wealth management strategy.; The adsorbent groups include biosorbents, activated carbons, biochar, and composites.; Major mechanisms are electrostatic attraction, ion exchange, and hydrogen bonding.; The adsorbents can be recycled and reused several times.; The highest adsorption capacity (1,682.7 mg/g) was obtained using a corn husk-based composite.;

Keywords

• adsorption
• composite adsorbent
• corn cob
• dyes
• environment