Separation of Cadmium (II) Ions from Aqueous Solutions using Cyanex 921-Based Extraction System
Year: 2026
Type: book-chapter
Abstract: Cadmium (Cd) is a highly toxic heavy metal released into the environment through industrial activities such as electroplating, battery manufacturing, pigments, and alloy production. Due to its persistence and harmful effects on human health and ecosystems, the removal of Cd(II) ions from aqueous solutions is an important environmental challenge. This chapter focuses on the separation of Cd(II) ions using a Cyanex 921-based extraction system. Cyanex 921 (tri-n-octylphosphine oxide, TOPO) is a neutral organophosphorus extractant known for its strong solvating ability, high chemical stability, and strong affinity toward metal ions in chloride media. The extraction mechanism involves the formation of stable solvated complexes such as CdCl₂·2L in the organic phase. Key parameters affecting extraction efficiency, including acidity, chloride concentration, extractant concentration, temperature, and phase ratio, are discussed. Under optimized conditions, Cyanex 921 can achieve extraction efficiencies greater than 99% with high selectivity for Cd(II), making it an effective method for wastewater treatment and metal recovery.
Authors: Rohit Kumar, Jugpal Singh, Pragya Pali
Institution: IFTM University
Language: English
Subfield: Metals and Alloys
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7154682913