Abstract
Wastewater containing methanesulfonic acid (MSA) mainly originates from the production process of metal detergent, contributing to significant environmental pollution. This study explores the use of trioctylamine (TOA) to extract MSA from wastewater. Various factors affecting the extraction efficiency, including the extractant type, phase ratio (O/A), diluent, temperature, stirring speed, and extraction time were systematically investigated. An extraction efficiency of 96.1% was achieved using TOA (0.86 mol·L− 1) at 25°C, 1400 r·min− 1, and an extraction time of 30 minutes. FT-IR, XPS, and high-resolution ESI-MS analyses provided insights into the extraction mechanism, revealing that the complexation between TOA and MSA occurs through ionic and hydrogen bonding interactions. Additionally, TOA was successfully regenerated through back-extraction with sodium hydroxide. The proposed extraction system is advantageous for eco-friendly engineering applications.