Recovery of Indium from Etching Wastewater using Supported Liquid Membrane with Strip Dispersion with Vegetable Oil as Diluent

Supported Liquid Membrane with Strip Dispersion (SLMSD) is an effective and cost-efficient method for recovering precious metals. Traditionally, petroleum-based diluents such as kerosene or Isopar-L are employed; however, their use raises environmental and safety concerns. This study investigates sunflower oil, a green and renewable alternative, as a diluent in SLMSD for recovering In³? from etching waste solution. Results indicate effective Indium recovery using 0.4 M D2EHPA as the extractant with the permeability of In³? was 9.5 × 10?6 m.min-1. A model-based estimation suggests that 99 % removal of In³? could be achieved within 1.22 h using a 1.4 m² membrane. This highlights vegetable oil’s potential as a sustainable diluent in SLMSD applications.