Removal of Cadmium, Zinc, and Manganese from Dilute Aqueous Solutions by Foam Separation

As environmental regulations are becoming stricter, new techniques must be developed for the removal of trace concentrations heavy metals from mineral processing effluents. Foam separation an interesting alternative to more conventional processes such as ion exchange because their efficiency treat dilute aqueous streams. In this paper, simultaneous Cd2+, Mn2+, and Zn2+ solutions was investigated by using sodium dodecyl sulfate collector triethylenetetramine auxiliary ligand via a series batch-mode flotation experiments. Experimental results showed that can completely removed in one step under following conditions: pH 9.50, time = 120 min, concentration 0.1 mmol L?1, collector-to-metals molar ratio 2:1, ethanol 0.5% (v/v), nitrogen gas flowrate set at 25 mL min?1. An excess yielded low efficiency. The modeled speciation examined system suggested separated bulk solution foam phase combination precipitate flotation.