The Separation of Phosphate and Arsenate from Seawater by Adsorption Colloid Flotation

Procedures are described whereby phosphate and arsenate in seawater are brought to the surface in less than 5 min by an adsorption colloid flotation process which uses a positively charged iron(III) hydroxide collector, an anionic surfactant, sodium dodecyl sulfate, and nitrogen. Statistical studies on test series show a mean recovery of 90.7 % with a relative standard deviation of 3.1 % for phosphate at the 3.0 μg-at./l level, a mean recovery of 91.2% with a relative standard deviation of 1.5% for arsenate at the 3.0 μ-at./l level, and a mean recovery of 94.1% with a relative standard deviation of 0.8 % for the combined 0.30 μg-at. AsO4 3−−As/l and 2.25 μg-at. PO4 3−−P/1 samples.