Gallium (Ga) and water

Gallium (Ga) and water: occurrence, chemistry and removal

Gallium is a trace element associated mainly with aluminium- and zinc-bearing ores and is used in semiconductors. Dissolved concentrations in natural waters are usually very low, but mining, acid drainage and industrial process waters can create local exceptions. Gallium’s water chemistry changes with pH and ligands, so treatment needs to be designed for the actual process stream.

Illustrative semiconductor production, industrial water treatment and sample glassware; not a measured sample or a gallium-specific test. — Illustration of semiconductor process water and treatment; it does not represent measured gallium concentrations.

How does gallium enter water?

Gallium substitutes for aluminium or zinc in several minerals and is recovered mainly as a by-product of alumina or zinc processing. Most weathering releases little dissolved gallium because many gallium-bearing phases have low solubility; it can travel with fine particles. Acidic drainage from sulfide-rich mine waste may mobilize more gallium. Industrial wastewater from semiconductor manufacturing or alumina refining can contain higher concentrations than natural waters. A USGS review reports dissolved and colloidal gallium above 10 µg/L in groundwater near semiconductor manufacturing areas in China; this is a site-specific observation, not a general groundwater value.

Gallium chemistry in water

Gallium commonly occurs as Ga(III), and its behaviour resembles aluminium in many natural waters. Hydrolysis and the formation of hydroxide complexes vary with pH; sulfate, chloride, fluoride and organic ligands can also affect speciation. Gallium is often associated with suspended or settled solids in streams, but acidic or strongly alkaline industrial liquors can keep different gallium species in solution. Total and dissolved measurements may therefore differ substantially.

How can gallium be removed or recovered?

In mine drainage, neutralization and clarification may reduce dissolved gallium through precipitation or sorption onto iron- and aluminium-rich solids. The result depends on pH, ligands and the composition of the solids, and the resulting sludge must be managed. For concentrated industrial liquors, studies have investigated ion exchange, solvent extraction and other separation methods to recover gallium. Semiconductor wastewater can also contain gallium arsenide, so any recovery or treatment scheme must assess and manage arsenic as well. These specialized recovery processes are not equivalent to a validated drinking-water treatment design.

For process evaluation, characterize total and dissolved gallium, pH, alkalinity, aluminium, zinc, sulfate, chloride, fluoride, arsenic where relevant, and suspended solids. Read more about ion exchange and elements and their interaction with water.

Last reviewed: 31 October 2026 by Lenntech.