Lithium (Li) in Water Treatment

Quick Answer

Lithium (Li) is an alkali metal with atomic number 3. PubChem lists its standard state as solid and its relative atomic mass as 7.0.

Lithium can occur naturally in groundwater and in mining or battery-industry wastewater. Conventional filtration does little for dissolved Li+; selective ion exchange, nanofiltration, reverse osmosis or recovery processes may be considered after laboratory testing.

Interesting Facts

• Lithium is the lightest metal, but Li⁺ is strongly hydrated in water—one reason selective separation from sodium and magnesium can be difficult.
• Brines can be both a water-treatment challenge and a lithium resource, so a project may optimise recovery rather than simple disposal.
• A particle filter cannot capture dissolved Li⁺; process claims should be tested in the real ionic matrix, especially at high salinity.

Water-treatment Design Implications

An element name alone is not enough to select treatment equipment. Confirm chemical form or speciation, total and dissolved concentration, pH, alkalinity, competing ions and the product-water target. Send the water-analysis results to Watermart to identify additional testing and shortlist processes before equipment is specified.

Summary Data Sources

• PubChem — Lithium
• IUPAC Periodic Table of Elements
• WHO chemical hazards in drinking-water

1. Basic Information

Atomic Number	3
Symbol	Li
Atomic weight	6.941 g/mol
Electron configuration	[He]2s1
Year of discovery	1817

2. Physical and Chemical Properties

• Lithium is a soft, silvery-white alkali metal with a low melting point.
• It has high thermal conductivity and low viscosity.
• Reacts strongly with water to form lithium hydroxide and flammable hydrogen gas.
• Reactive with nitrogen, oxygen, and water vapor in the air, forming lithium hydroxide, lithium nitrate, and lithium carbonate on its surface.

3. Presence in Water and Health Effects

• Lithium is present in small amounts in natural waters due to weathering of rocks and minerals.
• Natural concentration varies strongly with geology. A medicinal lithium dose is not a drinking-water benchmark, and hazards of lithium metal or concentrated industrial chemicals should not be confused with dilute Li⁺ in water.

4. Water Treatment Applications and Removal Methods

• Strong-acid cation resin can exchange Li⁺, but it generally prefers many competing divalent ions; capacity and early lithium breakthrough must be tested in the actual water.
• Selective sorbents, membranes, electrodialysis and recovery processes are available for different matrices. No single “only” method applies to all lithium waters.

5. Industrial Use in Water Treatment

• Lithium has limited applications directly in water treatment other than removal by ion exchangers.
• Some lithium compounds such as lithium chloride and lithium bromide are used in air conditioning systems to absorb moisture.

6. Case Study or Real World Application Example

• Lithium purification from brine for production of lithium carbonate and lithium hydroxide for lithium batteries.
• Lithium removal from lithium battery industry wastewater using ion exchange, precipitation, and electrodialysis methods.

8. Environmental Impact and Sustainability Considerations

• The extraction of lithium from brine and other mineral deposits can have environmental impacts due to water consumption and waste disposal.
• The increasing demand for lithium batteries is driving the development of more sustainable lithium recycling technologies.