Skip to content
English

Galium

Gallium
6:07

Gallium (Ga)

1. Basic Information

Atomic Number 31
Symbol Ga
Atomic Weight 69.723 g/mol
Electron Configuration [Ar] 3d¹⁰ 4s² 4p¹

2. Physical and Chemical Properties

Gallium is a post-transition metal with a low melting point (29.8°C), making it liquid at temperatures slightly above room temperature. In the solid state, gallium is bluish gray or shiny silver. Gallium is soft and can be cut with a knife. Chemically, gallium is relatively stable in air and water, but soluble in strong acids and bases. Gallium has the unique property that it can wet the surface of glass and porcelain, forming an excellent reflective layer. It also readily forms alloys with most other metals.

3. Presence in Water and Health Effects

Gallium is rarely found in its pure form in nature. Its concentration in natural water is usually very low. Although it has no known biological role in the human body, gallium is found in small amounts (about 0.7 mg in a 70 kg human body). In small amounts, gallium is not harmful to humans. However, exposure to certain gallium compounds such as gallium(III) chloride may cause throat irritation, breathing difficulties, and in severe cases may cause pulmonary edema.

4. Water Treatment Applications and Removal Methods

Although gallium is rarely a major contaminant in water treatment, several methods can be used to remove it if needed: 1. Ion Exchange: Ion exchange resins can be used to remove gallium ions from water. Weak acid cation resins or strong acid cation resins are effective for removing gallium in cation form. 2. Adsorption: Adsorbents such as activated carbon or activated alumina can remove gallium from water. 3. Chemical Precipitation: Under proper pH conditions, gallium can be precipitated as hydroxide or other salts. 4. Membrane Filtration: Membrane technologies such as nanofiltration or reverse osmosis can effectively remove gallium ions. 5. Electrocoagulation: This technique can be used to remove gallium and other heavy metals from wastewater.

5. Industrial Use in Water Treatment

Gallium itself is rarely used directly in water treatment. However, some gallium compounds have specific applications in water analysis and water quality monitoring.

6. Case Studies and Real-World Application Examples

A study in China examined gallium removal from semiconductor industry wastewater using an electrocoagulation process. Results showed removal efficiencies of up to 99% at optimal conditions. This study demonstrated the potential of electrocoagulation as an effective method for gallium removal from industrial wastewater. In the mining industry, particularly in bauxite processing, gallium is often a by-product. Some processing facilities have developed systems to recover gallium from their process water, improving resource efficiency and reducing the potential for environmental contamination.

7. Regulatory Guidelines and Standards

Currently, there are no specific standards for gallium in drinking water set by WHO or the US EPA. However, some countries have guidelines for gallium concentration in industrial wastewater. For example, China has set a maximum limit of 1 mg/L for gallium in wastewater from the semiconductor industry.

8. Environmental Impact and Sustainability Considerations

Although gallium is not considered highly toxic to the environment, its accumulation in aquatic ecosystems can have long-term effects that are not yet fully understood. The increasing use of gallium in the electronics and renewable energy industries raises concerns about its potential release into the environment. From a sustainability perspective, recovery and recycling of gallium from wastewater and used electronic products is becoming increasingly important. This not only reduces the environmental impact but also secures the supply of this rare metal for high-tech applications.

9. Future Trends and Research in Water Treatment

Current research focuses on developing more efficient and environmentally friendly methods to remove and recover gallium from water: 1. Nanomaterials: Development of nanoparticles specifically designed for selective adsorption of gallium from water. 2. Biosorption: Use of microorganisms or plant biomass to remove gallium from wastewater. 3. Advanced Membrane Technology: Development of new membranes with high selectivity for gallium. 4. Solid Phase Extraction: Research on new and more efficient resins for gallium recovery. 5. Integrated Approach: Combining various technologies for more comprehensive and efficient water treatment.

10. Interesting Facts Related to Water Treatment

1. Gallium has a very low melting point (29.8°C) that allows it to liquefy in the hand, but a very high boiling point (2204°C), giving it an unusually wide liquid phase range. 2. Although rare in natural water, gallium can accumulate in wastewater from the semiconductor and solar cell industries, creating unique challenges and opportunities in water treatment. 3. Gallium nitrate has been used in medicine to reduce excessive blood calcium (hypercalcemia), demonstrating the potential for complex interactions between gallium and other minerals in biological systems. 4. In water treatment, the chemical behavior of gallium can change significantly depending on pH and the presence of other ligands, requiring a flexible approach in its removal strategy. 5. Recovery of gallium from wastewater is not only important for environmental protection but also of high economic value due to the scarcity and growing demand for this metal in high-tech industries.
,