| Technology |
Advantages |
Disadvantages |
| Coagulation/precipitation: calcium hydroxide; aluminum hydroxide
|
High efficiency; commercially available chemical |
Expensive, efficiency depends of pH and presence of co-ions in water, adjustment and readjustment of pH is required, elevated residual aluminum concentration, formation of sludge with high amount of toxic aluminum fluoride complex and high amount of retained water (sludge dewatering is required prior disposal) |
| Membrane filtration: reverse osmosis; nanofiltration
|
High efficiency; remove other contaminates |
High capital high running and maintenance costs toxic waste water produced |
| Electrochemical treatments: dialysis; electro-dialysis; electro-coagulation
|
High efficiency; high selectivity |
High cost during installation and maintenance |
| Ion-exchange: Strong basic anion-exchange resin with quaternary ammonium functional groups
|
High efficiency |
Expensive, vulnerable to interfering ions (sulfate, phosphate, chloride, bicarbonate, etc.), replacement of media after multiple regenerations, used media present toxic solid waste, regeneration creates toxic liquid waste, efficiency highly pH-dependent |
| Adsorptive materials: activated alumina; activated carbons; other natural and synthetic adsorbents
|
Greater accessibility, low cost, simple operation, availability of wide range of adsorbents |
High efficiency often demand adjustment and readjustment of pH, some common water ions can interfere fluoride adsorption |
