|
| Process (name of the methods) | Type of environment | Removal performance | Advantages | Disadvantages | Ref. |
|
| Adsorption (exhaustive coffee grounds and iron sludge) | Groundwater | Iron sludge 62.92% and exhausted coffee grounds 56.67% | Cheap and easily available adsorbents | Low removal efficiency | [11] |
| Adsorption (porous starch loaded with common metal ions) | Drinking water | Maximum adsorption capacity of porous starch with Zr (PS-Zr) of 25.41 mg/g | Use of commercial scale | - | [82] |
| Adsorption (nepheline from alkali-hydrothermal) | Aqueous solutions | Maximum adsorption capacity of 183 mg/g | Cheap adsorbents | High efficiency and adjustment of pH | [83] |
| NF and RO | Groundwater | Fluoride rejection: 98% for RO and 90% for NF | High efficiency | Membrane fouling, decreased membrane lifetime and chemical persistence, high capital operation and maintenance costs, and hazardous effluent generation | [8, 22] |
| Ion exchange, membrane filtration, and EC | Aqueous solutions | 90%–95%, 99%, and 85.5% | High efficiency | Costly techniques, production of waste, and recommended for small community systems | [2] |
| Adsorption (purolite A520E resin) | Aqueous environments | 64.6% | Good stability and flexibility | Expensive processes | [84] |
| NF | Groundwater | 98% | High efficiency | High capital and running and maintenance costs | [27] |
| Adsorption (CuO NPs) | Aqueous solutions | 97% | High efficiency | – | [42] |
| Adsorption (Earth modified alumina) | Aqueous solutions | Adsorption capacity of F−: 26.45 mg·g−1 | Easy utilization and high efficiency | Limited yield and long exposure time | [46] |
| Adsorption (fungus hyphae-supported alumina) | Aqueous solutions | Nearly 90% | Economical and effective technique | Long exposure time | [85] |
| Freezing temperature | Water solutions | Deionized water spiked with fluoride 85% and salinity 75% | High efficiency and little contamination | More susceptible to the freezing temperature | [73] |
| Adsorption (diatomite modified with aluminum hydroxide) | Aqueous solution and natural groundwater | 89% | Low-cost | Leak of soluble alumina | [86] |
| Adsorption (zirconium onto tea powder) | Drinking water | Adsorption capacity of 12.43 mg/g | Effective, and safe biosorbent | A slight functional pH span | [87] |
| Adsorption (activated carbon: banana peel and coffee husk) | Aqueous solution | 80% to 84% | Cheap, simple, and environment friendly | Limited efficiency and long exposure time | [88] |
| Adsorption (single-walled carbon nanotubes) | Aqueous solution | 87%–100% | Low cost | Generation of toxic waste | [89] |
| Adsorption (Mg/Ce/Mn oxide-modified diatomaceous Earth) | Aqueous solution | >93% | Low cost and simple operation | High yield often demands adjustment of pH | [90] |
| Adsorption (aegle marmelos) | Aqueous solution | 52% | Low cost | Low efficiency | [91] |
| Precipitation/coagulation (lime and alum) | Aqueous solution | - | Simple process and little energy requirement | High cost of maintenance and production of hazardous waste | [1] |
| MOFs | Aqueous solution | Adsorption capacity of 41.36 mg/g | High surface area and high porous | – | [92] |
|
