| Adsorption |
Rocks, soils, minerals, industrial by-products, biosorbents, biochars and microalgal and fungal biomass |
95% |
Safe operation, easy handling, flexibility, cost-effective, sludge-free, and high removal efficiency |
Sorbents require replacement once the adsorption bed becomes saturated and exhausted, eventually losing its separation capacity. They lack self-monitoring capabilities and have a low specific surface area when metal oxides are used. Additionally, they are only suitable for wastewater with low arsenic concentrations |
74–78
|
| Ion exchange |
Natural polymeric materials or synthetic organic substances |
97.9% (pH: 3.5–7) |
Complete removal and recovery of metal substances, with minimal production of toxic sludge |
Requires regular regeneration to maintain full removal efficiency; expensive; each exchanger is specific to a particular As species; has an unfavorable selectivity order; the resin is more reactive to natural anions; lowering the pH, which may lead to potential corrosion problems |
74 and 79–81
|
| Phytoremediation |
Innovative approaches and plants (phytobial, phytoextraction, phytostabilization, phytofiltration, and phytovolatilization, nanophytoremediation) |
99.9% |
High quality, efficiency and effective for aquatic system; environmentally friendly and economically valuable; preventing the spread of contaminants in land restoration |
The most cost-effective treatment methods, widely accepted socially across the globe; a time-consuming process; climate and tropical zones impact many hyperaccumulating plants; microbes generate additional toxic substances; lacks widespread applications; hazardous pollutants interfere with the plants' metabolic processes, hindering their growth and development |
82–86
|
| Nanophytoremediation enhances the efficiency of phytoremediation, supports in situ remediation, boosts the degradation of pollutants into less toxic forms, and is cost-effective |
| Chemical precipitation |
Reagents such as Fe salts, sulfides, mg, and Ca salts |
95% |
Straightforward and efficient; targets specific components for removal |
Consistently forms silt; associated with high processing costs |
87–90
|
| Electrocoagulation technique |
FeCl2; FeSO4; Al2(SO4)3
|
99.9% |
A new and promising approach for As removal in drinking water; efficient, cost-effective, easy to maintain, and operates with locally available materials |
Ineffective for extracting AsIII; generates contained sludge with high energy consumption; highly influenced by the form and dose of coagulants, solution pH, and the presence of other competing anions |
91–94
|
| Membrane technology |
Microfiltration (MF), nanofiltration (NF), ultrafiltration (UF), and reverse osmosis (RO) |
96% |
Excellent efficiency, low energy consumption, and superior filtration performance; applicable for various separation methods |
High costs and significant water rejection |
95–97
|
