|
Method |
Method in Detail |
Advantages/Disadvantages | Reference |
|
Physical approaches | Mixing both contaminated and uncontaminated soils | High cost/usage to smaller-scale operations | [14] |
|
Physical approaches | Washed with sulfuric acid, nitric acid, phosphoric acid, and hydrogen bromide | Chemicals usage/high cost/usage to smaller-scale operations | [14] |
|
Physical approaches | Immobilise soluble arsenites using cement | Successfully used to stabilise As-rich sludges | [15] |
|
Physical approaches | Emphasis on stabilisation/solidification (S/S) | Treating As containing wastes in water | [15] |
|
Physical approaches | Soil flushing using aqueous solutions using surfactants and cosolvents | Applied in the field, efficiency can vary from 0% to almost 100% | [16] |
|
Chemical remediation approaches | Adsorption by using specific media, immobilization, modified coagulation along with filtration, precipitations, immobilizations, and complexation reactions | Economic but often displayed lower efficiencies (<90%) | [1, 14] |
|
Chemical remediation approaches | Formation of stable phases, for example, insoluble FeAsO4 (and hydrous species of this compound such as scorodite, FeAsO4.2H2O) | Use of selective stabilizing amendments is a challenging task | [17] |
|
Chemical remediation approaches | Stabilization method using nanosized oxides and Fe(0) (particle size of 1 to 100 nm)
| Gained popularity/high success rate, but it could be expensive when remediating a large area | [14, 17–19] |
|
Intrinsic bioremediation | Degradation of arsenic by naturally occurring microorganisms | More suitable for remediation of soil with a low level of contaminants | [14] |
|
Engineered bioremediation | Optimizing the environment conditions to promote the proliferation and activity of microorganisms | Favorable method used in high contaminated area | [14] |
|
Microbial oxidation | Immobilization of As in the solid phase | Required biological activity, and microbiological molecular analysis/involved adsorption or coprecipitation with Fe-oxyhydroxides. | [20] |
|
Physiochemical methods | Filtration or coagulation sedimentation, osmosis or electrodialysis, adsorptions, and chemical precipitations | Widely accepted in some places | [14] |
|
Biological methods | Such as phytoremediation by using aquatic plants or microbial detoxification of arsenic | Widely accepted in some places | [14] |
|
Phytoremediation method | Using “free-floating plants such as water hyacinth” | Widely accepted in some places | [14, 21–23] |
Using aquatic rooted plants such as Agrostis sp., Pteris vittata, and Pteris cretica |
|
Methylations | Biomethylations (by As(III) S-adenosylmethionine methyltransferase) | Is a reliable biological process of removing arsenic from aquatic mediums | [14] |
|
Reduction | Reduction of arsenate into arsenite by microorganisms via dissimilatory reduction mechanism | Should be carried out in facultative anaerobe or strict anaerobe condition | [24] |
|
Oxidation | Using heterotrophic bacteria and chemoautotrophic bacteria to oxidize arsenite into a less toxic arsenate | Should be carried out in controlled environment | [4, 14, 25–28] |
|