Physical, Chemical, and Biological Methods for the Removal of Arsenic Compounds

Table 1

Advantages and disadvantages of methods for the removal of arsenic compounds.

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]