Elements

Adsorbents

Characteristics

Efficiency

References

B

Polyaniline-Boron nitrate compound or white Graphene.

Good porosity, good adsorbent, high pore space.

Fair adsorbent but P^H dependent

[56]

C

Novel carbon, activated carbon, biochar, fresh organic matter, humus, carbon nanotube, seed shell carbon.

Easily synthesized, good porosity, high surface area, abundant in nature, easily handle, good carrier

Good adsorbent, efficiently remove Cr from water

[43] [49] [50] [57] [59] [60] [61] [62]

Si

Silica sol-gel, Sodium metasilicate pentahydrate

Good surface area, good porosity, abundant, cheap

High potentiality when incorporating with sulphonic acid

[63]

Al

Metal organic framework, activated alumina

Good porosity, good porosity, low surface area, aeration capacity,

Metal Aluminum is a good adsorbent but Alumina is not much efficient

[64] [65]

S

Sulphonic acid and S containing compound

Efficiently perform in Cr (III) removal but not for Cr (VI). Work as a catalyst.

[66]