New Generation Material for the Removal of Arsenic from Water - Advanced Materials for Agriculture, Food and Environmental Safety - page 70

Table 3.6 Soils and constituents with dif erent parameters.

Adsorbent pH Concentration

range

Capacity (mg/g)
As(III) As(V)

Ref.

Olivier soil 5-6 5-100 mg/L - 0.42 [82]

Iron oxide
coated sand

- 100 μg/L 0.136 - [83]

Iron oxide
coated sand

- 325 μg/L - 0.018 [84]

Modii ed iron
oxide-
coated sand

7.2 0.5-3.5 mg/L 0.14 - [85]

(SMIOCS) 4-10 0.5-3.5 mg/L 0.13 (pH 4), - [86]

0.12 (pH 7),
0.08 (pH 10)

Goethite - 5-25mg/L - 5 [87]

ZMA (Sonora) 4 0.1-4 mg/L 0.0048 0.1 [90,

91]

Shirasu-zeolite
(SZP 1 )

3-10 1.3 mM - 65.93 [92]

3.1.5.8.2 Clay Minerals and Zeolites
Clay minerals and oxides are widespread and abundant in aquatic and ter-
restrial environments. Finely divided clay minerals and oxides exhibit large
surface areas. Clay minerals and oxides adsorb the cationic, anionic, and
neutral metal species. h ey can also take part in the cation and anion-
exchange processes. h eir sorption capacities, cation and anion-exchange
properties and binding energies vary widely. h e goethite (surface area
103 m 2 /g) prepared from the oxidation of ferrous carbonate from double
decomposition of ferrous sulphate doped with sodium lauryl sulphate and
sodium carbonate was also used for arsenate removal [87]. Adsorption
capacity of 5 mg/g (pH 5.0) was achieved.
Zeolites have received increasing attention for pollution control as
standard components in wastewater treatment [88]. Both ion exchange
and adsorption properties of zeolites have been used for the selective
separation of cations from aqueous solution. Zeolites are crystalline,
hydrated alluminosilicates of alkali and alkaline earth cations, having
ini nite, three-dimensional structures [89]. Aqueous arsenic sorption