Abstract:
In different regions across the globe, elevated arsenic contents in the groundwater constitute
a major health problem. In this work, a biopolymer chitosan has been blended with volcanic rocks
(red scoria and pumice) for arsenic (V) removal. The effect of three blending ratios of chitosan and
volcanic rocks (1:2, 1:5 and 1:10) on arsenic removal has been studied. The optimal blending ratio
was 1:5 (chitosan: volcanic rocks) with maximum adsorption capacity of 0.72 mg/g and 0.71 mg/g
for chitosan: red scoria (Ch–Rs) and chitosan: pumice (Ch–Pu), respectively. The experimental
adsorption data fitted well a Langmuir isotherm (R
2 > 0.99) and followed pseudo-second-order
kinetics. The high stability of the materials and their high arsenic (V) removal efficiency (~93%)
in a wide pH range (4 to 10) are useful for real field applications. Moreover, the blends could be
regenerated using 0.05 M NaOH and used for several cycles without losing their original arsenic
removal efficiency. The results of the study demonstrate that chitosan-volcanic rock blends should be
further explored as a potential sustainable solution for removal of arsenic (V) from water.
