Abstract:
Arsenic contamination in water bodies presents a significant health risk, particularly in rural areas in developing countries.
To treat arsenic-contaminated water economically in developing countries, it is crucial to propose low-cost water treatment
techniques. In this study, the arsenic treatment performance was investigated using continuous column adsorption
experiments packed with laterite grains taken from Tha.
ch Thát district, Hanoi, Vietnam. Initially, the physical and
physicochemical properties of tested samples were measured. The continuous column adsorption experiments were carried
out to assess the effects of initial arsenic solution concentration and calcination of tested grains (at 550◦C) on the adsorption
performance by using raw and calcined laterite. The results show that Scanning Electron Microscopy analysis with
Energy-Dispersive X-ray Spectroscopy confirmed the existence of iron oxides/hydroxides on the tested samples, which may
induce the arsenic adsorption affinity to laterite grains. Continuous column adsorption showed improved breakthrough time
with lower initial arsenic concentrations. The Bed Depth Service Time model suggested a minimum of 0.77 cm column
height for safe drinking water with 503.55 mg arsenic/L laterite adsorption capacity. Although the calcination didn’t
enhance surface area (raw laterite: 61.0 m2/g, calcined laterite: 60.2 m2/g), it improved arsenic treatment in continuous
column adsorption with enhancement of breakthrough time from 265min to 310 min. In summary, tested laterite grains
possess a high ability to treat arsenic contaminated water.
