Electronic Thesis and Dissertation Repository


Master of Engineering Science


Chemical and Biochemical Engineering


Ray, Ajay K.


Arsenic poisoning in water is a global concern for many years due to its high carcinogenic and toxic effect on the human body. Adsorption is one of the promising technology to treat arsenic-contaminant water. Recently, natural adsorbent modified with metal oxide/hydroxide is being studied widely, because of its great removal efficiency, inexpensive and eco-friendly properties.

In the present study, two low-cost adsorbents namely Aerocrete and Vermiculite (modified with iron oxy-hydroxide) were assessed for arsenic (both As(III) and As(V)) removal. The maximum removal of As(V) was ~99% at pH 6 for both adsorbents (3g/L). Optimum removal of As(III) was observed at a pH range of 6 to 8. Both Langmuir and Freundlich isotherms described the adsorption equilibrium data. A pseudo-second-order kinetic model fitted well with the experimentally obtained kinetic data. No significant effect on the adsorption of As(III) was observed in the presence of ions (i.e., Ca2+, Mg2+, Na+, HCO3-, SO42-, or Cl-). Results showed that the proposed adsorbents (Aerocrete and Vermiculite) are promising in removing As(III) from the water.