Removal of aqueous As(III) and As(V) by hydrous titanium dioxide

摘要

Dissolved arsenic in drinking water is a global concern as it causes serious health problems. The purpose of this research was to study the applicability of an industrial intermediate product, a mixture of titanium hydroxide and titanium dioxide for removing aqueous arsenic. The material is common, inexpensive, and non-toxic, making it an attractive choice for drinking water purification. The kinetics and equilibrium of removing both primary inorganic arsenic forms, As(III) and As(V), were studied by separate batch experiments. The tested material functioned well in removing both of these arsenic forms. The apparent values for Langmuir monolayer sorption capacities were 31.8mg/g for As(III) and 33.4mg/g for As(V) at pH 4. The studied TiO_2 performed the best in acidic conditions, but also reasonably well in other pH conditions.