Keywords: activated alumina, adsorption, arsenic, desorption, portable filter
Development of a portable filter for arsenic removal from drinking water
In the present study, different grades of indigenously available activated alumina (AA) were screened for their arsenic removal capacity. For both As(III) and As(V), A1 (Grade 1, 0.3-0.6 mm) activated alumina has shown better removal efficiency. The optimum pH for the adsorption phenomena was around 7.0. Chlorine at a dose of 20 mg/l could completely oxidize As(III) to As(V), which also assured the bacteriological quality of the water. Among various anions studied, sulfate seems to have maximum competition with arsenic for adsorption sites. A portable filter with a flow rate of 6 l/h and a contact time of 5 minutes could effectively be used for the treatment of arsenic contaminated water. The exhausted activated alumina could regenerate with 4% NaOH solution without much reduction in efficiency.