Arsenic adsorption on rusting iron nails

The objective of the study was to sequestrate inorganic arsenic from groundwater using 6 mm rusting iron nails as well as to know maximum adsorption capacity of arsenic per g nail, rate of adsorption (k) at different ages of nails by batch study and to know practical applicability of nails by column study at pH around 7.5. It is observed that rate of removal for As(III) is slightly better than As(V). Maximum adsorption capacity was found for anoxic As(III), anoxic As(V), oxic As(III) and oxic As(V) were found as 528.32, 488, 531.87 and 516.25 mu g per g of nail respectively when the initial concentration was 500 mu g/L. Breakthrough for anoxic As(III), anoxic As(V), oxic As(III) and oxic As(V) were found in 186, 163, 174 and 176 days respectively when the initial concentration of 500 mu g/L was used for each case on a daily basis. W-Scanning Electron Microscope (W-SEM) and Energy Dispersive X-Ray Spectroscopy (EDS) results showed evidence of surface deposition of arsenic on iron nails. XPS results showed the formation of different oxides with arsenic on the iron surface. A 7 cm diameter and 11.5 cm long column having 1500 g rusting nails were used to know practical applicability of rusting nail iron nails to sequestrate arsenic from water. 380 lit. As(III), 240 lit. As(V) and 200 lit. 1 : 1 total arsenic of 100 mu g/L was passed through the column at flow rate of 32-40 ml/min before outlet concentration coming above 10 mu g/L.