Release of Arsenic from Arsenic Removal Water Filter Sludge in Soil and Its Uptake by Red Amaranth

There is a major concern among scientists over the elevated levels of arsenic (As) in drinking water in Bangladesh and some parts of India. Investigating the release of As from water filter sludge in soil and its uptake by plants may provide information about the management of As contaminated filter sludge. In this macrocosm study, iron based sludge containing granular ferric hydroxide (GFH) was mixed with air dried silt loam surface soil at rate of 0 (control, no sludge), 1.5 and 2.5 t·ha and red amaranth (Amaranthus tricolor L.) plants were grown for 45 days. Addition of filter sludge did not affect the height, fresh weight and dry matter yield of amaranth. However, the highest concentration of As and Fe were found both in shoots and roots of amaranth grown in the pot of the highest rate of sludge treated soil. The concentration of As, Fe and S was higher in the roots than that in the shoots of Amaranth. Translocation of As, S and Fe increased with the rates of sludge application. Elevated concentration of As in sludge treated plants is a sign of environmental hazard and should be taken into consideration.