Various sources of organic matter (namely poultry litter, cow dung and sewage sludge) were used to remediate arsenic accumulation in plants (Ipomoea aquatica) in a pot-culture experiment. Organic matter was applied at the rates of 5 t/ha and 10 t/ha to soils spiked with arsenite at 20, 50 and 100 mg As/kg soil. Plants were grown for 30 days after germination. The presence of arsenic in the growth medium had a negative impact on the vegetative growth of the plants, for both organic matter treatments and control. However, organic-matter application had a more positive effect than no application, at all levels of arsenic spiking. Poultry litter performed the best, and at the application rate of 5 t/ha, the vegetative growth was more than 81.55% over the control; whereas the increases were 17.74% and 10.98%, respectively, for cow dung and sewage sludge at the same rate of application. Organic-matter application was able to reduce arsenic accumulation by as much as 75% in the vegetative part of the plant. For the various sources of organic matter, the performance in reducing the accumulation of As in Ipomoea aquatica followed the order: poultry litter > cow dung > sewage sludge.

Key words: arsenic, Ipomoea aquatica, organic matter, remediation

Land Contamination & Reclamation, 16 (4), 2008