The use of duckweed for removal of heavy metals and organic compounds from wastewater in As-Samra

Aquatic plants like duckweed can be applied for waste-water treatment. Duckweed is a small aquatic plant, well-known for its high productivity. Eighty percent of the wastewater generated in Jordan is treated at the Khirbet As-Samra wastewater treatment plant for eventual use in agriculture. In this study, three duckweed ponds were constructed close to the outlet of maturation ponds of Khirbet As-Samra wastewater station. One pond was used as a control pond and the other two for duckweed experiments. Duckweeds were transferred from Al-Ghor area to the duckweed pond to form a thick layer on top of water. The plant efficiency for removal of the organic substances such as: COD, phenols, detergents and heavy metals (Cr, Cu, Pb and Zn) were examined in the winter and spring seasons. It has been found that the average percentage removal of these parameters were as following (%): COD 22 and 30, phenols 24 and 37, detergents 29 and 52, Cr 13 and 33, Cu 15 and 33, Pb 10 and 24 and Zn 17 and 36, in the winter and spring seasons, respectively.