Removal of heavy metals from wastewater by natural growing plants on River Nile banks in Egypt

Abstract

Green remediation is a known technology that uses different types of plants to extract contaminants from the environment. This study aims to remove heavy metals from treated wastewater by using natural growing plants on River Nile banks in Egypt. Secondary treated effluent was collected from West Gerga wastewater treatment plant located in Sohag city, Egypt. Experiments using two types of aquatic plants were carried out. They were planted individually and in combination with different densities on the secondary treated wastewater surface for 10 days retention time to remove cadmium (Cd), nickel (Ni) and lead (Pb). It was concluded that both plants have high capabilities to remove heavy metals directly from treated wastewater. The removal efficiency of Cd and Pb was higher when they are planted together than that of individually planted. A positive relationship was observed between detention time and heavy metals removal. The removal efficiency of heavy metals increased with the increase of plants density for both plants types. Also the availability of aquatic plants and their free cost makes their use an economically attractive alternative. In addition, the removal of these plants from River Nile improves the performance of water distribution networks in Egypt.

Effect of Pb-Contaminated Water on Ludwigia stolonifera (Guill. & Perr.) P.H. Raven Physiology and Phytoremediation Performance

“…The results reported that lead removal efficiency (RE) increased with increasing exposure time and concentration. Comparable results have been obtained by Abd-Elaal et al [ 6 ] in Echinochloa pyramidalis and Ludwigia stolonifera with removal percentages of heavy metals (Pb, Cd, and Ni) between 77 and 95% in 10-day incubation period. This may be attributed to the fact that most of the active sites are occupied by toxic metal from surrounding media [ 19 ].…”

“…The results reported that lead removal efficiency (RE) increased with increasing exposure time and concentration. Comparable results have been obtained by Abd-Elaal et al [6] in Echinochloa pyramidalis and Ludwigia stolonifera with removal percentages of heavy metals (Pb, Cd, and Ni)…”

“…The BCF value of L. Stolonifera was greater than 1000 in the recent study, indicating that it could be considered a strong lead accumulator. The Pb BCF has also been found in the following species: Najas indica [ 20 ], Pistia stratiotes [ 21 ], Acorus gramineus [ 22 ], Ludwigia peploides [ 23 ], and Echinochloa pyramidalis [ 6 ]. Similarly, TF values greater than one suggest that the plant has substantial metal translocation pathways to the leaves [ 22 , 24 , 25 , 26 ].…”

“…Pb is also dangerous to plants in the same way that it is to humans. Lead accumulation in plants boundaries photosynthesis and enzyme function and disrupts the water and nutrient balance, resulting in stunted growth and chlorosis [ 6 ].…”