Reaserch on phytoremediation of cadmium contaminated water by three submerged macrophytes

Abstract:

The study is about the growth and cadmium′s restoration effect of three submerged macrophytes（Ceratophyllum demersum L.，Elodea nuttallii and Vallisneria natans）in different pH and cadmium.The result shows that, three submerged macrophytes can all tolerate the pollution of cadmium in a certain concentration range,and eliminate cadmium of the water to different degree. Ceratophyllum demersum L.and Elodea nuttallii have strongest elimination ability of cadmium under pH 8.5 or 15 μg/L cadmium. Vallisneria natans has strongest elimination ability of cadmium under pH 7.5 or 10 μg/L cadmium. Among these living submerged macrophytes,Elodea nuttallii has the strongest tolerate and elimination ability of cadmium (up to 92%), then Ceratophyllum demersum L.(up to 90%), and Vallisneria natans (up to 66%). The elimination ability of the 3 submerged macrophytes’ powder is more obvious than its living form, Elodea Canadensis’s powder has the strongest elimination ability of cadmium (up to 95%), then Ceratophyllum demersumL. ’s powder (up to 93%), and Vallisneria natans’s powder (up to 88%).But the elimination ability of cadmium by Vallisneria natans’s powder is less vulnerable to the pH and the cadmium concentration (range between 81% and 88%). The three submerged macrophytes adaptation scope very broad,efficient and pollution free, they could be successfully used for heavy metal removal from waste water containing cadmium.