Effect Of Ultrasound On Heavy Metal Accumulation Of Aquatic Plants In Sediments

With the in-depth study of heavy metal in aquatic system, the problem of treating the heavy metal pollution in water system had got more and more attention. It has become the hot spot that use the aquatic plants ability of the tolerance and accumulation to remove heavy metal pollution. Four southern common aquatic plants(Myriophyllum spicata, Hydrilla verticillata, Ceratophyllum demersum and Spirogyra) were used to investigate the accumulation ability of aquatic plants to heavy metals, utilizing the soil sample in Chenzhou as sediment, cultured by combination of two and individually, and combined with different times of ultrasonic ranged from0minute to5minutes, then trained for a week in simulating condition. Compared of the growth of various algae(including individually and combination of two), after treated by hydrochloric acid, nitric acid and high chlorine, digested for a night, then determined by atomic absorption spectrometry.The main conclusions were as follows:(1)Four kinds of algae selected in the experiment all had different degrees of growth, especially the Myriophyllum spicata. The growth of Spirogyra combined with different times of ultrasonic was lower than other three kinds of algae. Even in culturing with Myriophyllum spicata, the growth rate was negatively(average was-8.48%). In general, the growth rate of combinations was much more than the individuals.(2)If only one kind of aquatic plants can be used to treat the heavy metal contamination in the sediment, Hydrilla verticillata cultured individually can be used to treat copper pollution; Myriophyllum spicata cultured individually can be used to treat lead pollution;Ceratophyllum demersum cultured individually can be used to treat zinc, cadmium, arsenic, mercury single and combined pollution.(3)If two kinds of acquatic plants can be used to treat the heavy metal contamination in the sediments, Ceratophyllum demersum cultured with Myriophyllum spicata can be used to treat cadmium pollution; Ceratophyllum demersum cultured with Spirogyra can be used to treat mercury pollution; Ceratophyllum demersum cultured with Hydrilla verticillata can be used to treat copper, zinc, lead, arsenic single and combined pollution.(4)If conditions permitted, two kinds of acquatic plants combined with certain ultrasonic can be used to treat the heavy metal contamination in the sediment. The Ceratophyllum demersum cultured with Hydrilla verticillata combined with2minutes of uslsonic can be used to treat copper, zinic, arsenic single and combined pollution. The Ceratophyllum demersum cultured with Myriophyllum spicata combined with2minutes of ultrasonic could be used to treat lead, cadimium, mercury pollution.