Phosphorus In Lake Sediments And Heavy Metal Pollution Assessment Of Its Plant Repair

Baiyangdian Lake is the largest freshwater lake in North China and also the famous travel industry sites for water. Water quality has deteriorated and eco-environment has degraded because of the inside and outside pollution. Sediments, the intrinsic factor of water quality pollution, is as the main research object. Concentration change roles of Phosphorus (P) and forms, the limiting factor resulting in water eutrophication, and heavy metal Cu, Zn, Pb, Cd harming to biology in sediments are explored by the reed growth effect. It tries to search the feasibility of sediments bioremediation by reed in Baiyangdian Lake, and it aims to offer reference to remedy sediments and renew water-body eco-environment.Three treatments of different thickness were made with sediments from Baiyangdian Lake. Besides, soil from planting wheat field and reed field was also put into experiment as contrast Sediments and soils are collected periodically and the concentrations of P and forms and heavy metal Cu, Cd, Pb, Zn are mensurated. The date result is analyzed and estimated. Reed is collected homochronously and the concentrations of total P (TP) and heavy metal in the root, steam and leaf of reed is mensurated. The capability of reed enriching and assimilating contamination in sediments is analyzed.Following conclusions can be found by experiments and date analyses. The concentration of TP in sediments and soils is 794.86～878.97mg/kg and 451.49～ 641.17mg/kg respectively and the higher thickness of sediments, the higher concentration of TP higher; calcium P (Ca-P) and organic P (OP) are the main P forms in sediments and soils and the percent of them in TP is over 70%; the percent of iron P ( Fe-P ) in TP is under 10 % and the concentration of water soluble P is least, most the percent of which in TP is under 1 %; the remain of form is remnants P. Compared with 1995, the average .concentration of TP in sediments is higher than that in 1995 and the concentration of Ca-P is lower and the concentration of OP takes on distinct rise. Under the effect of reed growth, the concentration of P and forms don't distinctly fall, but obvious raise in some reed growth phase. It can be seen that the effect of reed remedying P in surface sediments is not obvious.