Submerged Plants On Copper Enrichment Studies

The heavy metal contamination in the environment comes from the heavy metal waste water produced by the non-ferrous metal smelting and processing. As a result of complex of non-ferrous metal raw materials, leading to higher heavy metals concentrations, wider ranges of concentration and wider ranges of pH in the wastewater. According to investigation, the copper contents in non-ferrous wastewater are about 1～200mg/L, pH values are about 1-7. Based on the investigation above, the copper enrichment capacities of three submerged macropHyte, Elodea densa (Planch.) Casp., LimnopHila aquatica, and Cabomba caroliniana Gray, were studied and screened. Screening result indicated that Elodea densa (Planch.) Casp. had better copper-concentration and better tolerance to copper. The Elodea densa (Planch.) Casp.'s advantages of the copper-rich are showed below:larger preconcentration:the Elodea densa (Planch.) Casp. had a much stronger copper-rich capacity. BCF reached to 2118.73. The largest enrichment of copper reached to 41400mg/kg. Shorter enrichment time of copper:Elodea densa (Planch.) Casp. has reached the maximum amount of enrichment at different exposure concentrations in 6-8 days.the largest adsorption quantity had no relation to concentration of exposure. Elodea densa (Planch.) Casp. had better tolerance to copper:Elodea densa (Planch.) Casp. has gotten to the maximum concentration of copper-rich in the eighth day although the copper has had a toxic effluence on it. Elodea densa (Planch.) Casp.'s advantages provide test data and technical methods for development and utilization of it in the treatment of non-ferrous heavy metal waste water. The results show bellow1. Used of semi-static test method, we studied and screened the copper enrichment capacities of three submerged macropHyte, results show that:the Elodea densa (Planch.) Casp. had a strongest copper-rich capacity, BCF reached to 2118.73. The largest enrichment of copper reached to 41400mg/kg, far much higher than the other two plants.2, Used of semi-static test method,we studied factors impact on copper enrichment of the Elodea densa (Planch.) Casp., results showed that: The influence of Concentration of copper impact on the copper-rich capacity of Elodea densa (Planch.) Casp.:BCF of Elodea densa (Planch.) Casp. increased with exposure to lower concentrations, BCF20> BCF40> BCF60≈BCF80> BCF100.The influence of pH value change impact on the copper-rich capacity of Elodea densa (Planch.) Casp.:pH value affect obviously on the copper-rich capacity of Elodea densa (Planch.) Casp., with the lower pH value, the Elodea densa (Planch.) Casp.'s enrichment of copper reduce Rapidly.3,enrichment model fitting study of Elodea densa (Planch.) Casp.Enrichment model fitting study:Used experimental data of copper enrichment of Elodea densa (Planch.) Casp. to fit two boxes of enrichment model, we can see that the fitting coefficients of the concentration of the test data is between the 0.78～0.996, the two box model can reflect the basic Elodea densa (Planch.) Casp.'s bioconcentration process of copper, the two box model is applicable to Elodea densa (Planch.) Casp.'s bioconcentration process of copper.4,Used of semi-static test method, we studied the largest Elodea densa (Planch.) Casp.'s enrichment of copperAt different exposure concentrations, Elodea densa (Planch.) Casp. has reached the maximum amount of enrichment in 6～8 days, the largest enrichment of copper is 41400mg/kg, and the largest amount of enrichment and concentration of exposure has not related.5,Used of static test method, we studied the removal of Elodea densa (Planch.) Casp. to copper ionsIn static culture conditions,25g Elodea densa (Planch.) Casp. exposed in 2L 100mg/LCu2+ solution for 8 days.After 8 days the removal rate was 15.12%.6,Used of semi-static test method,we studied preliminarily the toxic effluence of copper affact on Elodea densa (Planch.) Casp.At different exposure concentrations, Elodea densa (Planch.) Casp. cultured 8 days, the leaves appear chlorotic, curled phenomenon has become very soft, plant weight decreased significantly. Under the same exposure concentration, the phenomenon of chlorosis is more obvious with pH lower; At different exposure concentrations, Elodea densa (Planch.) Casp.'s chlorophyll content reduced while the exposure concentration and exposure time increased; The malondialdehyde (MDA) content increased while the exposure concentration and exposure time increased;At 20mg/L exposure concentration, the different acidity affect Elodea densa (Planch.) Casp.'s content of chloropHyll more seriously. The chloropHyll content reduced while acidity and exposure time increased. The malondialdehyde (MDA) content increased while acidity and exposure time increased.