Research On Phytoremediation Of Eutrophic And Organic Pesticide Polluted Water Body

Phytoremediation is a promising technology that uses plants to assimilate, degrade and metabolize pollutants in the environment. As this technology remediates contaminated soil, sediment, water and air in situ through the ways of transfer, degradation or fixation of pollutants, without transferring pollutants to special treatment plants, enormous costs of transport, disposal and storage can be saved.Eutrophication and organic pesticide pollution of water body are major problems of water pollution. In this thesis research, the capabilities of six aquatic plants (Typha angustifolia, Scirppus Validus, Acorus tatarinowii Schott, Sagittaria sagittifolia.L, Zizania caduciflora (Turcz.ex Trin.)Hand. and Juncus effuses Linn) to remove nutrients (nitrogen and phosphosrus) in eutrophic water were studied by using artificial nutrient solution as growing culture. In the artificial eutrophic water with different inorganic nitrogen loads, the removing effects of nitrogen and phosphorus of Typha angustifolia, Scirppus Validus, Acorus tatarinowii Schott were compared, and the effects of different inorganic nitrogen concentrations to phytoremediation were discussed. In addition, the microbial community structure as well as its developing trend of selected water samples from these treatments was also analyzed by PCR-DGGE method.The following conclusions are worked out from the research of phytoremediation of eutrophic water by aquatic plants:1) In artificial eutrophic water, the sequence of nutrient removal abilities of the six plants is: Scirppus Validus>Typha angustifolia>Zizania caduciflora (Turcz.ex Trin.)Hand> Sagittaria sagittifolia.L> Juncus effuses Linn and Acorus tatarinowii Schott.2) In eutrophic water solutions with a heavier nitrogen load (approximately 25 mg.L^-1 inorganic nitrogen load), when the experiment terminated, the concentrations of nitrate in water solutions were higher than the initial concentrations;while in eutrophic water solutions with a lighter nitrogen load (approximately 15 mg.L^-1 inorganic nitrogen load), when theexperiment terminated, the concentrations of nitrate in each water solution were lower than the initial concentrations, with the concentration sequence of Scirppus Validus Typha latifolia> Acorus tatahnowii Schott. The effects of pollutant reduction of plants are closely related to the growth situation of plants.2) The removal of dimethoate by Scirppus Validus is conformed to the first order dynamic equation with the degradation consistent K of O.OOQd"1. Within 16 days of the experiment, the reduction percentage of dimethoate was 78.6%.3) There was no intermediate product detected in the experiment process of dimethoate removal.