Treatment And Resource Utilization Of Dredged Sediment In Baiyangdian

In recent years,with the unreasonable efflux of domestic waste in Baiyangdian,the development of aquaculture and surface tourism,more and more pollutants are discharged and accumulated in Baiyangdian waters,and the quality of water environment causes great concerns.Due to the increasing tension of land resources and the requirement for environmental quality,sediment dredging has been widely used as the main technology for internal cleanup of rivers and lakes.Through dredging technology to control river and lake pollution,the water environment can be quickly and thoroughly improved,and the water ecological balance can be restored.However,the amount of sludge generated after dredging is large with a large amount of organic pollutants,heavy metals,etc.If randomly stacked,this will cause serious secondary pollution.Therefore,the disposal of contaminated sediment is a serious problem.At present,effective treatment of contaminated sediment has reached a bottleneck in ecological environment management.Therefore,discovering new methods and finding new breakthroughs is a hot spot in this field.Considering the treatment and disposal of dredged sediment from the perspective of resource utilization,it can find a suitable way for large-scale dredged sediments,returning natural pollutants to nature,not only improving the natural environment,but also solving land resources as well.This paper carried out the research on the utilization of dredged sediment in Baiyangdian Lake.The research mainly includes three parts: First,the experimental study on land use of dredged sediment.Through soil column leaching,the changes of heavy metal concentration in the leachate under different mixing ratios and the degree of environmental impact were analyzed,and it was determined that the amount of sediment applied was about 40%.In this paper,the single-factor index and multi-factor index are used to analyze the pollution of leaching solution to groundwater.From the perspective of comprehensive pollution index,the groundwater pollution of each mixed sediment is not large,basically it is uncontaminated.From the single factor pollution index,Pb has the greatest potential risk to groundwater.As,Cr and Ni have different potential risks to groundwater.Through pot experiment,the growth status of Zinnia,Tall Fescue and Pakchoi is observed,and the biomass is measured.The amount of sediment obtained is the most beneficial for the growth of Tall Fescue.The ability of chromium,lead and arsenic is Cr>As>Pb.Second,the sludge solidification treatment and curing effect research.The ratio of curing agent is divided into 3 groups and 15 sub-groups.The unconfined compressive strength and solid waste leaching toxicity are analyzed to determine the amount of curing agent.Among,the treatment of quicklime: fly ash: bentonite:calcium sulfate of 2:2:1:2 showed the best curing effect.Third,the study of landscape mountain ecological restoration.Under the condition of the rainfall intensity of 1.9mm/min,a slope of 1:3,a 2 cm thick sediment,treated sediment of lime: fly ash:bentonite: calcium sulfate of 43:2:2:1:2,even at continuous rainfall for 1 h,the rainfall did not cause erosion on the slope.And the runoff liquid on the slope was found to have no pollution to the environment and would not cause secondary pollution of the sediment to the ecological environment.