Research On Biofilter Media Made From Dredging Sediment And Its Effect On Wastewater Treatment

Dredging sediment containing a large number of microorganisms,pathogens, heavy metals and organic pollutants would cause serious enviromental pollution when improperly proposed. In this thesis, we tried to use dredging sediment to make substrates to be used in sewage treatment in order to find a way for the proposal of this solid waste and saving clay resources. This research showed that the main chemical composition in the sediment is similar to clay, providing a possibility for utilization of sediment to make the substrate.In this experiment, the dredging sediment was made into spherical and bowl-like substrates by sintering and cementation. The optimum sintering process was achieved by seting up different raw material composition and roasting temperature in the experiment and the result was as follow:100% dredging sediment,calcination temperature 1100?.The performance parameters of the sintering ball sediment filtering comply with relevant standards. The bowl-like filtering substrate was made by the cementation process.The two kinds of substrates made from dredging sediment and ferments from organic solid waste was utilized to setup MSL biofilter system for wastewater treatment experiment. The results showed that both sintering spherical and bowl-like substrates used in MSL and biological filter system could effectively remove pollutants from restaurant wastewater.Removal effect of sediment substrate in MSL were generally poorer than regular filtering,which was composed of zeolite and ceramsite.Cementing bowl filtering used for wastewater treatment also has certain pollutant removal effect,especially for TN and TP in the wastewater.It can be concluded that it is feasible to use dredging sediment to make wastewater treatment substrate.The effect of applying organic leavening for MSL system to treating wastewater from restaurant was not ideal. The wastewater treating effect of sediment filtering used in MSL system was better than the biological filtering.Therefore, it is feasible to reuse the dredging sediment as filtering for wastewater treatment.